Machine shop

[Twisted6]

Sending the engine off to the machine shop soon, did search a bit, but the information seemed scattered and inconsistent. I was wondering what is recommended and what is not recommended for machine shop work on the block, heads and crank?

 

[sperold]

Need a little more information.
As a general rule, do as little machining as possible. This is not a 305 Chev which would need everything machined, just to make it correct.
Leave the crank alone if possible.
The block will not need any machining.
The heads can be left alone as well.
Most people use stock bores and standard rings

 

[Phoenix]

Leave the crank alone if theres no scars or burrs. If you want a full rebuild , this is what I do:

Replace rods and mains bearings , LIGHTLY hone the cyl. , clean pistons and change the rings.

With that you will get zero surprises. and zero oil consumption.

 

[Lorenr]

That is very good advice

And if you really want it to fly, hand lap the valve seats with valve lapping compound. Use new valve stem seals.

If you are rich, do a three angle valve job. DO NOT sink the valve seats while doing this. A good valve job might actually be worth 5 horsepower.

 

[Phoenix]

And if you really want it to fly, hand lap the valve seats with valve lapping compound. Use new valve stem seals.

If you are rich, do a three angle valve job. DO NOT sink the valve seats while doing this. A good valve job might actually be worth 5 horsepower.

Good advice , If you do it , your shims wont fit anymore and your will need wierd sizes all over the place.

Been there , done that. if they are in good shape , just compound it.

 

[AREA 91]

Unless I am installing aftermarket pistons, I recomend NO machine work.

 

[SHOstopper1992]

My buddy is getting the same thing done to his 73 Beetle. The one thing I can say is make sure you break the motor in correctly.


Considering this is about machining, 2BadSHO's told me a while back that people were making 3.6L SHO's and 3.3L Motors? Is this true and is this possible?

Yes I know I am speaking of a serious modification and extensive work.
What all would it take to do all that?

 

[jonheese]

Considering this is about machining, 2BadSHO's told me a while back that people were making 3.6L SHO's and 3.3L Motors? Is this true and is this possible?

Yes I know I am speaking of a serious modification and extensive work.
What all would it take to do all that?

The SHOShop did tout the ability to bore out the SHO block to 3.6L, yes. But I don't know how many (if any) they actually made, and how many of those (if any) actually ran for any appreciable period of time.

I think John Hrinsin (or was it John Miller?) had a 3.4L bored-out block in his track car.

I think it basically takes very careful machining (preferably with ultrasonic thickness checking ahead of time), custom pistons, and a decent tune to account for the increased displacement/load.

 

[92sho16]

The SHOShop did tout the ability to bore out the SHO block to 3.6L, yes. But I don't know how many (if any) they actually made, and how many of those (if any) actually ran for any appreciable period of time.

.

They actually cut and rewelded the crank to increase the stroke. From what i remember none of the engines made it that long.

 

[SHOstopper1992]

I think John Hrinsin (or was it John Miller?) had a 3.4L bored-out block in his track car.

I think it basically takes very careful machining (preferably with sonic thickness checking ahead of time), custom pistons, and a decent tune to account for the increased displacement/load.

3.4L? Dang... I want to eventually one day build a 3.2L up to a 3.3L or 3.4L before I die... I eventually wanna AutoX my SHO... thats why I wanna do it.

 

[jonheese]

They actually cut and rewelded the crank to increase the stroke. From what i remember none of the engines made it that long.

Aw crap, I forked up. John's was a stroker block too.

Please disregard my post earlier in this thread.

I don't know if anyone's successfully bored out the block much more than 3.2L. I remember a thread earlier this year about how much meat was left in the different SHO blocks (early 3.0L, late 3.0L, 3.2L), but I don't remember the theoretical maximum that was bandied about, so I won't take a guess and risk 2 mistakes in one thread.

 

[jonheese]

Aha, here it is:
http://www.shoforum.com/showthread.php?t=104318

Boring a 3.0L block to 3.3L (which is reportedly possible) would be a ~.184" overbore (from 3.500" to 3.684") which leaves roughly .104" of wall left.

Extrapolating further, boring a 3.0L block to 3.4L would be a ~.239" overbore (from 3.500" to 3.739") which leaves roughly .077" of wall left.

Disclaimer: The "how much is left" numbers above are based on Jthod's ultrasonic measurements on his 3.0L block in the above-referenced thread, and are only as accurate as his measurements.

