Engine block machining/build question

tkeaton

tkeaton

Master Velocipede Alchemist
Joined
Mar 20, 2005
Location
Chattanooga
I've spoken with a few machine shops in my area about a project I am about to start and wanted to share the response I've received from one of them to see if I can get some additional opinions.

454, 4-bolt
Wanting to go to 467 (468 depending on what you want to call it)
Powerplant is going in a street truck/hotrod, will not be raced, will not be a "performance" engine. I want to do 467 because that's what I want to do, but don't have any power requirements or anything like that. This will be a weekend cruisemobile. Building it to take advantage of 1800-3000rpm range. Or something like that...

Shop A comes highly recommended, I've stopped and talked to them, pricing is great, turnaround is great, etc. Told them what I wanted, they said "Ok!"

Shop B also comes highly recommended, more of a race engine shop however. Stopped to chat, told them what I wanted, pricing is great, turnaround is a little slower (not a big deal.) The difference is that they strongly recommended only going .30 over to start. When asked about this, the response was something along the lines of build to .30 over the first time and then when I want to step it up, or when engine needs rebuilding/re-machining, then go .60 over. Something else along the lines of if .30 over goofs up, you still have room to go bigger. If it messes up at .60over, then block is toast, so start smaller then step up later or if problems develop.

Other than $ involved to machine twice, buy two sets of pistons/parts/etc, how much does the rest of their reasoning hold up?

Shouldn't I be comfortable with the machining the first time, from either shop, that the block won't be f'd if I go .60 the first time?

What am I overlooking? I have only rebuilt non-damaged, non-overbored SBCs, I am not an engine builder, I don't really know much about what I'm being told.
 
I would only bore the necessary amount to clean up the cylinders and get them back within spec.

Let the amount of wear dictate the amount needed to bore.

Could be as little as .010 over stock bore if not worn.

Could also need .050-.060" to clean it up all depends on the cylinders.

I would just bore & hone as small as necessary.

Wait until after the block is cleaned up and crank turned to see what pistons, rings , and bearings to order.

No need to spec it to .060" over if it's not needed, only wastes machine time and $$ if not necessary.
 
X2. Let the shop tell you how much is required to clean up the block no need to go too big. That can actually cause overheating issues too. I promise you won't tell a difference with the butt dyno from a 454, a 468, or anything in between. On an actual dyno there won't be more than just a few HP in that small of a displacement change.
 
I don't think they mean if something in the machine work goofs up at .060 either. If you only go .030 and 6000 miles later a piston ring breaks or a wrist pin clip comes loose and you scratch up a cylinder it can be bored to .060 pop in some new pistons and be riding. If you bore it out max now then you'll have to hunt down a block or sleeve it.
 
I agree with all the above posts. The 454 blocks are known for their strength and ability to make power. The most important thing on a 454 is the head. Spend your time/money on them
 
Well let me be the odd one!! Lol 60 over is really not "to much" the max bore on a 454 is 120 over, now that's MAX! my friend as one bored 100 over runs 7's in the 1/8 now if thats not your goal and you are only going to "cruse" dont bother wasting the money on boar. You can build the top end and get alot out of it! But if you just HAVE to go 60 over then piss on it! Go for it! There is room to go bigger if need be!
 
He beat me to it! You can bore the hell out of a 454 block. .120 is almost 1/8th of an inch!

I'd spend my money on a cam, springs, pushrods, and a little bit of head work. Maybe bump the compression up some.
 
Check out this build. Dyno
Numbers and real costs.

http://www.hotrod.com/how-to/engine/ccrp-1010-cheap-big-block-chevy-engine-build/

Made stupid power with dyno proven numbers to dollars.

The bore will make very little power difference.

For what it sounds like you want to do, spend your money on professional carb tuning or an efi setup and some dyno time.

This will get your drive ability perfected and IMO be more useful and worthwhile.
 
I'm loving that torque figure.... :huggy:
 
You can't beat a big block for torque on the cheap, LOL.

Seriously though you won't notice the extra cubic inches on a street motor. If you're going for all out racing where every HP counts then you can worry about it, for a street strip cruiser just let the machine shop clean it up and go ride!
 
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