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Revs?

2K views 11 replies 6 participants last post by  curtis73 
#1 ·
I have a chevy 355 i will be installing into my camaro once finished, it has a holley 650 on a Weiand x-celerator(open plenum), a crane cam with 214 @.050 .454 lift, a 9.3:1 cr, crane roller tip rockers. The bottem end is stock with the exception of the sealed power flat tops(.030). Oh yea i will be running ported and polished 441 heads which are basically a thick casting 882.

Question is how high of RPMs should i be able to run it? would 6000 be a safe redline? Should i buy a larger cam(272 grind). Is that open plenum intake going to be a major torque killer? If so would it be worth the money to replace it?
 
#3 ·
If the valvesprings are up to it, 6000 is about where you'll quit making good power. Its also fine to swing a (well-assembled) stock small block up to 6000. I would definitely do a high-rise dual plane. Edelbrocks latest stuff like the air gap line has all but eliminated the weaknesses of both; it has the torque of a smaller dual plane with the hp of a single plane. You might be off by a couple digits here and there, but they are just about as good as it gets for performance street and would be matched perfectly to that 214 cam and 441 heads.

Edit: You could step up in cam since the 9.3:1 and light-ish car will support it, but even if you go up one or two steps in cam duration, we're still in dual-plane air-gap territory. Its not a requirement, but the $125 you spend on Ebay for a used one will make a nice change in SOTP (seat of the pants) performance.
 
#5 ·
I'm using crane valve springs with a 114lbs inst. ht and 340lbs. open pressure. Would it hurt my acceleration if i went with a larger cam and keep my 3.23 gears? The ignition is an HEI with a hyper tech coil, cap and rotor kit, what rpms is that good for. Dumb question, but how do you set up an hei to stop the revs at 6000, or do you just watch the tach and make sure they don't your self?
 
#6 ·
Just remember.
As fun as it is to rev (or say you can) your engine to umphteen thousadnds of rpm's, you really only need to run it to the level you built it for.
My blown sbc will run outta cam at 5800 and with my blower will probably peak hoses n tourque at mid 5000 or so.
I dont want to run it to 7 grand just because my parts will hold up to it. Run it were it stops making power and save yer engine. Hg
 
#7 ·
With that cam and heads you can expect the motor to stop making power around 5000rpm+/-. Yes the open plenum is too big for your engine setup.Unless its in a very light car and or with realy nasty gears in which case the cam will be too small and heads pushing it.
But with 3.23s and a mid sized car(which I'm guessing you have)I'd say your cam and heads and compression are spot on loss the intake for a Performer or RPM intake and you'll be set.
BTW 1 5/8 primarie headers are a must.
 
#8 ·
Yeah i've already selected the headers which happen to have 1 5/8 primaries, and i'm going duals with an h-pipe. So again should i limit the revs to 5700-5800, maybe less? It's gotta be a good street/strip performer with more emphasis on street performance but she'll be visiting the strip about once a month in the summer. Also my friend has an S-10/v8 that i have to beat, his set up is fairly mild with stock exhaust manifolds,so i hope i'll get him. What do you think?
 
#9 ·
I strongly disagree that the cam will only be good to 4500. I have a 218 cam in a 467 ci that makes strong power all the way to 5000, so it will make power to a bit more in your 355 than 4500. Heck, my 191/196-cammed LT1 makes peak power at 4800.

I'm not an expert on valvespring pressures so I'll let someone else answer that one. I can field the HEI questions. A pretty inexpensive way to get a rev limiter is with an MSD box with soft-touch rev limiting. It will also help stretch your RPM range. A well-setup HEI will provide plenty of voltage to about 4900. The MSD box will make that strong to 6000. If you still want more (but its overkill at this point) there is an ignition module that MSD sells that replaces the stock one under the cap. They claim it extends that range to 9000 rpms.
 
#10 ·
Id say the cam will be good to 5500 or so. Id say youll peak yer power at that to.
As far as yer friend goes...Dont turn him onto this site and let us know yer gearing, convertor, rear end setup and maybe we can help ya beat him. Lotta races won n lost off the starting line. Hg
 
#11 ·
The camaro has 3.23 gears and a stock convertor into a th-350 tranny, Yep i know stock convertors are JUNK(if you'd like to give me one with a higher stall i'd be more than thankful!) but i'm a broke high school kid with a shoestring budget(a very thin shoestring might i add). So a new convertor and Limited slip will be coming sometime in the summer, but as of right now my main goal is to unvail it on the last day of school(hopefully sooner :D ) and let the rest of the honda owners know who the boss is. So if you have any suggestions feel free to interject. Will a cam with 216@.050 be to doggy with a stock convertor?
 
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