Welp fellas,

Im getting closer got my heads ordered ( AFR 325 cnc chambers ). Have a brand spanking new block from GM 4 bolt tall deck 427. Now i have my rotating assembly Eagle# 11512 .100 over with L19 rod bolts. So now the question becomes what do i need to do to this all new block.

It looks like it has new cam bearings already and of coarse everything looks brand new like it should, but do i still have to get it tanked and use engine brushes ect? Also i need to get the cylinders bored for the pistons, since i am unfamiliar with big inch low compression engines do you suggest anything special here? rough hone with 240 ( i think been a while ) finish with 400 then glaze braker ball type? this is what i did last time. I really dont trust the machinist around here to do a good job :(.

I should be able to just drop it off and tell em give me .0045 skirt to sidewall clearance and not have to worry that they use the correct process for the newer moly rings, but i cannot. Any other work a new block might need that i may have overlooked? I planned to file fit the tops rings to .018-.020 and the 2nd rings .014-.016. I will be running a 250 shot on this Engine, any comments on this? I was also looking at doing a half-fill on the block anyone done this before and ran it on the street? Wow now that i think about it i got a lot of stuff to get ready!!!!.

I dont want to drive 200 miles to a decent work shop.

Shawn

I wouldnt run any block fill on the street, I've heard too many horror stories about high oil temps. I wouldnt think you would need it in a low compression, low rpm set up.

thanks BoB,

Never thought about oil temps!!! i bet since the oil runs down the pan rail on production big blocks that when you fill the block your cutting of a source for the oil to exchange heat!! never thought of this.

I think that the first thing I'd do is find a better machine shop. You really need someone you can trust to do the job right - that's one of the biggest assets any engine builder can have. You might find someone that can put the block in an oven and run it thru a few cycles to make it a bit more dimensionally stable before machine work starts. Good luck!

Welp fellas,

Im getting closer got my heads ordered ( AFR 325 cnc chambers ). Have a brand spanking new block from GM 4 bolt tall deck 427. Now i have my rotating assembly Eagle# 11512 .100 over with L19 rod bolts. So now the question becomes what do i need to do to this all new block.

It looks like it has new cam bearings already and of coarse everything looks brand new like it should, but do i still have to get it tanked and use engine brushes ect? Also i need to get the cylinders bored for the pistons, since i am unfamiliar with big inch low compression engines do you suggest anything special here? rough hone with 240 ( i think been a while ) finish with 400 then glaze braker ball type? this is what i did last time. I really dont trust the machinist around here to do a good job :(.

I should be able to just drop it off and tell em give me .0045 skirt to sidewall clearance and not have to worry that they use the correct process for the newer moly rings, but i cannot. Any other work a new block might need that i may have overlooked? I planned to file fit the tops rings to .018-.020 and the 2nd rings .014-.016. I will be running a 250 shot on this Engine, any comments on this? I was also looking at doing a half-fill on the block anyone done this before and ran it on the street? Wow now that i think about it i got a lot of stuff to get ready!!!!.

I dont want to drive 200 miles to a decent work shop.

Shawn

Hi Shawn,
Couple of general suggestions,,,
I would at least pull all the oil galley plugs & have it cleaned real good preferably in a jet washer after the bore & hone.
I would recommend removing the cam bearings if you are having the block bored.
New ones are cheap & cleaning the passages is not real easy with a small hole at the top.
Then clean the bores again after you get it home with hot soap & water & spray with WD40 & dry it real good.
If you are not comfortable with the local shop take a drive,,, if the bore is not right you are not going to fix it in the driveway,,,
Find a shop that uses a torque plate.
The clearance will be built into your pistons. In other words, if it is a 4.350 piston it will actually be about 4.3450 if forged.

You will probably want a bit more top ring gap for a 250 shot, follow the piston manufacturers guide here.
Use .020-.022 or .005- .0055 per " second.

BTW,,, nice heads,, :waving:

You will need to check the deck height as well if you want to get the quench where it should be. I would say there is a pretty good chance you will have around .020" deck height, when used with a .038"-.041" head gasket will give you less than desirable quench. I would think that would be pretty important when running nitrous. My 2 cents.

Thanks,
I have decided to swallow my pride and take it to the only decent performance machine shop in the state. I hated dealing with this jacka$$ last time, but hes really the only choice.

Would anyone have a problem running a new GM block a bunch of the locals insist it will be weaker than a heat tempered used unit?

Probably won't be noticeably weaker but won't be as dimensionally stable, from what I understand about heat cycling an engine. Pi$$ the locals off - go the other way and have it cryo treated - that's supposed to make a noticeable difference in stability and wear.

ROFL dude this is ARKANSAS, ill be lucky if it gets bored with Torque plates someone made theirself of an old John Deere tractor head. Maybe i could grab some Liq nitrogen myself and try it :)

These guys look at me crazy when i ask for something out of the ordinary which around here is about 25 years behind the mainstream.


:)