Big cam with low CR heads, what to expect? - Hot Rod Forum : Hotrodders Bulletin Board
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Old 06-30-2012, 08:41 PM
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Big cam with low CR heads, what to expect?

Hey guys, please tell me how this engine will be like:

30 over SBC 350
Stock dished pistons
Edelbrock Torker II manifold
Summit 234/234 @ .050, 292/292 adv. cam
Holley 600 cfm
custom headers
882 heads mildly ported

it's going in my dune buggy:

very light, dual seater, mid engine RWD
TH350
1.800 rpm stall
3.50 LSD toyota supra IRS
31 in tires

My main concern is the crappy 882 heads, for now I don't want to spend more money, I must live with them for awhile, I know the cam is way too big for the low CR this heads give, what can I expect from this mismatch? poor driveability?, very bad idle?, little low end torque? or all of the above?

Since the buggy is very light, just the esential parts to keep it togheter, I hope it won't matter much, I will change to better heads in the future, or sooner if I hit the lotto.

please tell me what you think.
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Old 06-30-2012, 09:04 PM
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not a fan of the intake, never used one but I've never heard anything good about the single plane torker manifolds. since the wieght of the vehicle is very light this will help you quite a bit with the lack of compression and duration of the cam. I would imagine that the engine will want a decent amount of advance on the timing but with all you have and setting the timming a bit more advanced i think you will be okay.
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Old 06-30-2012, 11:02 PM
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I agree with My87Z. You'll need tons of ignition lead with a custom curve. At idle you'll have a difficult time setting fuel mixture and it will likely smell very rich.

When you get around to it, sounds like you need some ported 305 heads. The chambers are small to get your compression up, but the ports need work to handle that cam.

The torker intake is a terrible choice for that combo and it will make things more frustrating from a tuning standpoint. Find someone who actually needs or wants a Torker and trade them for their Performer or RPM.
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Old 06-30-2012, 11:31 PM
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I've seen several pics of of a plenumm divider installed in the torker manifold, seems pretty easy to do and see if it works.

so, the main problem seems to be the manifold not the 882 heads, right?

a performer manifold + 882 heads will work fine with the 292 cam?

how about the very low compression ratio? I tought that was the main problem.
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Old 07-01-2012, 05:56 AM
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Use around 25 degrees of timing at idle and 38 total. Then add 10 more with an adjustable vacuum advance.

You need more stall converter. A 3000 rpm 10 inch stall should be about right.

Use an RPM intake (regular, not the air gap).

882 heads are not very good. A good set of 64cc heads would be really wake up the engine. I would expect at least a 50hp gain with a head swap.

Low compression isn't you biggest problem. I would put the low stall converter as the biggest issue, then the poor flowing heads, then the intake, then finally the compression ratio.
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Old 07-01-2012, 08:51 AM
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what would it be like driving the buggy at slow corners on a tight windy road with a 3.000 rpm converter?

Does it need to rev up to 3.000 to start moving? or just fully engages at that speed?

I guess the millage would be quite low, but if I wanted good millage I would of used a geo engine instead.
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Old 07-01-2012, 01:20 PM
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Find a set of 305 HO heads for this thing.

Get a 3000+stall converter and some gear or change the cam
218@.050 or less.

Yes a 3000stall will drive at low speed.
no the engine does not freewheel to 3000 before the car moves, reguardless of throttle input.

with a 3000+converter the engine will hug the 2000+2500 rpm range while accelerating from a stop with part throttle input (normal driving)

instead of the typical 1000-1500 range seen with a stock low stall converter.
The lighter the car the easier the car moves with little throttle input even with a race converter.

get a a dual plane manifold.

This is about as fubared a combo can be.
low cr low head flow, crap manifold too big cam. late intake valve closing point ='s lame performance.

Its a lot cheaper to change the cam for the right one and use a stock SBC dual plane manifold than buy a 3000+stall converter
For offroading use a Qjet carb and stock intake manifold. use a stock or small near stock cam that makes torque.

Last edited by F-BIRD'88; 07-01-2012 at 01:31 PM.
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Old 07-01-2012, 03:00 PM
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^^^ got me laughing

I agree
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