sootie007

Thanks Cain...I think this is about as sensible a cheap old school combo for this 305 as you can do yet reuse some of the pieces down the road on a real motor /combo. I cant wait to get it completed in the next few weeks too ! Its really hard to do this with two small kids running around AND to justify that time away from them and commitments. HeXX before kids I would have had this swap knocked out in 2-3 weeks not 2-3 months lol . Being heavy on appearance and doing it right the first time doesn't help the schedule either - my personality . Everything with me has to be just so , in its place and look good lol. Waay too ****.

sootie007

Pulled the leaking pipe plugs out of the Mallory Fuel pressure regulator and sealed them with this Rectorseal #5 .....its yellow , comes in a toothpaste sized container , and comes out like gritty toothpaste , ~ $4 at Home Depot on the plumbing aisle . I couldn't nail down the cure time for gasoline searching around , it says some fluids can take up to 48 hrs...SOOOO to be cautious I will wait the full 48 as gas is probably the worst case fluid. I didn't see any thread damage etc in the FPR or on the 2 brass pipe plugs ????? This stuff should seal it and is gasoline safe.

I went ahead and connected the Flowtek Y - pipes to the shorty headers so that's good to go ...I will need to rig up a cat converter test pipe to the mid pipe to Y pipe junction and that exhaust will be 100% done. I have a Dynomax super turbo muffler on it ...it was pretty quiet with the stock cam , stock manifolds and cat delete . I don't expect it to be much louder with the cam and headers truthfully and I may change it out .

PS If you ever need an o2 sensor bung plug and Home Depot is out of the size you need you can use this Dorman oil plug P/N 65220 its M18-1.5 ..Advance Auto.

UPDATE 5-9-2014 I put a thin glob of the Rectorsel on my bench top and allowed it to "cure" for the 48 hrs and it never hardened ???? Maybe its not supposed to ? But the regulator fittings ARE NOT leaking now after its application - so who knows.

UPDATE 7-17-14 This Rectorseal stuff really didn't work- I am going to use good old Teflon tape to stop the seeping .

UPDATE 8-4-14 Teflon tape worked ...so paste was a total waste of money.

sootie007

Headers and Y pipe photos...Headers are Summit shorties , Flowtek Y pipe ...I coated them with VHT Flameproof primer and paint .

sootie007

Waiting the full 48hrs on the pipe thread sealer at the regulator it was time to fire it up tonight .....after probably 6 times trying to start it and fudging the distributor to advance - retard etc it finally started. It ran like crap but not too bad no huge backfires etc and after around 30 secs I shut it off after seeing what I thought was header paint smoke ...... I need to get a timing light on it to verify the initial timing.
Heres the list of stupid things I did admittedly to help others ......

Forgot to stab the new dipstick in , the previous owner broke the old dipstick and I simply forgot to put the new one in the block I bought...oil all over the starter and down the side of the block .....lots o smoke .

Forgot to put the gauge sensor in the intake which I had covered with tape and painted over high temp silver so it blended in great. I saw coolant pooling around that intake bolt hole below it and thought damX I have a head cooling port leaking OR I didnt torque those bolts down tight enough around that head water port ...I tightened them down again ...dabbed the coolant up with a rag ran it again for about 20 seconds from inside the car ...came back out coolant all over the bolt hole again and then duh I saw it was leaking from the taped over painted bung on the intake (Dummy) . So I will put the sender unit in that hole tomorrow.

I had the timing too advanced I am theorizing and in those 30 secs my brand new primed and painted VHT Flameproof headers I was so proud of pimpled all up in those brief 30 seconds and basically fuxxxx the excellent $$$$$ paint job up on the brand new headers .....

The good ....I apparently wired the HEI wiring for the distributor correctly - tach was working too.

I have no leaks anywhere so far in the an fuel lines I made or at the metal body fuel line connections.

I just didn't want to pixx the neighbors off so I will go back at it tomorrow.

Things I don't know yet .....what fuel psi is it running after 2 secs or is it running at all after 2 secs ....I will have to set my iphone video up to record it while I am in the car for say 30 sec keeping it running with throttle to verify I have constant fuel pressure. If not I will have to mod the fuel pump relay wiring.

I didn't notice if my cooling fan came on - probably not ....didn't get hot enough.

What initial timing I have- set up my timing light tomorrow on it .

Work on getting it to idle by itself .

sootie007

I got a timing light on it tonight and I was pretty off by about 20 degrees ..... I have it at 8 initial now and it fires up right away and idles pretty good for having no carb adjustments done at all yet ........

