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Discussion Starter #1
Okay...
My 400 Small block is built as follows:
block is .040 down
10.5:1 Hypereutectic pistons
Factory correct rods
Factory crank machined .010 down
General Kinetics solid cam:
* .454 on 268 degrees and .050 is 218
* cam time is:
* intake open -1 btdc
* close 39 abdc
* exhaustopen 39 bbdc
* close -1 atdc
Factory correct(new)lifters, push rods, and rockers
New valve return springs matched to cam
New valves(1.94 and ?1.68?)
New guides, seals, and seats with 3 angle job
Performer RPM aluminum manifold
Holley carb(can't find #)
Full Accel ignition-HEI to Plugs
Hooker headers
Flex fan
Now...
The questions I have are:
Is this intake the best option I have for this motor considering: my cam choice and that it REQUIRES a 1" spacer to clear the carb from blocking the brake booster input point?
Should I replace my mechanical fuel pump with an electric?
What should I be hitting for fuel psi?
Is a holley rebuild a likely cure to small fuel puddles on both sides of the carb on the intake?
Should I replace the carb to manifold gaskets before attacking the carb?
Will the addition of 1.6 rockers chase the piston to closely?
Will said rockers increase hp noticably?
What size carb would be best here for mostly daily driver action?
Do I really want NOS or is that my right foot talking? I'm thinking of a good way to use up that 1" spacer area...
Where are the model #'s on Holleys?
How much horsepower should be coming out of this mill on 91 octane?
Should I consider an octane booster?
Who the heck is General Kinetics(cam)?

That's all I can think of right now. If any of you motorheads out there see something in that build that doesn't seem right, lemme know. Sorry this got so long...

Thanks for the help, y'all!

Rob
1BADS72

[This message has been edited by 1BADS72 (edited 12-06-98).]

[This message has been edited by 1BADS72 (edited 12-06-98).]
 

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Rob, what rear gear ratio and tranny are you running? The spacer on the RPM manifold will move the power curve up even higher. Your cam is mild, and with 10.5 compression, you may have to deal with detonation cures. I would recommend a cam like the Comp Cams Extreme Energy XE268 to match the manifold power range better(224,[email protected]).Did you do any bowl blending on the heads? Getting all the parts to work together is important.
 

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Rebuild Holley and check float level to correct gas spillage. Full roller rockers highly recommended, 1.6 ratio would help too with this set up for sure. 400 with stock rods is mainly a torque engine, a dual plane intake may be better here. Should fly I'd think. tom
 

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Discussion Starter #4
Sadly she still has the 2.73 one legger behind a 350TH. I got the car with about 5k on both the motor and tranny. The tranny was done by a shop shortly after the motor. Its apparent in the paperwork I got with the car that a kid put together the motor, shelled the trans and his folks got it rebuilt by a shop to match the motor. I got about 400 miles on the car before I lost the better portion of the #1 piston. I don't think the kid had a clue...
I chose the RV style cam for the low end torque. Because: I plan on pulling a race boat next summer with it, most stock harmonics can't take hard runs past 4500 and the rear is so freaking short that I'd theoretically never have to leave first gear with a race cam. Now, after toasting whatever is on the right rear, I've decided to go to a taller gear and a posi unit. I looked into lockers and even found a guy locally that has one in his truck. Don't like them at all. Too loose for mostly street action.
I did not match the heads to the manifold as the manifold is the component I want to replace. I would keep it and just get rid of the spacer to get my power range down, but that isn't feasible with the brake booster line in the spot its in. curses...Nothings ever easy...
As she sits right now, she moves pretty good. She can easily go fast, however I have no need to go fast. I have a burning desire to go quick, yet keep her a daily driver.
tom-thanks, didn't even think of the floats.
Rob
 

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Rob, the Performer manifold is about 3/4" shorter than the Performer RPM and matches the rest of your engine better. It will give you killer low-end and mid-range. Maybe this will solve the clearance problem?
 

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I built a 400 that has the same cam but lower compression. After 20,000 miles it lost a head gasket. I pulled both heads and had larger valves installed. It was a huge improvement in power and torque. If you find a reason to pull the heads I highly recommend upgrading the valves. It will noticeably improve your pulling power and is well worth the money.
 

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Discussion Starter #7
corvgreg-will head to local speed shop this weekend to compare, thanks for the lead.

Bill70-what valves did you go to?I assume 2.02 and 1.98 but there are others. Where did your 400 come from? I think I've traced mine back to a 1972 C-20 or C-30. Haven't run the numbers yet.

Can I go with heads off a different small block? I pondered 2.02's but couldn't afford the added milling cost considering everthing else in the heads are new.

Anybody outthere got a copy of DESKTOP DYNO?
I'd like to feel out reactions to it and see if I want a copy myself.

Thanks for all the help so far!
Rob
1BADS72
 

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Rob, I would have a good bowl blend done to the heads instead of replacing valves or the heads themselves. The 2.02 intake valves probably won't help until you're above 4000- 5000 rpm. You should have 1.6 exhausts already. Bowl blending could be done yourself, or you may pay $150 to $200.I have the desktop dyno, and it may be of help to compare the same type of cam grinds. I have talked to Comp Cams about hydraulics and solids, and they stated that the software is favoring solids by too much, and it can't recognize differences in opening and closing ramps. They said their Extreme Energy line has ramps similar to a solid lifter cam. Also, the Dyno program is real general on intakes, heads, etc. and power ratings are too high(on my engine I am guessing it's 40 to 50 horsepower less than what Dyno says)I would still call the cam manufacturers for recommendations.
 

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Discussion Starter #9
um, duh...
What's the diff between a solid cam and a hydraulic cam? I assume it is respective to the type of lifters each is intended to be combined with. Am I correct?
 

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Rob, my 400 was a 2 bolt block out of a 76 4 wheel drive pickup truck. The valves I upgraded to were Manley stainless 2 .02 int, 1.60 exh. They made a noticeable improvement all across the power band, not just 4,000-up. Hopefully you are not using the original heads because they contain 1.72 intake valves and cannot be sized up to the 2.02. Good luck.
 

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Discussion Starter #11
Bill-
I measured them when I tore down the motor. Intake is just under 2" on a stick. Didn't have a mic available to verify, but I think they are 1.98".
I also found that the mains are 4 bolt. I would like to find a place to run the numbers off the block to find out for sure where it came from.

Rob
1BADS72
 
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