billybob6110

the current cam i have is not really what im looking for. im on the market for a new cam to help "level" out my mismatched combo. anyone with input please help! my goal is a 12.99 and lower street car. thank you in advance!
350 0.30 over- 55235 APRROX MILES
210cc aluminum heads 2.02/1.60 valves- PRO COMP.
Roller rocker arms-3/8 1.5 RATIO
Edelbrock cam .488/510 duration is 230/240-FLAT TAPPET
Air gap intake-MATCHED PORTS
Msd ignirion
14* base timing
Hooker headers to true duals- HOOKER HEADERS 25/8 PRIMES TO 3 INCH
Stripped interior of anything usless
Procar racing seats

7.5 TEN BOLT WITH 28 SPLINE MOSER AXLES C CLIP ELIMINATORS
3.73 gears- DETROIT LOCKER
275/15 rear drag radials
Turbo 350 trans
2800 stall-
STOCK SUSPENSION WITH FRONT SWAY BAR REMOVED
UNSURE COMPRESSION MAYB 9.8-10.1ISH

midias

Got a part number for that cam?

Also ditch the pro comp heads.

billybob6110

edl-7102
ditching heads arent an option at the moment. gotta work with what i got

midias

I am not a big fan of that cam. I have seen it make some good power but on other engines I have seen it fail miserable.

With the full edelbrock kit it makes about 400hp at the flywheel.

I will have to think about a good cam for those heads. They don't flow much until they get over 500 lift and even then they flow poor for 210CC heads.

Orr89RocZ

iTrader: (20)

Can you swing a hyd roller conversion

billybob6110

a roller conversion wouldnt fit my budget right now, i just cant get vacuum or power until about 3000rpm then it really kicks ***

midias

Yea unfortunately you will need to stick with a higher RPM cam. Those heads only flow about 230CFM at 500 lift and with 210cc chambers that will be rough. So you will be limited by how fast you think you can spin your engine.

http://www.store.procompelectronics....oduct_id=37062


With your build what is your max RPM?

bwiencek

Really need to know what the compression is to pick a good cam. If you're running stock pistons or worse yet "rebuilder's" pistons you're going to be WAY down from that compression number - which is going to kill power potential

With those heads on a 'small' 355" engine it's going to take a high lift cam with some upper RPM's to get any respectable power out of them - which is what I think you're finding out...

The head ports are way too big for a (primarily) lower rpm street engine as with any large runner head the low RPM port velocity suffers and flow suffers.

If ditching the heads aren't an option - then how about building more compression with a small dome piston then running a 3800-4500 stall converter and a good solid flat tappet cam (something like a Lunati 30120919 a Doug Herbert HERCC5R, or one of the circle track grinds actually work well - the summit CT-109 is actually a pretty decent inexpensive cam if you can't run a solid roller...)

Orr89RocZ

iTrader: (20)

That cam is fairly large for your motor. Good for high rpm like you said but below 3000 its gonna be rough. It has lazy lobes so there goes your low speed vacuum and torque/driveability

Given your converter and goals, i would step down to a comp xe or lunati voodoo series around 268-270 adv duration which will give 224-227 at .050. Order on a 108-110 lsa

It will give you good vacuum, and work with those heads and converter. Thats the largest cam i would run in that setup. It will turn 6200 rpms fairly easily. Anything more than that you would want a 276 or so cam and 3500+ stall to run best

Heads have a big cc port but the valve size is small so it should still give decent low and mid range just need to cam it right

midias

This might work out for him but I am thinking he will want to get over 500 lift with those heads.

http://www.summitracing.com/parts/cc...make/chevrolet

billybob6110

max is 6500

billybob6110

its got the summit flat top pistons currently, but when i did the heads they had the sunglass look on the pistons which makes me think the guy who built the motor wasnt truley honest on what it has.

billybob6110

with that cam do i got to buy lifters to match as well as pushrods?

midias

Any new flat tappet cam will require new lifters. Pushrods should remain the same if the lifters are the same height.

Orr89RocZ

iTrader: (20)

Always check pushrod length and geometry. Should be same if same base circle but never know.

If you can get up over .500" lift it will help make more power up top but its harder to get up that high with most flat tappets. Need 1.6-1.65 rockers

billybob6110

ok cool. now if i replace that cam with the comp cam shown in the post would i be in my range for 12s? say if i got a higher stall 3200-3500 with the current cam would i be in the 12s? just trying to see what "makes sense" rather then rob peter to pay paul

midias

If he plans on spinning to 6500 think the XE284 would be a good choice?

http://www.compcams.com/Company/CC/c...x?csid=88&sb=2



Or stick with something a little smaller like the 274?

http://www.compcams.com/Company/CC/c...x?csid=87&sb=2

Orr89RocZ

iTrader: (20)

274 for 6500 max but i'd still consider the next size down if you want to keep 2800 stall and have much better street manors

268xe plus the rest of that combo will run mid 12's easily.

