boring a vg30 out to vg33 will Not work

[defrag010]

I was dialing in the boring bar today, and testing the replacement 60 degree v6 base to make sure it's true. Threw up an old junk vg30 block, and was on the way to VG33 size to see what wall thickness was like. I got to 3.56" and decided to check and see where it was at. cyl#1 turned out to be about .155" on the thrust side and between .140" and .145" everywhere else. I would hate to bore another .042" out of that, that would make the walls less than an 8th of an inch in some spots.

so, I don't know if there is already documentation on this.. but I see this question thrown around all the time on all sorts of forums, so I thought I'd post up a definite answer... it's going to get THIN!

[Steve88t]

Would you be willing to continue until you found the breakthrough thickness so we can document at least one case of wall thickness?

[defrag010]

Sure! The bore gets thin at the top right below the deck, then tapers down in thickness to the bottom of the cylinder... so if it breaks through any, it will be right below the deck.

If I have enough time, I might see if I can cut all of the cylinder out and see if there is enough meat at the bottom of the cylinder and the deck to knock in a larger wet sleeve. That would be sick, a big bore vg!

[VG36ET]

Steve88t wrote: That idea wouldn't be a big deal if one had access to a machine like you do. But people want so much money just to do basic machine work these days it's hard to justify.

WHat he said.........God forbid if you want some really basic machine work done by a competent person nowdays.....cha-ching! Even the idiots charage an arm and a leg.

Anyway, I have dreams of a sleeved 100mm bore VG, but that'll probably never happen. It sounds like 87.5 is the max bore one would wanna go on a VG30E, for a boosted build or an N/A! I'd love to know the max bore on a VG33E block.

[defrag010]

okay, the VG30 broke through at 3.78". broke through right below the deck. VG30 will be okay to run all the way up to 90mm bore. You might be able to get away with VH45 pistons if you checked to make sure your walls were okay.

VG33 has THICK walls.. they measured out at about .300ish thickness on a stock bore block. You could bore a VG33 all the way up to 99mm if you wanted to and you'd still have 5/32" to 1/8" cylinder walls. That would make it a 3.8 liter!!! haha

You don't have to drop $$ to get machine work done, basic stuff like crank grinding and boring/honing is cheap, but also, cheap can be relative. our shop charges 89$ to grind a crank, and 10$ per hole to bore and 5$ per hole to hone, 50$ to surface each deck... so you could get away with a totally machined block and ground crank for under 300 bucks. Most prices are similar to ours, except for the big name race guys who do machine work, and all you're paying for there is a name.

honestly, if it was my engine.. I'd rather oil the pistons/walls by adding a little more rod bearing clearance with a little more rod side clearance than put squirters in. I hate squirters, they are nothing but a failure point IMO. lots of engines are running high hp w/o squirters, I don't think not having them is a restriction. I always block 'em off, I'd rather have pressure than oil on the bottom of my pistons. I built a 4g63 for a buddy last year with blocked off squirters, and he's running 25 psi on a T88 and hitting high 9's in the 1/4 with no problems.

[Evil Z31]

[quote]VG36ET wrote:

That idea wouldn't be a big deal if one had access to a machine like you do. But people want so much money just to do basic machine work these days it's hard to justify.It sounds like 87.5 is the max bore one would wanna go on a VG30E, for a boosted build or an N/A!

I have 88mm's from Wiseco.


Great post defrag!!!

[Steve88t]

[quote]MachZ wrote:

You don't have to drop $$ to get machine work done, basic stuff like crank grinding and boring/honing is cheap, but also, cheap can be relative. our shop charges 89$ to grind a crank, and 10$ per hole to bore and 5$ per hole to hone, 50$ to surface each deck... so you could get away with a totally machined block and ground crank for under 300 bucks.
You're in Tulsa, right? I may be visiting you some day. :mrgreen:

*edit* It's been pointed out I am a fucktard and forgot defrag was in Tulsa. One of these days soon I would love to see the truck or this block you are cutting up.

Evil, I've got 88mm Ross in mine. I've heard of people doing 89mm in a VG30 but most of that information was years ago and I don't remember where I read it.

[VG36ET]

Uh Yeah......... an N/A VG33 with 12:1 compression(93 octane) and a 99MM bore would be tons of freaking fun and should reach or exceeed the 300 hp mark with all the bolt ons(Russ cam gears, thorley headers, etc., etc.)! I dunno, I'd want thicker cylinders then that, even on an n/a engine with no nitrous.

Defrag - Great post bro. Around here you pay through the nose for top shelf work or you take your chances on joe-blo.

This should definitely be a sticky as the question *How much can you overbore a VG30E and/or 33E* has only be asked on the net five million times! Good work.

[Steve88t]

How about we keep this thread going with some decent info and ideas. Then I'll clean it up in a few days and make it a sticky type thingymicjigger.

Oh and VG36's idea on the 3.8 NA is pimp. That would REALLY be cool.

[phxZ31]

uhh yeah.. I would LOVE a 3.8L N/A VG. Holy shit, that would be my dream Z right there.

Paeco makes a stroker VG. Any idea what could be created with Paeco's crank and rods in combination with a 99mm bore on a VG33?? A 400ZX maybe?

[defrag010]

MachZ wrote:

You're in Tulsa, right? I may be visiting you some day. :mrgreen:

yep, I live over by TU. won't be here for much longer, though, July 31st is my last day in T-town.

I was bored again today, and crunched some numbers and came up with a way to make a 3.8L with off-the-shelf parts. STD bore LS1 pistons, grind the crank so that the rods are an undersize of 2.00 SBC small journal, then get some 6" SBC small journal rods and hone the small end out for the ls1 pins, and narrow the big end to fit on the VG crank's rod throws.... BAM. cool thing about that is you can get shelf parts like forged ls1 pistons and h-beam rods and what not. That's just a daydream, though, usually there are always snags that pop up when creating a frankenstein like that. one I can think of off the top of my head is custom headgaskets that you'd need for the big bore.

for the sake of keeping the topic alive, I'll agree to disagree about oil squirters. People can melt pistons with anything from a bad tune, to too high of intake air temps, to knock, to just not having the right alloy pistons that can take the cylinder pressure. There are tons and tons of road race/endurance engines out there with the right setup and no oil squirters that live up to ungodly abuse. squirters are a good band-aid for not-so-ideal cylinder temp/pressure conditions, but IMO you don't need them if your whole system (engine, fuel, intake) are set up properly. If I was buliding an endurance engine, I would use 2618 pistons that yield a very low compression, give them a little more than usual wall clearance, and have a nice water injection setup on the intake.

[VG36ET]

phxZ31 wrote: uhh yeah.. I would LOVE a 3.8L N/A VG. Holy shit, that would be my dream Z right there.

Paeco makes a stroker VG. Any idea what could be created with Paeco's crank and rods in combination with a 99mm bore on a VG33?? A 400ZX maybe?

You read my mind bro. One of the guys I wheel with was talking about the Paeco stroker kit. With a 99mm Bore on a VG33E and a 89.4MM stroke with their mod'd crank you'd have a 4.13L engine........(insert evil cackle) hahaha!

[defrag010]

how much would you think a 3.8L vg shortblock would go for?

[G-E]

defrag010 wrote: how much would you think a 3.8L vg shortblock would go for?

make one and find out

[SATAN]

[quote]G-E wrote:

how much would you think a 3.8L vg shortblock would go for?make one and find out

Sell for or cost to build?

I am assuming sell for. If I were to put in the time and money and then sell it, with forged internals... $3500 short block only.