 

[Rubix]

Kirk has a 3.3L car for sale, buy it. Someone else on here has a 3.4L that was at the 09 Convention, can't remember who it was.

 

[jonheese]

Someone else on here has a 3.4L that was at the 09 Convention, can't remember who it was.

That was probably John Hrinsin, but could've also been John Miller. Hrinsin has a '95 MTX with a 3.4L stroker and Miller has a 3.6L stroker.

Quoting John Miller (JEM) from http://www.shoforum.com/showthread.php?t=56611 about his 3.6L engine:

3.2 block sonic-checked and bored to 3.75in. Crank offset-ground to 48mm rod journals. Custom pistons, Manley SBC circle-track rods, Honda bearings. Worked-over heads, the first set of +40 cams done (with the extra displacement they should matter), Aussie valvesprings. Stock valves (had to stop shaking the piggy bank somewhere.) Funky reworked 3.2 head gaskets (remove stock fire ring, crimp on 305 Chevy fire ring...) courtesy of the charity of strangers. In progress for about two years, builder ought to be doing final assembly about...this week.

John Hrinsin himself doesn't appear to have ever been a forum member (someone correct me if I'm wrong here), but he was a very active SHOTimes mailing list member back in the day (when it existed and was active). Do a search for his last name here and you'll find a lot of references to his stroker 3.4L engine as well as some other stuff he touched. IIRC, he works/worked for Mr. Gasket/Accel and was a big trailblazer for the aftermarket on the SHO V6.

Also see Sean Simons (GeekSHO)'s thread, page 1 and page 2 for more info on theoretical boring/stroking limitations (my math appears to have shifted a bit since then, oddly enough ).

 

[Twisted6]

Someone stated they needed more information. The engine is a 92 3.0L, roughly about 94K on the engine. Looks like it never got the 60K service, everything looks original. Here is the basic list of services the machine shop offers:

Head Work:
- Valve job - includes clean
- Seals Only
- Wash
- Surface
- Grind valves
- Grind seats
- Hard exhaust seats
- Magnaflux

Guides:
- Check
- Replace
- Knurl, cut for seals

Crank work:
- Grind
- Polish
- Magnaflux
- Wash and check only
- Straighten
- Balance
- Special grind

Block Work:
- Press. Wash
- Bake
- Bore
- Deglaze
- Line hone
- Deck
- Magnaflux

Rods and Pistons:
- Wash and check only
- Recondition
- R&R bolts
- Fit pins/bushings
- Press pistons
- Magnaflux

Misc Work:
- Disassemble
- Reassemble
- Balance

 

[SHOtimer]

When I had my 3.2 rebuilt, all they did to the heads was pressure test them to make sure everything was good (which it was) and I had them replace the valve stem seals.

The block they disassembled and hot tanked, they replaced all the freeze plugs and gave it a slight hone. They only polished the crank.

I re-used the pistons and rods. All new bearings (mains/rods) and rings.

I have almost 70k on it. Runs great and hasn't burned a drip of oil.

Doug

 

[SHOtime2511]

Why not just pick up a good used engine and use that.

 

[SHOtimer]

Why not just pick up a good used engine and use that.

Where's the fun in that? It is much more practical - I'll give you that.

I just loved turning the key on a fresh motor.

Doug

 

[shomethe$$$]

What about the myth of the 95 block having thicker walls, I'm always looking out for one so I'm hoping to report back to put an end to this myth.

Also, does anyone know what engine code I would be looking for to find a true 95 block, the number is on the back valve cover but where else?

 

[jonheese]

What about the myth of the 95 block having thicker walls, I'm always looking out for one so I'm hoping to report back to put an end to this myth.

I'd always heard it was '93-'95 3.0L blocks were thicker than the '89-'92 3.0L blocks, the logic being that they cast a new thicker version of the 3.0L block so it could be easily bored out to 3.2L for the ATX, which of course started in '93.

Also, does anyone know what engine code I would be looking for to find a true 95 block, the number is on the back valve cover but where else?

The only identifying numbers I see on my engine (on a stand in the garage) are:

1.

The sticker on the rear head, which has the printed number (my '90 block says "XA 950 BA"), as well as numbers and letters punched out like some kind of sequence number (mine has "D 2 6" punched), and

2.

The number cast into the rear (right) face of the block (mine says "930 172").