Car sounds light and on good tires with a th350... Should launch solid. Keep the low stall for street driving and the smaller cam. Compression isnt high enough to run much more than 268-274 deg cams. 350's start to get alittle lazy with 230 deg cams at .050, much like how ls1 motors are. They need 3600-4000 stall to really move

midias

274 should work for a 2800 stall, it will work down to 2200.

Orr89RocZ

iTrader: (20)

You can drive it on stock stall if your tune is good but it will be lazy. Been there done that . Needs alot of stall to really 60' well at the track

midias

I am glad I don't have to deal with auto BS on mine

With a manual I find that trans perfectly streetable. Now I just need to get rid of my locking rear and get a real posi.

billybob6110

thanks for the help guys. so im going to go with the 268xe cam do you have apartnumber for that by chance. im going to run and see what this cam does and over winter/fall im gna yank the cam and put in new one. cant wait to hit 12s, then ill be content.........for now.

midias

I believe you want this

http://www.compcams.com/Company/CC/c...x?csid=86&sb=2

Orr89RocZ

iTrader: (20)

Have you ran the car with the current cam? It should be pretty quick if tuned well just lazy off the line due to low stall. 268 will help that or up the converter

billybob6110

havent ran it yet i never raced and kind of embarassed to go and test if it runs like a 14 or something which it shouldnt..

Orr89RocZ

iTrader: (20)

Do you like how it currently idles and drives?

billybob6110

ya but the brakes really suck after awhile. the idles not real choppy i have the idle speed up to bout 900rpm, and it runs great just heard bad reviews with the cam and to switch it out

billybob6110

also totally off subject could my tranny shifting to soon cause a horsepower lose feel? if i cruise itll shift all through the gears by 45mph. when wot it shifts quick. not sure if i should change the governor springs or leave her be

Orr89RocZ

iTrader: (20)

Well the 268 and 274 should do alot better as far as idle and vacuum go, with the 268 providing the most. Both are capable of 12's. 274 fits the head siZe better but converter would be better suited to the smaller cam unless you restalled it. Probably not needed for a street driver and a 12 sec pass. A 274 cam on 2800 stall with good timing curve should leave hard enough to get 12's.

I'd still try to get a baseline where you are at currently. Dont be embarrassed if it is a turd. It happens. You are working in a new setup so it takes time.

Cant go wrong with either cam 268-274 if you swap them out, both i consider better than what you have. 1.6 rockers and proper springs for the cam should be considered too. You will get your goal in good air.

billybob6110

thanks man ill swap cam out just for the little better umph

DeltaElite121

I've got a brand new XE274, actually. Swapped it for a solid flat tappet.. I'm asking $100+ shipping for the cam and lifters. 0 miles on them. PM me if you want it, heh.

billybob6110

whats shipping to alliance ohio 44601?

billybob6110

ok ran the car last night and got some really **** poor results.
reaction- .4829
60 ft- 1.9999
330 ft- 6.0132
1/8 et-.93281
1/8 mph- 74.39
1000ft- 12.16
100 mph- 85.91
14.5797 1/4 et
90.65- 1/4 mph
is this the result of the stupid cam? it has no "launch power at all" but getting in the power band for the cam is really noticeable. also im getting some oil out the spark plug holes, would pistons leaking cause an issue in performance also?

Orr89RocZ

iTrader: (20)

Was that the current cam 230/244 in the original post?

If you are feeling the motor come into its power band hard then you dont have enough converter. The rpm you feel the motor really start to pull hard you want the converter to be withing a few hundred rpm of that point


Also that mph is way low. Sounds like motor isnt making any power and is really hurting somewhere. Has any carb tuning been done?

midias

Ouch, that is about on par with my winter toyota. Either way not every pass is a keeper.

There are 3 things holding you back.

Your stall, cam and heads

Your cam and heads are not designed for low RPM performance. Your heads flow similar numbers to vortec heads but not nearly as well down low and their chambers are huge 210cc vs 170cc. Big ports and poor flow = bad low end.

So you have heads that want lots of lift and RPMs, a stock stall and a cam not really matched for either.

billybob6110

I have the holley street avenger carb. its all stock with a 31 squirter and stock jetting. the accel pump is adjusted correctly and I got the orange cam in the 1 position. I have no idea about holleys so it might be the issue

billybob6110

I have a 2800 stall convertor in it now. stating that the heads want more lift would I be better with one of the cam previously stated or go with a higher cam lift, 3500 stall, and keep current heads? im going to be pulling the motor due to the pistons not sealing causing blow by.

1gary

If your going to address the pistons issue,might be a prime time to go 383 stroker.Well really it would be 388 with a bigger fresh bore.That way you could better use the heads you own and cam it accordingly.
I do think what you found out is in part is in line with what I have been telling guys for yrs.These engines being a air pump,is a systems approach where matched parts is critical.That the days of slam parts and go are long gone.Well really that and the fact of blow by which is really hurting you cause not having a solid bottom end.

