Amillionoh7

iTrader: (1)

Specs: 92 RS 305 700r4
:Lunati CAM 480 lift 300 duration w/fuel pump lobe
:Edel performer intake
:flowtech header
:Holley 750hp series carb w/vac 2nd's
:Ebay distributor
:gm mechanical fuel pump w/ dorman pushrod

Amillionoh7

iTrader: (1)

still need a y-pipe, and waiting on my valve covers to show up

SouthSide2

Your so right there... do you have a Throttle plan?

SouthSide2

I'm so far away from putting mine together. any thing you may add would be a plus. I may have some in put how ever I'm not at your point in the build'

midias

305 with a 300 duration cam is going to be a bit rough on the street. I could be wrong do you have a part number?

There are some other things that seem mis matched but they are based on my guess about the cam.

1. Cam with power band ~2500-6500?

2. The carb is VERY big for a 305 but may give decent performance in the top end. Did you keep it roller?

3. The performer manifold is a near stock copy and not designed to work over 5500 rpm. It will choke your combo.

4. Flotek headers will also choke the exhaust in the top end. They are probably the worst design and their Y pipe might be the best thing I have ever taken off a third gen. I just replaced a set on my friends TA with some decent headers and the difference was amazing and he has a low reving engine.

5. Are you using stock heads?

6. Stock heads are going to crush your combos chance of making any real power.

Amillionoh7

iTrader: (1)

Ok quick update: yes my manifold and exhaust are terrible. but i am building a 383 so that is why i have that cam and carb. the car has been setting for a year and i got impatient and just slaped the stuff in the 305 for now

Amillionoh7

iTrader: (1)

I can not find the cam anymore but its a lunati bracket master cam

midias

I cannot see any part of this combo working well. You are also at the max lift for stock heads with a 480 cam. I would get another cam and save that one for the 383. Then you may be able to tune the carb to run well. Search craigslist if you are getting impatient.

I looked at a few of those and I just cannot imagine them idling or running well in your setup.

Amillionoh7

iTrader: (1)

I understand everyone's concern but its already together and im not taking it apart again. The car is just a toy and wont be driven much so until I get my 383 finished this will be fine.

jwfirebird

iTrader: (2)

i think it will be fine. might be in the 50's on the primaries, the originals on mine were like 70 i think and i have a built 350, i ended up low 60's i think. dont know about the vs adjustments i dont have one but i have read its good for an over carb situation because it doesnt flow more than it needs. i would hope you have a bigger filter in mind for the 383 as well.

Amillionoh7

iTrader: (1)

Yea. I am trying to decide on a hood rite now to fit a larger filter. I like the 4" cowl but that's what everyone uses. would like something different

Amillionoh7

iTrader: (1)

I am running 74 on the primary now but yes probably will have to lower it

Amillionoh7

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MISTAKE: The cam is 300 duration advertised but only 246 at.50 so not as bad as everyone thinks

midias

What is the part number?

Amillionoh7

iTrader: (1)

I can not find it summit does not sell it anymore. I got it off craigslist last year. I will post a pic of the cam card when I get home

Night rider327

iTrader: (13)

246 @.050 on a stock/mild low compression 305 is very bad. WAY too much cam and carb.

Heck my cam is 249/252@.050 on a almost 10.5:1 compression 355 with Brodix heads, etc and it's boarding on too large. This is an engine that is only used in the 3500-7500 rpm range too with a 3500 stall converter and 3.89 gears

In a mild 305 you really shouldn't run anything over about 226, maybe 228 @.050.

Myself I would use a 212/224 to 216/228 @ .050 max. and a 500-600 cfm carb.

Good luck with your project, but do not expect it to idle good, or drive good. It's gonna be real lazy under 3500 rpm, then run out of breath at 5500-5800 rpm.
You will need to trow lots of timing at it to get it to idle half way decent. It's gonna want so much timing the starter will kick back and drag.

Night rider327

iTrader: (13)

Oh btw that would be part # 10120412... That's the only bracketmaster 300* adv, 246* @.050" cam. Lift is .515", not .480"

Advertised Duration (Int/Exh): 300/300
Duration @ .050 (Int/Exh): 246/246
Gross Valve Lift (Int/Exh): .515/.515
LSA/ICL: 108/104
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 2500-6500
Includes: Cam Only

#10120412LK for cam and lifters

midias

Good luck, please change your valve spring they will not support the lift. Should be a very interesting combo

RamIt

Gonna sound good.
Just dont try to race a Prius. You will get your a$$ handed to ya.