Loose ends ...I need to do the fuel pump wiring mod as I only get 2 seconds of pump prime then it goes to zero psi as expected .

I got the dipstick in so no more oil leak from there .......

I have an oil leak up front and low somewhere.

And possibly one of the water pump to block gaskets has a slight drop leak.

I will modify my Cat test pipe to fit the new Flowtek midpipe tomorrow as its open exhaust at the end of the midpipe right now and sounds like a well used tractor .....

So I have quite a few loose ends to take care of tomorrow but definitely made progress tonight !

Depending on tomorrows progress I might be able to take it for a brief spin as I haven't put the overdrive control in it yet .

sootie007

Got the exhaust sealed back up, Fixed the oil pan leak with red gasket maker. Tomorrow I should be able to get the gauges in , do the fuel pump wiring mod , work on the tune and take it for a spin finally.

sootie007

Found a bad temp sensor below the passenger head so my single fan wasn't turning on. I removed ac from my car . (In ac cars I read as soon as ac is set to "on" the fan normally energizes.) So I decided to modify the relay wiring for my fan.....I am in Florida , never need heat so I decided to mod it so it turns on as soon as you start the car and stays on. The Fan relay is on the Firewall to the left of the Fuel pump relay. ....to accomplish that I simply took the green and white stripe wire on the relay and spliced into it and ran / connected this spliced wire to the Firewall. The Firewall is gnd. My fan now comes on as soon as I turn the key and stays on. One wire and its done. I used the same gage wire as the Green / white striped wire .

Fuel pump wiring mod is next ......it is currently shutting off after the 2 seconds of ignition prime.

sootie007

So I guess I hit the bad sensor lottery ...I was troubleshooting my fuel pump issue ...I would get the 2 second prime but then the fuel pump would immediately shutoff ....it was the 1991 oil pressure switch / sender causing the problem. See attached Duralast P/N PS207 $33 part from Autozone that fixed it. This switch is located above the oil filter on the 91 305 TBI .

So on my 91 RS 305 TBI - to Carb swap there was no need to do any wiring mods AT ALL to the fuel pump wiring or its relay circuit ...apparently on startup you get a 2 second prime from the ecm to get things started , then the oil pressure switch detects greater than ~ 6 psi from cranking - closes the switch which enables the fuel pump relay on solid from that point on to keep fuel flowing constantly.

So I finally fired it up for an extended run with the exhaust buttoned up for the first time and noted a few things........

This GMPP Ramjet cam sounds wimpy with my single Dynomax super turbo muffler lol ...its borderline not even as throaty as a 70' s station wagon..... it IMMEDIATELY fires up and idles damn near like a stocker. I didn't take a vacuum reading but I am guessing its got 20 " the way it sounds . I may not even bother getting a Flowmaster in there to liven it up - I don't think it will help lol.......no lope 109 LC and all in a small 305 ,zero and I MEAN zero valve train noise , no poppiness with 9.3:1 , shorty headers, no cat and single Dynomax crossflow super turbo to 2.5" dual tips. This cam is used in the 350 horse RAMJET 350 crate motor 400 ftlbs @ 3500 and the High Torque -HT383 340 hp 435 ft lbs from GMPP. Its a torque grind and has no "attitude" sound at all to it . Flat as a pool table torque curve. See 350 dyno chart - mine is a 305.

Looks like I licked all the leaks I had .

I am installing the Monster transmission lockup switch next.

Then the 3 gages oil pressure , volts , temp . My factory dummy gages are all working fine in the meantime . I think I will just mount them on the console until I see some photos of a good place to put the three.

Ps I read guys had a lot of problems getting that oil pressure switch out above the oil filter ? I removed the 3 wire connector grabbed the metal body part with a huge pair of channel locks and seriously I had it out in 45 seconds..maybe I just got lucky ? So you guys may want to try that method instead of an oversized socket. The new part comes with thread sealer already on it . Here is a pic of the old sensor next to the new box.

jwfirebird

iTrader: (2)

the way the fuel normally works is the pcm primes then when the engine is running it reengages the relay, the oil circuit is redundant so you have one or the other to get you going. so now you dont have the redundancy because the ecm is not doing it anymore. that is fine really and it will shut down the fuel if the oil pressure drops.

as far as the sender it depends on your headers i think i have hedman long tubes and its dang near impossible to get to with those on. unless you have super tiny arms and hands

sootie007

Yes , it probably "re-engages" the relay due to the electronically controlled distributor feedback I bet once its running . When you swap out to a mechanical distributor you obviously lose that electronic distributor feedback loop . This car ran absolutely fine and started on the first crank every time with the original TBI and factory controlled distributor . So even though that pressure switch was bad in the original setup all that time the ECM didn't care and allowed fuel to flow based on distributor feedback .

