454 Rebuild Advice

[Regal454]

Hey whats up g body forum for the most part ive been on the outside looking, but now its time I think I step in...

So heres my dilemma i finally have stacked enough cash to start my rebuild on my mark IV 454, but i don't really know where to start (better yet where to put my money first). Im doing a performance rebuild so ill most likely end up buying one of those nice kits from summit with all the gaskets and new forged pistons for like 600 bucks. I have a bit of experience assembling motors from back in my high school days, but this is the first rebuild ive ever done, but im not afraid of doing the break down and reassembly myself, but i know the block will probably have to see the machine shop. That being said the motor has been in my garage since i bought it last year and before that it had been sitting in another guys garage so its pretty dirty. I removed the heads a while back and besides me spraying it with wd40 every now and then and turning it over its just been sitting covered in plastic. So my question to you if it was your rebuild how where would you start? Any feedback will be appreciated THX

 

[larryo454]

Hi what kind of engine do you want? A street engine or a strip engine along with this is the bbc has a big problem with valves sticking in the iron valve guides.so a cheep alum head like a pro comp fully assmbled for a mild build up to .540 lift on the cam.

 

[Regal454]

Thx man, well i wanted to build i high performance street motor that will probably see the strip once or twice a year and hopefully run off in the 12s for starters. As far as my heads go i already spent my money on some iron 781 castings with some port work already done to them is their any other way around that problem? Also my question was more geared toward where to start with the short block. Thx again

 

[84e/c]

take it all apart to find out exactly what was up with things. make sure the block is good and rebuildable. then its all up to how thick your wallet is.

 

[larryo454]

take it all apart to find out exactly what was up with things. make sure the block is good and rebuildable. then its all up to how thick your wallet is.

X2 on all a part but the head is what tells you what type of piston to get.Stock crank is good and stock rods out of a 366 or 427 tall deck block are stronger then a car or truck rods but not really needed.The 781 are a good head just put the bronze guides in to help stop the chance of the valve sticking in the guide and dropping the head off and going for a sh*t.

 

[khan0165]

... like you, I'm not that experienced... Nor do I know anything about big blocks,

but judging from the sbc in my car, basic machine work is well worth the $$$... get the cylinders honed, block decked, and if you can afford it, get the crank and rotating assembly balanced.
if the motor has been sitting for years, a dip in the hot tank will clean out everything and you'll start with a fresh block.

not only will you see noticeable power gains, but the motor will run smoother and last alot longer.

... Welcome to the forum! Start a build thread, and keep us posted!

 

[stomis]

Its not hard to get 500hp out of 781 BBC heads.

.540 lift cam in a big block is nothing, at all. Thats like beyond mild daily driver conservative.

Bust it down and inspect first. If your going to get new pistons anyway this is your chance to pick up cheap cubes. Depending on casting big blocks can be bored a huge amount vs a small block. Its not uncommon to see them .080 or .100 over.

Send it out to be checked, tanked, bored and honed. Thats the bare minimum you can do. Shouldnt cost you more than $500. Start there.

 

[mickey-d]

I will have to agree with larryo on the bronze wall guides, good choice. Those are pretty good heads dead stock. I'd send them out for a "clean-up cut", and send the block out for an .030 bore, and a "clean-up" cut on the deck. Next, the crank. Have the machine shop chanpher(sp) the oil holes, polish the crank, and "zero balance" the crank so you can use any harmonic balancer and flywheel. Any good steel rods will work, they are all strong enough unless you get over 7000, 7200 RPMs. Don't go with Moly rings if you are going to street drive the car, stay with the cast iron rings. They seal quickly, and wear much better. Don't get too crazy with a camshaft, especially if you're going to run power brakes. Too high in the numbers, less vacuum to run your brakes and other accessories. Get a lot of opinions, take your time, and shop around for EVERYTHING.
mickey-d :lol:

 

[dogsht]

If you are getting pistons as you say and therefore at minimum reconditioned rods and then as Mickey-d says with the crank having it champhered polished and having the rotating assembly balanced well thats a lot of labor cost. You might find that now days you can find complete balanced rotating assemblies or drop in ready kits to match your heads & compression goals including a new stroker crank rods & pistons for not much more as you don't have the machine shop professional labor cost. Seriously price it out both ways and you might find the total end cost to be about the same. Only you will have new parts and depending on pistons/bore chosen around 496ci.

 

[larryo454]

I love the total seal ring but the price is up but you get what you pay for to.And for the most part that valve train is the weakest part of the bbc.