InfernalVortex

iTrader: (4)

You've made it clear you dont really care... but Im pretty sure most of us were thinking that was 300adv and some amount less at .050", but most of your idle characteristics and powerband characteristics are determined by total duration. The @.050 number is more relevant to how much power it will make. Thats a really big cam for a 350, pretty big for a 383 but probably doable with the right combo. In a 305 it's going to be extremely, extremely huge.

Amillionoh7

iTrader: (1)

Exactly what i figured too. This whole setup was just to see what happens. FOR FUN. I had all the parts laying around for another build so what the heck why not.

Damon

I sure hope you opened up retainer-to-guide clearance on those heads AND installed a set of springs that can handle that cam. If not, you are likely to bend every pushrod in the thing the first time you crank it over on the starter.

I'm not so concerned that you're going to lose a race to a Prius as I am that it won't even make it out of the garage under its own power.

You can build a Frankenstein and say "whatever, it's just for fun" but you can't blow off things like valve lifts that will literally make the retainers slam into the guides/seals at max lift. Parts will break. Very quickly.

midias

I have asked about valve lift a few times. No response. He is also running a flat tapper cam so there is a good chance that the lobes will be wiped as soon as he starts and that will be added to the ruined parts list. Other than that about the worst thing that can happen is a valve retainer breaks off and a valve blows out the piston and cylinder wall.

Will look kind of like this

Night rider327

iTrader: (13)

Also have to worry about piston to valve clearance.

Duration and LSA has more to do with P2V than total lift and that cam is getting to the point where it will not have enough p2v clearance with anything other than deep valve relief pistons.

Like with my cam, it's a tad bigger than the OP's, I had a set of common 6cc 4 vr flat tops.. I didn't have enough p2v clearance, so I had to either flycut those or replace them. I replaced them with 2 vr 5.5cc flat tops.. So think about that.. 0.5cc diff in the two pistons.. The valve releifs are almost twice as deep on these pistons..... That's what it took to get the needed clearance.

With a 246@.050" cam, on a 108 LSA, I feel it will not have enough v2p clearance if it has flat top pistons. If it has dish pistons, maybe, but then its even that much more of a mis match cause you have less compression.

Also like others said... .515" lift does not work with stock heads. You will have retainer to guide clearance probs, coil bind, retainer to seal clearance probs, stock springs can't handle it it, etc.

Valve springs must be changed to handle the lift.. For this I like howards 98212, that takes care of springs but you still have the clearance probs.

You have to measure the space you have between the top of guide to bottom of retainer.. Take that spec, subtract your cam lift from it plus a .090" safety factor..

So you need .605" min between top of guide to bottom of retainer.

To get that clearance you can try added installed height locks, that moves the retainer/spring up by .050" (but keep in mind as the installed height widens the spring tension is lowered and therefor may not control valve and diff springs may be needed)

Have guides machined down... Or have spring pockets cut deeper, or install longer valves

Then you have to look at seal to retainer clearance, unless you are just running the little O ring valve stem seals.

If you are using a PC or umbrella type seal you don't want to crush it

Amillionoh7

iTrader: (1)

the cam is 480 lift. its a old lunati cam they dont make anymore. it does not hit anything free spinning. I did have the valve guides cut down a little when i was planning to put in my crane 500 lift cam. so as long as p2v is ok should be fine

jwfirebird

iTrader: (2)

alot of guys use a 14x3, with the perf rpm and holley dp. if it has the real deep drop it will clear the stock hood

jwfirebird

iTrader: (2)

kinda funny about the prius. i have a 305 in my scrap pile because i couldnt sell it and when it was in my car i had a neon 5spd, it was 4 tenths faster in the eighth than the firebird. i had done some mods to the 305 too and the neon was my stock DD

midias

Did you ever find the cam card?

Night rider327

iTrader: (13)

No, it is NOT .480" lift

If it is a Lunati bracket master 300, it is .515"
I have old paper catalogs from the last 20 years. I am not new to this. I used the bracketmaster cams in alot of customer's drag cars years ago.