Another way of looking at this is to buy a L31 block and build up a hydro roller 388.Sell off your short block to off set the extras costs.
In either case shoot for a target quench of .040 to .035.That does help a ton to run pump gas and will wake up your engine's build.

DeltaElite121

You've got a host of issues going on.. You can replace parts ALL day long and waste cash doing it if you're not careful. Your current cam and converter can run halfway decent times as long as everything else is in order.. The problem is those heads stumble ALL the way up to their good/usable range, and the port velocity (and your current compression in conjunction) are absolutely killing you.

I'm on the fence as to what to tell you since you're on a seemingly tight budget. What kind of cash are you working with? The last thing you want is replacing parts where it's not needed.

Orr89RocZ

iTrader: (20)

The heads should be fine for a 12 sec goal. Just need to match the rest of the drivetrain to it and if you have ring seal issues, no heads cam combo will work well. Fix that, freshen it up, and tune the thing

billybob6110

absolutely agree with you on that. I really cant afford to purchase new heads at the moment, but I am going to by a rebuild kit and rebuild the motor. the fact that I thought it was fuel fouling out my plugs, actually turned out to be oil, and to me a lot of it. it covers the heads below the plugs, so I know that's a issue. so all im asking is im keeping the current heads is to point me in the right direction with a cam and possibly a convertor (everyone has helped me ALOT so far and I appreciate it.) so if the cams listed above will work ill purchase on of those to, and a higher stall.

DeltaElite121

That's obviously a given, I am merely coming from the same angle as Gary in the "since its still apart..." way of looking at it. The question really lies in how much he is wanting to throw down on the project. Fixing the obvious problem present is the first step (and arguably where a huge chunk of the problem is along with the tune is my guess), but I still think those heads are holding him back from what he COULD be doing, particularly in mid lift numbers. No cam will fix that.

DeltaElite121

Fix the motor issue first that way you push all your critical funds in one spot as opposed to spreading it out and not isolating your changes in one area at a time.. Run it with the current setup and see how it rolls once everything is fixed. What type of converter is it?

billybob6110

its a flashed convertor from Vickers transmissions in alliance ohio. he said it was a 2800 stall but when I got to launch at 2500 it starts to slide the car forward while holding brakes. so I think its a 2500 stall? I hate to repair the motor keep current cam if it needs switched and have to pull the motor apart again to do the cam. wouldn't it be "wise" to change cam while motors out?

DeltaElite121

Well, yes and no. You'll need another converter if you go much bigger on camshaft profile. If youre going to buy another converter, you absolutely should NOT buy another 'shelf' converter.. You've already done that once. which means: $800-1200 for a torque converter. save your cash and do it right, or just hold onto your money. That cam is more than capable of reaching your goals assuming everything else is working as it should. I personally wouldn't change the cam if you're on a massively tight budget, but that's just my opinion. If you plan on buying a new converter then yes, now would be a good time to do it.

There's a lot of stuff you can run cheap on, but a torque converter should never fall under that category. Do the other stuff RIGHT so you're not wasting money doing a juggling act.

billybob6110

true. but leaking piston rings can cause that much of a performance loss? im new to building motors so if I should "stupid" that's why. so basically saying I should fix the pistons and leave everything else alone and tune the motor and I should have my 12s motor? or am I missing the concept of everything?

DeltaElite121

Some of the most seemingly minor details often have the greatest impact on how anything mechanical operates. It's not a stupid question; it's a very valid one.

What's your budget? If you're going to tear into the bottom end like you should, now is your perfect excuse to build a stroker if you've been looking to do that. Do you NEED to build a stroker? Nope, you don't.. and certainly not to hit 12's. Is it one of those "I should've _______ while the motor was out of the car" questions? Yeah, probably.

It all comes down to how much time and money you've got.

billybob6110

whats all intitled to make it a stroker? a 400 crank? bore out? and how much does that run to make a stroker I kinda wana stay around 2000 tops

Orr89RocZ

iTrader: (20)

I would have the bore rehoned if possible with new rings. Break in properly and double check everything from assembly. Make sure you adjust lifter preload properly, and have proper pushrod length.

If you were going to spend money i'd do a hyd roller conversion with new valvesprings. 350 is plenty for 12's, you just need to find out why the parts you have are not making power. ET is one thing but mph is low and thats not a cam and converter issue by themselves. I am not sure bad ring seal would kill 100-150 hp you are missing either. Something isnt right

billybob6110

im not sure either, like I said its a snail off line then it picks up power real fast but never goes over 4500-5000 rpm on the track. I dunno if something is wrong with cam or what just sucks putting money into a motor and expecting one thing and getting another