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View Full Version : Rebuilding a (B)ull (S)hit Block- Is it worth it???



Dizzo7693
06-29-2003, 06:06 AM
Okay guys, here's the deal. I have a BS block that has been taken apart for rebuilding. Block is gutted. My Question is that are the BS blocks good for rebuilding? I know we are blessed to have forged cranks in our motors, so which means that it is spray ready as well as a full build up on the bottom end.

Are these blocks worth the rebuild?
Can you put LXi Internals in it? (Rods, pistons, bearings... etc.)

I just wanted to check and see what you guys have to say about this one.
Also what are th basics for building a head up. Besides port and polishing. ( ex. Valve springs, retainers, valves, cam... etc.)

P.S I have the LXi (A20A3) in my car right now, but I think I hear it knocking around 2.3k rpms. I just want to be able to have a backup motor, as well as a bad ass motor, just incase the LXi Blows.

Lots of Questions Bear with me! Thanxs:smokin:

bobafett
06-29-2003, 06:32 AM
ok i will give this a SHOT, but i am not positive about all of it. :)

yes they are worth the rebuild. obviously since you are thinking of forced induction (n20) the cast iron block and forged crank come in handy. with a b series motor (the obvious swap canidate) youre switching over to aluminum block i think, which isnt IDEAL for FI

i also think you can put a20a3 internals into it, because i think the blocks are the same, it was my assumption that only the pistons and maybe the head were different, but anyway i think its the same block.

and i dunno about other ways to build up a head, other than what you mentioned. :)

as for the knocking, buy 92 or 93 octane gas AND/OR retard your timing a couple degrees. :D

AccordEpicenter
06-29-2003, 09:19 AM
If you are going to do a rebuild, first you have to have the block magnafluxed and you have to see if its still within spec for all the measurements, particularly for the cylinders, if it isnt youre wasting your time with the block, its bad. All a20 parts are interchangeable. If I were you id have it bored .030 over, it will give you a much better ring seal than if you used the already worn standard bores.

Dizzo7693
06-29-2003, 04:37 PM
Another Question is that : Is it possible to bore out the head enough to put b series pistons in there? Or what will be the right piston to use for this setup that I would like to do.

A20A1
06-29-2003, 04:49 PM
BS is like the A20A1 and A20A2 engine codes

BT is like the A20A3 and A20A4

Dizzo7693
06-29-2003, 05:23 PM
Thanks for the help once again. But I would like to know what will be a good and safe setup for nitrous? Ex. Pistons? Connecting rods? Bearings?

Also, should I do anything to the crank if it is not scared?
Ex. Have the oil passage ways drilled out for more oil to the bearings?

A20A1
06-29-2003, 07:11 PM
Keeping the motor detonation free is a hgiher priority then worrying about more oil to the bearrings.

I use to rev my a20a1 to 7,500 rpm frequently. I just now took it apart and all the bearings looked healthy except for the crank to connecting rod bearring for Cylinder #3. I'm pretty sure that was the same cylinder where my plug had shattered and was missing the ceramic. I blamed that on detonation from lack of cooling to the block and head. Possibly from not using the right type of heat range for the plugs.. too much ignition advance and too fast a rpm for the water pump to handle.

At the time I ran 20w 50 and had a cam regrind suited for higher rpms. The valve guides/seals gave out in every cylinder and I had masses of oil on the stems, but I never saw signs of a valve hitting a piston. and I never saw blue smoke out the tail pipe??? which I found pretty odd.

BTW Any lack of oil to the #3 bearring was my fault since I know I wasn't keeping the holes particle free when I replaced the head gasket once... I'm pretty sure that clogged the oil passage.


also, on my A20A3 I've add a spacer to the pressure relief spring on the oil filter housing. It bumped up the pressure some. I haven't noted the Psi at 3,000 rpm yet, but when I do i can compare that with the stock specs out of the chiltons manual

Dizzo7693
06-30-2003, 08:14 AM
Alright, So your saying that when you had the crank grinded it fucked up your motor because of the fact that the oil passages got clogged??
Is that what you are saying?

And also A20A1, what all did you have done with the bottom end?? And what was the performance on that? Were you impressed?

Thanks again for the assistance.:smokin:

A20A1
06-30-2003, 12:46 PM
not exactly, the oil passage might have been clogged when I replaced the head gasket... but I have a good reason to believe detonation put the extra wear and tear on the # 3 crank/rod bearing.

The bottom end was stock.
I'm sure now that with a higher oil pressure and my detonation problems cured. I could take the motor up to 7,500 rpm all day.