But when you swap to a mechanical distributor you obviously lose that distributor feedback so then you need to rely solely on that oil pressure switch to keep the fuel pump going after prime.

Oil pressure switch removal with headers : Lucky me - I have the Summit shorties.

"unless you have super tiny arms and hands " ....why yes I do.

sootie007

So I took it for a spin ...it feels really soggy so it needs some definite tuning ..no sputtering ,backfires etc just down on "snap" .....good news is its starts with a flick of the key and idles great ......I have the initial at 8 I may take it to 12 tomorrow night and see if it is ok with that , lighter distributor advance springs are on order and then I will go after the carb vac sec spring....all this should wake it up. I will try to upload a video ...this ramjet cam sounds wimpy just like a stocker to me . It might get a tad more pop to it by increasing the initial we shall see tonight . I only rev it to 3800 rpm in the garage as it was late . In the 25 min I drove it - its running ice cold. I did have to adjust my Mallory FP regulator up from 4 lbs (Mallory out of the box setting in my system ) to 6 lbs.

One of the regulator ports with the pipe plug and sealant is seeping again .

I have an exhaust leak at the midpipe to cat delete pipe you can hear it ticking ....

jwfirebird

iTrader: (2)

i just used a bunch of the cheap white tape and it has been that way for like 10 years

sootie007

Yes I will do what you did at this point ..... maybe I will just put 2-3 wraps around it of Teflon tape on that seeping regulator port and see what happens. They said specifically not to use Teflon tape - oh well the Restoseal stuff didn't work on this port but did on the other port ?

sootie007

Engine compartment video ...

CAM P/N GM 14097395 246/256 .431/.451 109 ...cam used in RAMJET 350 350 HP 400TQ , HT383 RAMJET 340 HP 435 TQ

246 .431 256 .451 on 109LC

https://www.youtube.com/watch?v=Qy_B...ature=youtu.be

jwfirebird

iTrader: (2)

dont know, nobody ever told me not to and havent leaked a drop

sootie007

Tuning tonight I bumped the initial all the way to 13 degrees from 8 and I swapped the mechanical advance springs in the distributor to some light ones (red) . It doesn't sound AS lazy at idle like in the video- a subtle change. I took it for a spin and like I expected it did wake it up off idle and from the lower to mid range quite a bit . For the record that ebay HEI distributor had REALLY heavy springs in it . It pulls straight from idle all the way up slowly and cleanly never bucking etc . I couldn't really take it up to say 5500 rpm yet or tonight around my neighborhoods so that will have to wait for a stretch of road elsewhere.

Tomorrow I am going to put the light holley white short secondary spring in the Summit 600 VS carb and that should squeeze every last bit out of it and get things happening a little quicker. Again that should be the last bit of tuning to draw anything more out of it .

So just for the record for others what to expect on this combo it has 13 degrees initial with the 9.3 : 1 TBI heads ,Edelbrock EPS dual plane intake and Summit 600 VS carb. It has 18.5 -19" vacuum at idle in neutral , no pinging under load . I also went ahead and hooked full manifold vac to the distributor advance can. The Summit carb was dead on basically in its idle mixture adjustments according to the vac gage out of the box. I have it set to 750 rpm in neutral and it drops to around 600 in gear according to the factory tach.

Its still running ice cold water temp wise but the intake has an EGR channel under the carb that is NOT blocked off .

My impressions are probably tainted because I am coming from an aluminum headed Buick 462 with a 288 camshaft but to be honest with you I expected a little more torque feeling out of this combo. To be fair I cant give you all my final impressions until I get that secondary spring in there tomorrow night .....but so far this cam to me is not very impressive . Sure it starts great with VERY brief turn of the key , has a VERY stable idle but for a GMPP stick found in those hi torque crate motors I expected a little more torque feeling down low ....BUUUT lets wait until tomorrow night for the final verdict . I plan on taking it to a few roads tomorrow night to romp on it out of the hole etc to see what kind of ***** it has if any........ I know it seems like I am droning on in this thread but I just wanted to document each and every detail for people doing this very popular TBI to Carb swap down the road including the fine tuning at the end here .

jwfirebird

iTrader: (2)

the tbi 305 was meant to be a fuel efficient low rpm motor, not a performance engine. you cant really expect that much. 305's can make power but im not sure you are going to with those heads

Fast355

iTrader: (2)

Those heads will work just as well if not better than TPI or carb heads up through 4,500 rpm. That being said I am assuming the ebay hei provides 22* centrifical advance. 13* + 22* = 35* = way too much timing for swirl ports that pull best at 28-32°. With the q-jet fed tbi head 305 I built I welded the slots up to provide 18* total advance and ran 14* initial advance. The combination made very good torque in the 1980 C10 it went into.

