BBC 454 engine build-up Questions

I recently picked up a 1984 vintage 454 from a motorhome with only 28K miles on it. Pulled the heads and the bore look almost new but a little surface rust from sitting!! I still see crosshatch on the cylinder walls. I may yank the crank and piston and give it a quick ball honing and put new bearings and rings in....

Anyway...the heads on these are those wonderful tiny peanut port ones..They are now under the workbench!

I picked up a set of PROCOMP (I know..but the price was right!) Aluminum heads PC3021-396 Closed Chamber oval port heads to use.

I also got another screaming deal on a complete COMP CAMS Mutha Thumper ROLLLER cam kit cam #11-601-8

I also plan on running a tunnel ram on this motor as well.

This will be in a 2800lb sedan.

Comp cams says the cam works best with 9:1 compression...I'm pretty sure this motor was 7.8 or 8.1:1 from the factory. By using the closed chamber heads I'm sure compression will go up a tad...Think this combo will work decent?? Just in a Saturday night cruiser. Thanks!


-Tom

 

Only for saturdays.......

 

let 's see you got a good solid low mileage motor so you can tear it down and over cam and over carb it and replace good bearings and rings just for fun? conventional wisdom on peanut ports is they will support up to 500 hp--- could have been a good deal ---might work on sat nite but compression that low won't sound good

 

Go buy some new head gaskets, put those heads back on. Now after you get tired of melting the tires off that thing, return all those parts!

 

If you plan on using the parts and have the engine down anyway. Get some Sealed Power hyper pistons with a cc dome on them that will get you 9.8-10 to 1 compression and do it right.

 

With it being apart...I now believe that will be the route I go!

 

new pistons --oh yeah and bore it ---your bargain is slipping away---isn't hyper just another way to spell cast

 

The only "peanut" head I remember was on 366 and 427 truck blocks, and WERE very restrictive for air flow. If you have the oval port, possibly the 049 casting, those are awsome for the street. The big brother rectangular port head is for high rpm and racing applications. What is the head casting number that you threw under the bench?

 

It might not make as much power with the lower compression ratio as you would like but by all means run it.

Don't let the naysayers get you down. The heads will be just fine, the roller cam will kill a little on the bottom end but so what unless you're using it in a 4x4. The tunnel ram will work fine. Forget new pistons, put the new heads on with good valve springs and your good to go.

The magazine readers will say tunnel ram won't work but believe me it will work. It will not be an economy king, it will be cold blooded when starting, but once it warms up it will be fine.

Don't expect 800 HP but ask yourself, why not? You can always put the cast iron stuff and the Q-jet back on.

Read this for info on how peanut ports could work also

http://www.carcraft.com/techarticles/ccrp_1010_cheap_big_block_chevy_engine_build/photo_08.html


And this for tunnel ram

http://www.carcraft.com/techarticles/0304_intake_manifolds_contrast/

 

Put a L88 cam in it

 

Get your pilot's license.

 

I'm getting ready to do a very similar build, with an '83 truck 454 engine. I'm not a fan of Pro Comp heads, and was going to swap a pair of early oval port cast iron heads on it, but ran across a super deal on oval port, 110cc chamber Edelbrock Performer heads with Crower roller rockers, so I'll use them.
I think the Comp Thumpr cam you chose is too much, unless you change the pistons to higher CR. Even then I'm not sure I'd want that cam with the duration it has. I'd prefer something shorter duration on both intake and exhaust. I think if you're stuck on the Thumpr, the 11-600-8 is a better choice. I'll probably go flat tappet on mine, and do something around 288/288, with .530" lift, and 110 LSA. The closer 107 LSA will make your Thumpr's lopey idle, but wont do much to make good lowend power for a mostly street application.

 

I think you will have a fun motor. But ain't gona have no bottom with that cam and intake. A fender banger for sure....

 

You will need probably a -21cc dome to get compression up to 10-1 assuming you are not going to deck the block.The 300cc ovals on those heads will get you decent low end power but not with that cam.1971BBC427 is about spot on with cam specs it will pull like hell from idle and you will be a lot happier.