18 Degree 434 Chev - That Doesn't Make Power - Help

Old 04-12-2008, 12:05 AM
  #1  
torana434
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Default 18 Degree 434 Chev - That Doesn't Make Power - Help

Hi, I really need some help guys, I put my 434 ci small block chev together about 6 months ago, and had it at the engine dyno, the thing made just over 600 hp, to say I was @#^$%# pissed would be an understatement, I just couldn’t believe the numbers.

I put the engine into the car and ran it anyway, the motor ran fine but my quickest times were 6.41 @ 108 on the 1/8 and 10.03 @ 134 on the 1/4, with a mid 1.4 60ft, car weighs 3140 lb with driver.

I am pulling the motor out of the car in the next couple of weeks to try and sort out why it is not making the power it should here is everything I know about my engine??

1000cfm Pro Systems 4150 custom built by Patrick,
Dart 18* Intake manifold port matched,
Dart 18* Heads, 2.15 intake 1.6 exhaust, 68cc chambers I think??, 270cc intake runner, flow 352 @ .700 intake and 253 @ .700 exhaust
T @ D Shaft Rockers 1.6 intake and 1.55 Exhaust
Dart Little M block 4.155 bore, 9.010 deck height
JE Forged pistons part # 213107
Eagle 6" H Beam Rods ARP L19 Bolts
Eagle 4" 4340 crankshaft
Howard's roller camshaft part # 111233-10 Duration @ .050 278 intake 286 exhaust, lift at cam .450 intake .426 exhaust
Exhaust manifold 4 into 1, 1 7/8 primary 3 1/2 collector
MSD pro billet dizzy, 6al ignition

Could some of you guys please give me some advice on what and where to look to fix it, to make the power it should, thanks Dean
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Old 04-12-2008, 06:31 AM
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sc3314
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The cam is to small, you sure of those specs. The duration looks to be OK I would ad another .300 to lift. That should wake that engine up.
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Old 04-12-2008, 06:47 AM
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Racefab57
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The lift looks small to me too! David.
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Old 04-12-2008, 07:18 AM
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bbchevy
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I got 720 Intake and 660 Exhaust.
I think that should Be Fine other than maybe go 1.65 on the Exhaust,and then you will be @ 702 on the EX.
Later
G 8)
I was thinking maybe Gear or Converter Probs?
I had a 355 in a 3100 lb S-10 that went 6.50 in the 1/8 with 1.41 60' Times
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Old 04-12-2008, 07:37 AM
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jmarksdragster
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An engine with those part should make 700+. I would look closely at cam and cam timing, valve springs. Howard's do have some good components, just not sure if cams are one of them for an engine like yours. Size isn't the issue, just the quality of the grind possibly. Also what size pushrods? 3/8 minimum, 7/16 preferred. Something is definitely amiss....
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Old 04-12-2008, 08:01 AM
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itsabird
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i agree with the statement, that combo should be stronger, the lack of lift on the cam, is the thing that jump,s out at me, bigger stick, and good hook, should be a solid 9 sec car.
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Old 04-12-2008, 09:57 AM
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OneBadGMC
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Default Re: motor

Originally Posted by drz1972ss
The cam is to small, you sure of those specs. The duration looks to be OK I would ad another .300 to lift. That should wake that engine up.
That's lobe lift, not valve lift. Add in the rocker multiplier.
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Old 04-12-2008, 10:05 AM
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OneBadGMC
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Personally, I don't think it has enough compression for the camshaft thats in it.

I used the following numbers (head gaskets and deck height were an assumption).

68CC Chamber
-2.5 Dome Volume
.050 Gasket thickness
4.2 Gasket Bore
4.155 Cyl Bore
.010 in the hole
4" stroke

That all comes out to 12.241:1 compression.

Thats a BIG bumpstick for that compression. Of course, that can be adjusted with cam timing, but you didn't say where the intake lobe was closing.
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Old 04-12-2008, 10:12 AM
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maxpower671
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i'm thinking gear or convertor too.

what gears? tire size? convertor? RPM?

what is cam installed at?
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Old 04-12-2008, 11:38 AM
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jmarksdragster
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While I agree compression would help and the cam specs are not optimum there is some missing power with what he has. Degree the cam, check lift, springs, PR etc.
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