Like I posted if it's a Lunati bracketmaster 300, (300 adv, 246@.050") then it's part # 10120412.... And that's .515" lift...

No if's, and's or but's to it.

Just cause you rolled the engine over by hand and nothing hits don't mean crap.. You spin the engine at what 5 RPM, maybe 10 rpm if you really try..

Not the 2000, 4000, 6000 rpm it's gonna run at.. Or the heat that causes metal to expand so saftey factrs needs to be added in..

Like p2v, you need a min of .080"/.100" min clearance.

You need .090" safety factor past your cam's lift with retainer to guide

Amillionoh7

iTrader: (1)

I am quite unsure why everyone is still on my **** about this. This is an experiment! with failure being an 90% option. I don't care and maybe if all goes terribly wrong this thread will make sure no one else ever does it. The 305 is probably the worst v8 gm ever made, so no loss. The only part I have a lot of money invested in is the carb so as long as it survives I will be happy.

midias

Sweet, take a video.

Some people you can tell them don't stick your hand in fire it is hot. Others just have to do it for them selves.

Amillionoh7

iTrader: (1)

will have the camera ready.

jwfirebird

iTrader: (2)

people get too wound up in the ideal combination, i seriously doubt the things going to grenade. at most it might not have any more power than the stock 305 and you may have to tweak the carb and dist to get some driveability. i always think about what this old guy told me "the thing will run with a gas soaked rag on the intake, if you dont believe me try it"

Night rider327

iTrader: (13)

It's not even about the "ideal combination" at this point.

It's about physical clearance between parts. When cam duration gets above 240* there is a high chance the valves will hit the pistons.

Stock valve springs are only 60-85# (depending on heads) and will coil bind with more than .450" or .460" lift.

The room between the valve guide and retainer only gives you enough room for about .480" lift at most

It can't run if the retainer hits guide.. It breaks rocker arms, rocker studs, bends pushrods when this happens.

It can't run if the valve springs coil binds and breaks

It can't run if valves hits the pistons.


Then you get into the part combo mismatch after all the clearance probs are took car of. Yes if all the clearances are fixed it will run.. It won't run good but it will run if the clearances are there.

It will not idle low, it will not have any power under 3500 rpm, it will run out of breathe and not have much power above 5500 rpm, it will need massive amounts of timing at idle., etc etc.. But it will run

Amillionoh7

iTrader: (1)

https://www.youtube.com/watch?v=o1CP...ature=youtu.be

https://www.youtube.com/watch?v=n4xB...ature=youtu.be

makaveli09

Well its alive! That's a good step. How does it run ? Any seat time ??

Amillionoh7

iTrader: (1)

Got base timing set. and carb set. did 30 min break in. need some more stuff before i can drive it. I will post a proper video next week

Amillionoh7

iTrader: (1)

https://www.youtube.com/watch?v=6OHv...ature=youtu.be

idle is nice

no seat time until throttle bracket gets here

jwfirebird

iTrader: (2)

sounds mean as hell, too bad it wont be able to back it up. lol

i just made one from my old bracket, there are a couple holes you can make sort of an adapter bracket, or if you are patient unlike me you can just wait.

Amillionoh7

iTrader: (1)

I am not racing the thing yet so sounding mean works for me. I cant wait to drive it

Amillionoh7

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Ok I have driven the car for the past 2 days. and ... I am very happy with the results. It has more power through the entire rpm range. My trip to work is 15 miles on the highway and 5 miles city and I am happy with the drivability in both situations. If anyone has any questions et me know

midias

Make a video of it running and driving I want to see how it performs.

Amillionoh7

iTrader: (1)

sounds like a plan for tomorrow.

Amillionoh7

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My butt dyno says it about the same as a stock lt1

Amillionoh7

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Video

Amillionoh7

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https://www.youtube.com/watch?v=bu-x...ature=youtu.be

Biggd4355

Do you have a high rpm crank in that?

jwfirebird

iTrader: (2)

she sounds good, if i heard that i would think it had at least a 350 with a cam

Amillionoh7

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Thanks. I am happy with it. It is not fast at all compared to my 4th gen. but is a fun cruiser

jwfirebird

iTrader: (2)

you knew that before you started im sure.