.060 Overbore

95TalonOwner · 07-10-2012, 06:42 AM

Anyone ever gone 60 over? My block is already 40 over and it needs to be cleaned up to 60 since there is no 50 option for our motors. Otherwise I'm also trying to source another block soon.

Thanks.

eclipse420ags · 07-10-2012, 07:24 AM

Those walls will be mighty thin. If you do it keep us posted idk if has ever been talked about with our cars.

95talongirl · 07-10-2012, 07:42 AM

Yeah, you are starting to push the service limit on that.... I'm sure it would be ok if the car was in stock trim, but not sure how it would hold up under more power. Seems like the thin walls may become a problem.

BogusSVO · 07-10-2012, 07:48 AM

Find a shop that can sonic check the block, this will tell you the thickmess of the cylinder walls. That should tell you if you are ok to go .060 over.

But the cost, about $100, you may just want to get another block.

95TalonOwner · 07-10-2012, 08:50 AM

Thanks everyone.

So does anyone close to Milwaukee have a block? lol

MJcanada · 07-10-2012, 08:59 AM

Do the,4g64s come with thicker walls? standard bore on those are .080 larger than the,63. Mine, friend just bored is,.020 which would be 87mm bore.

95TalonOwner · 07-10-2012, 09:05 AM

This is on a 420a. Stock bore on a 420a is 87.5mm.

Fotowntalon · 07-10-2012, 09:29 AM

Walls should be fine in terms of strength, I would be more worried about in terms of heat dissipation. If it was a track only car, I'd say go for it, but with a daily driver, and possible heating problems i dont know. Also You would need customer pistons, whether you go .050 or .060 over. Why not go .045 if you can get away with it?

95TalonOwner · 07-10-2012, 09:49 AM

The problem with those sizes is I cannot find rings to fit. I don't want my machinist to get into all of that if I just find another block to punch to .040 instead.

Fotowntalon · 07-10-2012, 11:05 AM

custom rings isnt that hard to find or get made. All depends on the money you want to spend.

bryanwheat · 07-10-2012, 11:16 AM

Quote:

Originally Posted by Fotowntalon

custom rings isnt that hard to find or get made. All depends on the money you want to spend.

It would be WAY easier and cheaper at this point for him to just find a good block and bore it .020.

BogusSVO · 07-10-2012, 11:24 AM

Or if he has good forged .040 pistons, get another block and take it .040 and reuse the pistons

95TalonOwner · 07-10-2012, 11:43 AM

One of the pistons in question....

BogusSVO · 07-10-2012, 11:46 AM

That ^^^^ is NOT a good resuable piston.

New block and .020 over for you.

MJcanada · 07-10-2012, 03:40 PM

Quote:

Originally Posted by 95TalonOwner

One of the pistons in question....

No sir there is no question here. Deff junk. What does your cylinder wall look like?? Lol

Id say new,block and pistons. as svo suggested

95TalonOwner · 07-10-2012, 03:55 PM

I'm not questioning the pistons because I'm not retarded. I'm either boring the block .020 more and calling it a day or finding a bare one and having it punched out .040 again for my 2.2L.

MJcanada · 07-10-2012, 04:15 PM

Quote:

Originally Posted by 95TalonOwner

I'm not questioning the pistons because I'm not retarded. I'm either boring the block .020 more and calling it a day or finding a bare one and having it punched out .040 again for my 2.2L.

I didn't think you was.,, was, just stating some carnage there lol. Ill ask my brother what he thinks he is turbo car guy majoring in chryslers. Though imo I'd say, you could get away with it. You could do .045 .050 depending on how much bring is needed. You can contact nippon racing or maybe cp and maybr wesico and have them, make a custom piston. I'm sure if they will make, the piston they can do the rings as,well.

95TalonOwner · 07-10-2012, 04:29 PM

I have a source for the parts no problem, just debating on size, that's all.

MJcanada · 07-10-2012, 05:47 PM

Quote:

Originally Posted by 95TalonOwner

I have a source for the parts no problem, just debating on size, that's all.

How bad is your cylinder wall scared up? that really is, what decides which size can be used. Anyone that makes custom pistons should be able to make/source rings to fit.

95TalonOwner · 07-10-2012, 06:07 PM

It needs .020 to clean up.

MJcanada · 07-10-2012, 06:44 PM

Quote:

Originally Posted by 95TalonOwner

It needs .020 to clean up.

I would say you would be fine with that but do the sonic check just to be sure.

BK85 · 07-10-2012, 09:22 PM

Where can you find pistons and rings larger than 40 over for the 420a? I haven't been able to find them anywhere.

BK85

95TalonOwner · 07-10-2012, 09:32 PM

Quote:

Originally Posted by BK85

Where can you find pistons and rings larger than 40 over for the 420a? I haven't been able to find them anywhere.

BK85

Custom pistons.

WES_393 · 07-10-2012, 09:49 PM

Quote:

Originally Posted by MJcanada

Do the,4g64s come with thicker walls? standard bore on those are .080 larger than the,63. Mine, friend just bored is,.020 which would be 87mm bore.

No, the 4g64 isn't made with any thicker walls. 4g64 stock bore size is 86.5mm which is only 1.5mm (.060 over) from 4g63 pistons (85mm stock). It's not recommended to bore the 4g64 much larger unless you have had the cylinder walls check very thoroughly. Plus, I only know of forged 4g64 pistons going to 87mm so any larger and you would likely need custom pistons.

MJcanada · 07-11-2012, 02:08 AM

Quote:

Originally Posted by 95TalonOwner

Custom pistons.

So I did ask my brother about this and he said that he wouldn't go that far. He told me .040 would be as large as he, would go. He knows,more, about it than me as I said he majors in turbo_n/t chryslers and has been working on cars for close to ten years now. he, is very knowledgeable in the turbo side.

So even though I thought .060 might be doable I don't recommend it now. Amd have,to agree with svo. New block and .020.

Quote:

Originally Posted by WES_393

No, the 4g64 isn't made with any thicker walls. 4g64 stock bore size is 86.5mm which is only 1.5mm (.060 over) from 4g63 pistons (85mm stock). It's not recommended to bore the 4g64 much larger unless you have had the cylinder walls check very thoroughly. Plus, I only know of forged 4g64 pistons going to 87mm so any larger and you would likely need custom pistons.

ok cool thats what I thought. Yeah I knew the bore, sizes I just didnt know the streetable bore limit. Thanks bro.

Fotowntalon · 07-11-2012, 07:04 AM

Every block is different, crazy to think how some of us are so stuck to our ways of '.040 is the MAX' without looking to see how crazy far some other platforms have gone

bullettdsm · 07-14-2012, 12:28 AM

OP, it looks like you have a course of action, but yes you can go .060 on these blocks, it has been done successfully multiple times.

Now where I would get the willy's would be using that big of a piston on a stroker and turbo build. Its that much more of a slug and surface area to be throwing around on the end of the rod.

If it was a stocker 2.0 build (one that would just see daily driving and little top end rpm's) I would go .060. Or if it was just a straight strip, low mile, purpose build, I would do it. But for your set-up I would just get another block (as you said you were going to do).

I just didn't like some of the info being bantied about. Good luck with your build.

MB