I pulled a 416 head 305 TPI out of a 1985 Trans Am ( Basically a L69) and swapped it into an 84 El Camino. It runs 13* initial timing and 35* total by 3,200 rpm. CK rods on a G hanger and 7/8 air valve windup. Car has 2.43 gears and a stock stalled TH350. Has older rear exit exhaust manifolds that sweep down under the plugs and 2.25" piping to a dual in/single out cat and 2.5" pipe back to a magnaflow and a turndown. The TH200c and non functioninc computer carb hit the trash pile. The El Camino outruns a 3.08 geared 1978 Camaro that has a mid 80s 350 truck engine, edeljunk carb on a stock intake with 4 hoke adapter and long tube headers and TH350. A good running 305 can definately hold its own.

sootie007

Well I changed the VAC secondary spring to the light white short one in the Holley kit- weakest supposedly. It had the stout plain steel one in it stock.

It supposedly has got 2- 6.5 power valves in it stock...... I thought about putting two 9.5's in there but I really don't know if that will help at all seat of the pants on such a mild cam. Anybody have any thoughts on a power valve change in such a mild combo ?

Then it was too late to take it for a spin .....so the verdict / results will have to wait until tomorrow .....

I also fixed the exhaust leak - it was at my cat test pipe like I thought .

sootie007

Well I changed the secondary spring and it didn't make one bit of difference either way ?????? Then as an experiment I went the other way extreme - still not a single bit of change ??????? So somethings up here ...... after doing some experimentation I have come to the conclusion simply this carbs secondary power circuit isn't working correctly thus this thing is waaay down on power ...I didn't want to start taking it apart for fear of voiding the warranty - I am thinking the power valve or main circuit has an issue or obstruction but it feels like its running off two barrels when you mat it . The secondaries do appear to be opening however. I just know it simply is not fueling enough and climbing RPM wise at the rate it should. To its credit it idles phenominal , off idle "slow" tip in is great - but once you get to matting it to the floor this thing simply doesn't respond. It feels soggy like its only running off the primary circuit the whole time ever so slowly climbing and does this weird thing like its intermittently VERY briefly successfully pushing the correct fuel demanded in and out in and out - not stable bouncing in and out of fueling ...... I cheaped out and bought a rebuilt Summit carb here instead of the brand new one so I am guessing this is probably the reason it was returned in the first place. So I am returning this one tomorrow and a "NEW" one is on the way . Small cam and all this motor should feel much better than it is now.

Fast355

iTrader: (2)

Car is only going to feel so punchy with 2.73 gears. Not saying you don't have a carb issue too just reminding you of how horrible those gears are with a stock converter. I have a 5,800 lbs Nissan Titan that puts maybe 300 hp/370tq to the wheels. It has alot more jump off the line than my 6,200 lbs Express with 374 rwhp/368 rwtq. The Titan engine puts out its peak torque at 3,000 rpm. The Express at 4,900 rpm. The Express has a 2.48 first gear ratio and 3.73 axle ratio and a converter that stalls 2,250. The Titan has a 3.89 first gear and 3.36 axle ratio with a converter that stalls 2,700. Tall gears and tight converter make the engine feel sluggish and exagerate loss of off-idle torque.

sootie007

I hear you Fast ,....I drove the car for about 8 months on the weekends with the stock 170 horse TBI and it literally took off and pulled 20-25% harder than this thing currently when matted with the cam ...so this thing is L A ZZZZ Y its not gears .....Im 95% sure its carb ...advance is working fine and I did the bread tie trick on the secondary actuator rod etc .....I had a 283 about 25 yrs ago , factory cam , old non rebuilt 4 barrel etc that right now would leave this in the dust .......I really would have liked to pull it apart to try and fix it but like I said I was afraid of getting too deep - not being able to figure it out then not being able to return it ....This was my first time buying a rebuilt from Summit - I don't think I will bother buying a rebuilt again - just not worth the hassle in the end ... I am getting a brand new one this time ....that power circuit has issues...the bouncing in and out of fueling while climbing is an indicator too....we shall see in about a week.....will keep all advised and if it turns out I am wrong I will report back too with egg on my face lol.....

sootie007

So the new carb arrived, I had it on and tuned within an hr then off for a road test ,,,,this ones pulling a steady 19 inches at idle too .....so it pulls steadily now and doesn't feel like its going in and out of fueling as the rpms climb ...then I changed the vac secondary spring from the stock plain steel one to the short yellow one and I think that is as good as its going to get...tomorrow just for the hexx of it I will throw the short white one in there to see if it gains anything or finally bogs .

