I am currently building up a 406 for my 92 RS. This is my first engine buildup, and I want to make sure I am doing the right thing with the stuff I am buying.

Stuff I have:
1. 400 Block - 2 Bolt
2. Scat Cast Profiled Crank (PN 94003755P)
3. Miloden Splayed 4 Bolt Main caps
4. Eagle 3D H-Beam Rods (ARP Bolts)
5. KB Hyperutectic Pistons (KB-139) (.030 over)
( http://www.kb-silvolite.com/page35.htm )

The info on the pistons say if I run a 76cc head, I will get 10.1:1 compression, and with a 64cc head, 11.4:1 compression. Is 11.4:1 too high for 93 octane pump gas?

I am not sure which heads to go with. I was thinking AFR 195's. What advantages would I see if I went with the 220's? I will be using Comp Cam Pro Magnum 1.6:1 full roller Rocker arms.

I want to run a SuperRam EFI setup. What would be a good cam to use? I want a Hydraulic Roller (for reliability, this is a daily driver). I dont want the cam to be fairly agressive, fair idle is OK.

I have heard it is a good idea to ceramic coat the top of the pistons? How much would that raise compression?

Thanks guys. This is only my first round. As I aquire more parts, I will be asking for more help.

 

Yes, unless you have about 240 degrees cam duration at 050 and about a 110 lsa.

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I am not sure which heads to go with. I was thinking AFR 195's. What advantages would I see if I went with the 220's? I will be using Comp Cam Pro Magnum 1.6:1 full roller Rocker arms.

If your going to keep the rearend gear at 373 or less, I would stick with the 195s. Or go with the TFS23s and the money you save get them flowed.

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I want to run a SuperRam EFI setup. What would be a good cam to use? I want a Hydraulic Roller (for reliability, this is a daily driver). I dont want the cam to be fairly agressive, fair idle is OK.

Your really going to need something in the 220-230 range at 050 (depends on gear ratio) Get as much lift as you can find. 550+


It won't raise compression, just make more heat with the compression you got. Some say it reduces octane requirements, I don't know personally. You really can't apply it yourself. Try http://www.swaintech.com/price.html
and be prepared to reach deep into your pocket.

 

Just out of curiosity, what does the rear gearing have to do with the size heads used? I do plan on 3.73's.

 

There is an indirect correlation. As you increase port volume, the flow velocity naturally slows down. The steeper gear will automatically put the motor at a higher rpm and increase torque multiplication reducing any problems that might be experienced with loss of lowend due to bigger ports.

The inverse is also true, as you go with a steeper gear, you need to make sure there is enough port volume to feed the motor at the rpm it will be required to turn with the lower rearend gear.

It's really just an extension of the thought of matching cam/intake and heads,,, to the next level, the drivetrain and entire combination.

Your going to really need to work on suspension and traction. The Superram on a 400 will make 500+ ft/lbs of torque at about 3500-3800. When you combine that with the 373s, first gear will be hell on the tires.
I would look for ways to minimize torque a low rpm... slightly more cam duration maybe (not much else you can do). If you put 220+cc heads it will come on like gang-busters and still kill the tires.

[This message has been edited by jcb999 (edited June 07, 2001).]

 

I have BMR Adj. LCA's, LCA relocation brackets, and panhard rod. I am putting on Spohn SFC's soon, along with a set of IROC swaybars with poly bushings. Will I need more?