[vidguy]

I sent my GTO shortblock down to Paul Carter at Koerner Racing in AZ to get rebuilt. I'll post pics and progress here but hopefully Paul will post his pictures and details of this progress.

I have the GTO up on wood cribs in the garage and plan to rebuild the TH-400 as well as clean up a few things.

Going to try to put all date correct original parts on it as much as possible. I am only missing the water pump and alternator. I may even restore the A.I.R. parts I took off decades ago and put that back on... (maybe)

Garage is a mess of stuff right now due to some remodeling in the house... So I wont post a pic yet..

Plan is a solid stock rebuild with Roller cam.
Block was .060 over. I was set on using the original Dec 66 block.

Paul had it sonic checked and found a minimum of .250 I believe on the thinnest wall. So we determined we can bore it out and go with custom pistons rather than sleeving, which I was prepared to do.

He found the deck a little out of whack and will take care of that.

I had already sent my heads a long while back to Dave at SD Performance to rework the original 670's with his CNC program to lower the compression and port them and set them up for a Hydraulic Roller we just talked yesterday and they will be ready next week.

I am still debating whether to have Paul do my Short block and send it back for me to assemble, or have Dave send him the heads and put it all together for me. I want to do some of the work myself 'cause I like it.. but this year I don't know if I'll have time. Work, thankfully, is pretty busy and I travel a lot.

Likely I'll have Dave send the 670's to Paul, get a roller cam and have Paul assemble everything.. :-)

Paul I'd appreciate it if you went ahead and posted to this thread with pics and details of what you're doing. Here's a few pics of the engine in the plastic engine crate I sent it in.

[gtofreek]

Will post as I go.

[vidguy]

Thanks Paul.

[77 TRASHCAN]

Stock stroke?

[locomotivebreath]

Just a question , but why are folks so hesitant to sleeve a block ? Seems it would add rigidity / strength and possibly head off potential cooling issues due to thinner walls .

[gtofreek]

Noting wrong with sleeving, but it's real expensive, and since there is a sleeve in the block with some kind of lubricant in between the two, a sleeved block, in my opinion, will run slightly hotter than a non-sleeved block. The thinnest cylinder was .203" so it's plenty of meat for .065" over, and a set of custom pistons with rings is about the same as just sleeving the block, but with sleeving, you have the cost of pistons, and rings on top of that.

[HWYSTR455]

I'm getting to a point where I don't have the patience or time to do the assembly anymore. My original reasoning for doing the assembly was two-fold, to make sure it was right, and the learning/fun factor. It's amazing how many shops, well known ones too, give stuff the 'good enough' treatment. (And when many times it's not)

Paul, I wish like heck you were closer to me, I would have you do my next 3 engines. I like the fact that you're precise, professional, and there isn't a lick of 'smoke & mirrors' with your work. Total disclosure provides confidence to the customer, thank you.

Thing with sleeving IMO is that it's hard to find someone that will do it right.

.

[hurryinhoosier62]

Originally Posted by HWYSTR455

I'm getting to a point where I don't have the patience or time to do the assembly anymore. My original reasoning for doing the assembly was two-fold, to make sure it was right, and the learning/fun factor. It's amazing how many shops, well known ones too, give stuff the 'good enough' treatment. (And when many times it's not)

Paul, I wish like heck you were closer to me, I would have you do my next 3 engines. I like the fact that you're precise, professional, and there isn't a lick of 'smoke & mirrors' with your work. Total disclosure provides confidence to the customer, thank you.

Thing with sleeving IMO is that it's hard to find someone that will do it right.

.

VERY true. IF the person sleeving a block isn't well trained, they can turn your block into scrap metal with little effort.

[hurryinhoosier62]

Originally Posted by gtofreek

Noting wrong with sleeving, but it's real expensive, and since there is a sleeve in the block with some kind of lubricant in between the two, a sleeved block, in my opinion, will run slightly hotter than a non-sleeved block. The thinnest cylinder was .203" so it's plenty of meat for .065" over, and a set of custom pistons with rings is about the same as just sleeving the block, but with sleeving, you have the cost of pistons, and rings on top of that.