Cam impressions - this is all subjective but if you romp on it from a dead stop with the 2.73 gear you get a one wheel peel for about 2,5 to 3.0 seconds then it goes. The torque with this cam isn't noteworthy- this kind of shocks me because I intentionally went this small to up the torque and this grind from GMPP has unreal torque in the 350 and 383 crate motors 435 ft lbs in the 383 ..it doesn't pin you back in the seat at any time etc and you never feel the cam turn on into any kind of power band at all ....just steadily climbing forever YAWN - I took it up to 5200 tonight . Looking back immediately right off idle it does not feel to me any more powerfull AT ALL than the stock TBI peanut setup...then from 2k-4k it feels like is pulling a little harder and was still climbing up to 5200 ....Now my last motor was a 10:1 462 Buick with a 288 camshaft so maybe I am a little spoiled but this ramjet cam IMO is totally tame, has no real noticeable idle tone or chop ,would idle great with accessories on a.c. etc , doesn't really have a pronounced power band and steadily climbs up to 5200 at least .......I am going to say this is a good cam for a daily driver and really needs a 3 series gear to get out of its way for any fun factor. Maybe this same stick in a 305 or 350 feels totally different with some decent heads but if your looking for any real performance gains with the stock TBI heads and 2.73 I don't think this stick is a good match....for a daily driver that does NO track duty it would be a GREAT cam for that with a little stress little performance gain........FWIW .

I have an 89 L98 cam new in the box but I don't think I would even bother swapping it in since this ramjet cam was geared for torque and was disappointing so the L98 probably isn't going to be any better .

I would be interested to see what effect dropping this ramjet in at say +4 or +6 would do to it ? More torque possibly - might put it right where it needs to be in a 9.3 :1 motor ? Who knows .....if I get some free time I may put it in advanced just to see.

graysmoke

You need gears. I went from 2.73 to 3.42 posi and with no mods it is a different car out the hole.

sootie007

So I went to put in a mechanical oil gage tonight using the port on top of the block near the distributor. I was greeted by a pipe plug that was mangled to death by the p.o. Arrrgh . So after trying a few undersized sockets , needle nose vice grips etc. with no luck I had to bring out the heavy artillery. I welded - yes welded a 9/16 nut over the stump of a plug and on about the 5th nut attempt I finally got it out. 2:45 hrs on a simple pipe plug. Every time I welded each nut on the stump it didn't "take " to the pipe plug or unwelded itself from the stump as soon as I got a socket on it and started twisting-torqueing it ......it was an exercise in perceverence but I finally won lol. The trick to get the weld to stick to the stump solid was to take the nut over to my bench grinder and rough up the face of the nut with the grinding stone as opposed to hitting it with the wire brush wheel to remove the oxidation off it before welding it like I did every time before .....I guess the brush made it too smooth and I couldn't get a good weld on it but roughing it up prepped it properly. Here is a pic of the infamous 2hr and 45 minute plug lol......

Fast355

iTrader: (2)

In a 9.4:1 305 with vortec heads and a MPFI intake that has roughly 10" long runners the 395 cam makes peak torque at 3,800 rpm and peak hp at 4,800 rpm. That being said I had a .030" over flat top piston 305 with a 203/210* LT4 cam with a set of 187 TBI heads on it. Stock long tube runner TPI setup. Doug Thorley Tri-Y headers. All stuffed into the engine compartment of my 1983 G20 van. Stock stalled 700r4 with 3.08s out back. It would damn near spin 275/60R15s all the way through first gear from a stop and that was on a stock 305 TPI chip with the VATS turned off.

KILLemALL

iTrader: (3)

Do you have any insight as to where the torque is going,or are you just saying nah nah nah boo boo?

jwfirebird

iTrader: (2)

if i had to take a WAG, i would say timing, idle timing on most bigger cammed engines is 18-20, thats where mine feels the strongest out of the hole

Fast355

iTrader: (2)

I bet the engine lost 10% of its torque going to a carb from TBI but he doesn't want a computer. TPI probably makes 10% higher peak torque than a TBI and probably 15% better than a carb. That being said TBI and Vortec heads are not much different in the low-midrange torque department with TBI actually being slightly better. That marine engine making 302 ft/lbs probably only makes 270 ft/lbs with a carb. The carbureted 305s that I have driven with a square bore carb do not make as much torque as a well tuned Q-Jet. Those tiny primaries just give better response and atomization which helps throttle response and torque.

Also in my experience the TBI heads like a very weird timing advance curve. Lots of initial advance (18-20* BTDC) and a very short, quick centrifical curve (10-12* for 28-32* total) that is full in by 2,600-2,700 rpm. They don't like much vacuum advance either. 10* @ 10 in/hg starting with 0* at 5 in/h will do it. However most street engines do not like starting with that much timing, so usually the initial timing has to be backed down to 12-14* to allow a heat soaked engine to start. To get to 28-32* you need about 18* mechanical advance. A standard HEI with 22* centrifical advance will give you 34-36* total timing which is too much. When you retard back to 32* total advance you end up with 10* initial advance and off-idle performance suffers. With a mechanical advance setup it is also very difficult to get the weights and springs to allow the advance to ramp up that quickly, yet still return to base timing at idle. Mechanical limitations of a non computerized carburetor setup are why you end up losing some torque compared to a TBI.

sootie007

Ok I am getting no perceived kickback AT ALL at start up with 13 initial so I think it can definitely take more initial. You guys are saying this cam is "bigger" and most need 18-20 degrees. On "wilder" cam setups in my past experiences I have found that to be true also but consider this cam a wimp - more on the little side . I will give it a shot but I am thinking the exhaust temps are going to run waaay hot at idle - aka glowing orange headers with that much initial timing on this "little" cam. I will also put a bigger timing limit bushing in the dist. or weld it. I am getting a good quick advance curve with those two red springs in there AND they are returning to idle as they should. As you know you can hear rpm wise when guys advance weights and springs aren't returning to idle rpms as at a traffic light -they will be idling at 1200 rpm because the advance springs are sprung out and haven't been able to overcome the weights. As the car sits there awhile the idle slowly comes down as the springs finally win the battle over the advance weights. Mine is NOT doing this with the red set in there - so I have that set perfect .

These are freebie tweaks - lets see what happens here and maybe it will wake it up like I thought in my head this should run and apparently others are thinking here too . So I will shoot for 18* - 20* initial , 12 * -10 * centrifugal all in by 2700.

That would be an increase of 5-7 * initial (huge) over what I have now...so if it can take that much initial - yet still be startable when hot , not ping , it should definitely have ALOT more snap to it.

Thanks for the input gurus ...lets see what happens and to help guys down the road tuning with this exact combo.

Fast355

iTrader: (2)

I have the cranking timing in my cammed Vortec 350 Express set at 16 or 18* I forget which. The least amount of advance the Express sees at wide open throttle is 16* and it does not spark knock even with a stock stalled 4L80E and only 3.73 gears pulling 6,200 lbs. If starting becomes a problem, the smaller Vortec/LT1 permanant magnet starters are much more powerful than the older designs. Idle timing on the Express bounces around between 28 and 34*, its not perfectly stable because the PCM uses spark advance variation to help control the idle speed.

sootie007

Sounds good - based on your experience then it shouldn't have any issues at all with that much initial and then some ..... hexx at 9.3 :1 its sounding like running 28-32 locked out timing might even be possible with a hi torque starter on this mild setup. I will tweak it tonight and let you guys know . You know how it is usually - 5-7 more degrees initial is huge in off idle performance and should be very noticeable. I noticed at idle when I first started this up it just sounds laaazy with no "pop" felt at the pipes - which would normally indicate to me it can take more initial...but I was afraid of burning up the header paint ....guess I should have listened to my gut ....will keep all advised ---- thanks again for your very respected input.

86LG4Bird

iTrader: (1)

sootie, Advancing the timing will not raise your exhaust temps at idle. RETARDED timing does that.
You made me chuckle when I read this: 'You guys are saying this cam is "bigger" ...' I'll give you this: At least it's not tiny for a mild 305

Just wanted to add this: Don't get hung up on the timing "number". I've found enough instances where going by the marks is simply NOT what the engine wants. Experiment and don't worry about the number you end up at.
People were telling me I was running too much with the original LG4/peanut cam and L69 chip at 12 degrees initial. But.....I just had to disregard that cautionary advice when, on 87 octane fuel, it never pinged at that setting and always lost performance when I backed it off.
What octane fuel are you running while you're doing this tuning?
If you haven't already, you might want to use 87 octane to find that MINIMUM base setting where it's just on the verge of spark knock when lugging it or at hot startup, then go with 91 or 93 and adjust up from there for performance. That may sound silly to some, but it's a sanity check to make sure your timing reference isn't keeping you totally outside the true tuning window. I see no risk in running 87 in your engine temporarily; it should be just as octane-tolerant as a stock 305.
With the Vortec that's in the '86 now, after finding the best power timing setting at the track with 93 octane, it's happily running on 87 with no detonation whatsoever in daily driving.