.203? That's thinner than I like to see.

[tempest1964]

What do you feel is a safe minimum wall thickness in general and on the thrust side of the bore in particular? I have a block that will need machining one of these days.
Thanks

[Gator67]

Originally Posted by gtofreek

Noting wrong with sleeving, but it's real expensive, and since there is a sleeve in the block with some kind of lubricant in between the two, a sleeved block, in my opinion, will run slightly hotter than a non-sleeved block. The thinnest cylinder was .203" so it's plenty of meat for .065" over, and a set of custom pistons with rings is about the same as just sleeving the block, but with sleeving, you have the cost of pistons, and rings on top of that.

Interesting. I've always assumed that an engine would run cooler with more meat, and so as a general rule, I though it would be preferable to sleeve if only one or two needs it rather than going over on them all. It never occurred to me that a sleeve by itself would increase running temps.

[vidguy]

The sleeving is expensive is all, but I was willing to do this.
I am comfortable with Paul's assessment of the wall thickness in this case. Not as much as you might want but more than many people have run with these motors. The car is not going to be beat on.

[68azbird]

Paul did a sleeve in one of the engines I built. I would bet $1000 to anyone that they can't pick out what cylinder it is by looking at the block. Engine has been running and driving past 2 years with no problems.

[TedRamAirII]

Originally Posted by Gator67

Interesting. I've always assumed that an engine would run cooler with more meat, and so as a general rule, I though it would be preferable to sleeve if only one or two needs it rather than going over on them all. It never occurred to me that a sleeve by itself would increase running temps.

Pontiacs run hotter than other motors because of all the "meat". Its not that much of a issue with a cooling system that's up to snuff, but they all have one hell of a "hot soak" Watch any temp gauge after a good drive and it will make you cringe. I would rather not know about it. ; )

[gtofreek]

Originally Posted by hurryinhoosier62

.203? That's thinner than I like to see.

That's a lot thicker than any other Pontiac block I have sonic checked. I checked a 1960 389 block and it wasn't as thick as this thing is. I have had engines run fine at .125" walls. It just depends on where it's thin at. These cylinders were real thick down low[.320"-.407"]. The thinnest spot was near the top of one cylinder.

[hurryinhoosier62]

Originally Posted by gtofreek

That's a lot thicker than any other Pontiac block I have sonic checked. I checked a 1960 389 block and it wasn't as thick as this thing is. I have had engines run fine at .125" walls. It just depends on where it's thin at. These cylinders were real thick down low[.320"-.407"]. The thinnest spot was near the top of one cylinder.

OK. If it was .203 down low, I'd be looking for a new block. Isn't the '67 400 block supposed to be one of the "holy grail" blocks?

[GRX]

Originally Posted by hurryinhoosier62

OK. If it was .203 down low, I'd be looking for a new block. Isn't the '67 400 block supposed to be one of the "holy grail" blocks?

Grail may be a bit excessive. Nickle hype aside, they are good blocks. Eyebrow location on the '67 HO blocks is a concern.
Speaking of sleeves ...

[77 TRASHCAN]

Originally Posted by GRX

Grail may be a bit excessive. Nickle hype aside, they are good blocks. Eyebrow location on the '67 HO blocks is a concern.
Speaking of sleeves ...

You get your 428 build back to the front burner yet?

[hurryinhoosier62]

Paul, Bud always told me .180 on the thrust side was the thinnest cylinder wall that he (along with Grumpy Jenkins) was comfortable with in a street engine UNLESS the block was filled. What are your thoughts?

[hurryinhoosier62]

Originally Posted by GRX

Grail may be a bit excessive. Nickle hype aside, they are good blocks. Eyebrow location on the '67 HO blocks is a concern.
Speaking of sleeves ...

"Holy Grail" was tongue-in-cheek. You know the type.."You CAN'T build a decent engine without THIS block".