Fast355

iTrader: (2)

What are you running for timing in that car anyway?? LG4 or L69 chip? Trying to help a local guy with a vortec head 355 in his CCC car. If you are still running the LG4 chip, I figure you are up from stock 6* to 12-14* BTDC. Which puts you about 30-32* total above 3,600 and 14* at 600 rpm at 0 vacuum. The LG4 runs 22* of WOT total timing in the chip and the L69 runs 28*. Suggested 8-10* and the L69 chip for him for 30-32* total timing and 12-14* @ 600. L69 has the mixture control solenoid table programmed a little higher than the LG4 in open loop.

86LG4Bird

iTrader: (1)

Heh heh ..........further to my point about disregarding the "number" ......
I DON'T KNOW!

I've run the L69 chip in that car for a long time, even with the old LG4 motor. As I said above (edited to point out it had the L69 chip), I'm a bit skeptical of even the factory timing reference based on the fact that it indicated 12 degrees initial after I made it "happy". And yes, that was with the ESC disconnected.

The timing cover on this current engine doesn't have a timing pointer; just an El-Marko stripe per my eyeball when I assembled it. I had guessed it to be about 12 degrees for first startup, but considering how much I've advanced it beyond that for best trap mph, I have to assume my "eyeball" calibration was a bit off!
I actually believe I'm about 18 degrees initial, but....... I don't really know and I don't really care

One thing about that L69 chip I don't like: locks the TC at a ridiculously low mph. It causes some roughness/jerking during deceleration and "barely-throttle" cruise in the 25-40 mph range. As soon as I lean into the throttle at all, it seems to get out of its lean condition and is totally smooth. Your comment "L69 has the mixture control solenoid table programmed a little higher than the LG4 in open loop" reminded me of this. I need to force it to stay slightly richer in the 0 to 5% TPS range. Any ideas? Pretty sure my issue is in closed loop only.

Fast355

iTrader: (2)

Fair enough!!! Reminds me of how I used to set the timing. I would pull the knock sensor wire. Then pulled the dog house off, loosened the distributor slightly, hammered the throttle on an empty road, reached over and adjusted the timing until she started to ping then backed off.

I have actually turned the knock sensor off on the Express and pulled the doghouse to listen to the engine at WOT as well. It gets pretty hot and loud and any detonation is instantly noticeable.

In the top left of the picture you actually see the sissy pedal, lol.

Fast355

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The duty cycle table is really an open loop thing. The 02 sensor does more with the closed loop. As for your lean off-idle and torque converter locking early, I would atleast check and attempt to adjust the TPS voltage. I would bump the voltage as high as specification will allow. That way the slightest rise cause a TPS % rise. Also remember off idle you are also mostly using the idle circuit of the carb and those have idle feed restrictors in most applications that are likely too small for your healthier L31.

86LG4Bird

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I had that exact thought about biasing the TPS base mV reading higher and was about to add that when I saw your last post ring in
Do you think it would affect the MCS (needle height in the jets) at all at such a low TPS %? I've never seen the tables to know where TPS starts to affect commanded AFR.

Yes, I agree the idle feed is inadequate for the lower vacuum of the ZZ3 cam. I have the baseplate screws backed all the way out.

I wondered if adjusting the lean stop of the MCS would have any effect at all; I doubt it since it's operating on the idle circuit.

sootie007

Thanks for chiming in Bird....believe me I know this is a tiny cam. ...I have run up to a 292 cam before so I am a little familiar with basic tuning challenges and crutches as you go bigger.

I was just afraid this cam being so small might lean burn the paint right off the headers with that much initial - obviously many are pointing out I am totally wrong on that here - no problem .

"just wanted to add this: Don't get hung up on the timing "number". Im with you on that - just like carbs its what the INDIVIDUAL engine / combo wants and more importantly responds to - not what everyone tells you (except here lol) . I respect you guys opinions immensely and thanks for chiming in ....I am expecting a big improvement with these timing changes.

I am going to run locked timing at 30 and see what happens. I am going to fab one of those little strips that goes across the timing spring perches and timing plate tonight - to lock it .

I am running 93 octane and haven't heard a single spark knock out of this thing yet when test driving it .....like I noticed it starts waaay too easy and sounded lazy from the start in the video - even with 13 initial -- it all points to wanting more timing ......

Will keep all advised on results.

Fast355

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If you want we can start a new post about this and I can try to dig up the 8079 hack I had back in the day or the 830' hack for the 307 olds I had hanging around.

Considering the mixture control rods actually completely block the jets and all fuel entering the primary side goes through the main jets. I think that adjusting the lean stop limit would work very similarly to adjusting the APT in the older Q-Jets. Its been a few years but at one point I had a 403 swapped in an 88 Cadillac that had the 307 CCC setup on it. Its been a while since I messed with it, but I seem to remember picking up both a 1981 L81 Corvette carb and a 1988 9C1 350 carb. Both of which had different size jets than the 307. I used the largest CCC Q-Jet primary jets I could get my hand on. Also keep in mind that your off-idle problem could also be the idle air bleeds being too small, making you have to open your throttle plates further than necessary, which affects the off-idle transition port vs throttle plate position. As different as the CCC Q-Jets are, they are still a Q-Jet under the mixture control solenoid.

http://www.circletrack.com/enginetec...rburetor_tips/

http://www.wallaceracing.com/qjetidle.php

86LG4Bird

iTrader: (1)

You're sensing my own conscience! I was already feeling guilty about my hijack. I will do that. Sorry about that, sootie

sootie007

No prob its all good.....we are here for one reason to help each other ....

splitface454

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I might have some...

I had the same problem with my swirl port heads on my carbed 355...no torque at all. Inline with what Fast355 has said I bumped my initial timing to 20* and a short 6* advance for 26* all in by 3000rpm. Anything OVER 26* total I lose all my power up top. Anything UNDER 20* initial and all my bottom end power. At 26* 6400rpm is not a problem 28* and it wont go over 5500rpm.

Keep in mind I do have quite a bit more cam .234/.244 .488/.510 114LC

sootie007

Interesting ...did you ever consider running locked timing at 26 ? Very interesting how narrow - sensitive that advance channel is in your setup (20 init -26 total ) ...... I suppose there is some weird issue with the swirl ports that induces this. I have never heard of a setup being so timing sensitive - but I believe you and fast355. Then again these are weird heads every one poo poos and most toss them and don't want to run them - except for guys like fast, bird and yourself etc. who know what they need to run properly in a build at this lower HP level .

Whats weird is the initial timing setting for this cam on the 350 RAMJET CRATE ENGINE is only 10 degrees- BUT those are modern Vortecs on that engine , F.I. and a computer running the show - but wow to need +10 * on top of that 10* initial timing setting is surprising. I wonder if guys running that RAMJET engine ever get rid of the computer / FI , switch it to carb then immediately have to bump the timing +10 * too 20* also in that vortec headed combo ?

So I am assuming you have 284 294 488 510 duration on that cam ?

This one is only 246 256 431 451 lol.

Fast355

iTrader: (2)

The Ramjet distributor setting is only the base timing. The timing table at WOT on the ramjet starts at 12 or 14* @ 600 rpm depending on MEFI 3 or 4 and is over 20* before 2,000 rpm. Maxes out at 32* below 4,000 rpm IIRC. I have the spark map somewhere on my tuning laptop.

splitface454

iTrader: (1)

I haven't tried locked timing. I struggled getting this thing to run right. I tried running 28 to 32 and was just never impressed with the power no matter what I did until I got the total timing figured out for my setup.

Fast355

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IIRC Dewey316 was running about 20* initial and 29* total on his mildly cammed L03 with the single plane weiand 7525 on it. Car was putting down around 220 hp at the tire and I want to say about 300 tq to the tire through a 5spd.

Fast355

iTrader: (2)

Also found another post from when Sean ran his nearly stock TBI 305 on the dyno. Gained 15 ft/lbs and 15 hp on 87 octane advancing the base timing to 6* from 0* and in the process increasing his total timing from 25* to 31*. He said it was knock free at 6* but knocked under load at 8*, even with 91 octane. Falls right in my 28-32* range I have used for years with these TBI heads.

https://www.thirdgen.org/forums/tbi/...ed-w-chip.html

Fast355

iTrader: (2)

Are you running the 187 heads on the 355 or a set of 193s?? I do remember one of the TBI 305s I tuned a few years ago only liking something like 27* of timing.

Ghettobird52

On the 187 heads, what do you think maximum advance should be? Im runnign 28* right now (2* advanced).