4X151981 Block Casting

[750H.P.V6]

Guy's,

There is one of these blocks currently for sale on Ebay and Racing Junk.com. I know it's a GM experimental casting and seems to fit onto the Stage II evolution between the last Off center blocks and prior to the On center blocks.

Since the block is in AZ and not far from my friend Rick Elam I asked him to check it out for me. He sent some pics which I'll include. The block appears to be an Off center casting which has been machined On center (check the pics you'll see what I mean). As such I'd expect the cylinders to be very thick on one side and thin on the other.

This brings me to my question: Has anyone had first hand experience with one of these blocks and did you have it sonic checked? If so what did you find? Any info would be great.

Thanks

Neal

 

[laz]

Looks to be a weird casting it does seem based on a stage 2 cause of the oil pickup but unless you get a smokin deal i wouldn't gamble . I thought all the old casting where off center a few i worked with where very thin bores not much support the on center are really thick so i wouldn't be scared to let it have it , if its a mild engine then go for it .

 

[750H.P.V6]

Laz,

Thanks for the input. For right now I'm going to pass. The guy selling is a "Chevy guy" and seems to be speculating. From what I can tell he doesn't need the money either. I was hoping Mike Booher or Ron Tarabori might chime in. I'm pretty sure Ron had at least one. Mike seems to have had one of everything so I'd be shocked if he hadn't owned one at some point. If the guy would agree to have the block sonic checked it might help determine if ti's usable in a high H.P. application or not.

Neal

 

[forcefed3.8's]

Since the deck is off center, but the bores are on center, how would the head gaskets and chambers line up. I would imagine the head bolts are still positioned like the cylinders were bored for off center. Weird stuff.

 

[Mike E]

Since the deck is off center, but the bores are on center, how would the head gaskets and chambers line up. I would imagine the head bolts are still positioned like the cylinders were bored for off center. Weird stuff.

The pics on ebay show that the front of the block is machined like an on center block. I would bet the head bolt holes are shifted also.


Looks like all the machining is just like an on center, but machined from an off center casting. But, it could have had a special water jacket core, hence the special casting number. Without sonic test numbers, who knows.

 

[750H.P.V6]

Looks like all the machining is just like an on center, but machined from an off center casting. But, it could have had a special water jacket core, hence the special casting number. Without sonic test numbers, who knows.

Mike,

My thoughts exactly. From looking at the bottom of the cylinders it appears that the machining has been shifted forward on one bank and aft on the other. I might call the guy back and see if he's opposed to the idea of a sonic check. I tried to contact a friend of mine that I believe had one of these blocks to get his input. I'll let you know what he says.

Neal

 

[KendallF]

Yep, I had one of those, back in the day (whatever my day was..). Mine was blown up and so I had the "opportunity" of sleeving the front two bores. I didn't sonic check it but I did bore the front two cylinders for the sleeves and didn't hit the water jacket on either side.. and that was .187" over according to my old notes here:

http://www.secondhandsix.com/ttype/block.htm

The head bolt holes, intake end rails, etc. lined up for on-center stuff just fine. I'm trying to remember any other weird points about it, but can't recall any right now.

I don't see any bites at $3500...what's a bare TA block go for now, anyway?

 

[750H.P.V6]

Kendall,

Thanks for the input and the link to your old site. It's good info and I appreciate it. I did speak to the guy a day or so ago and he wasn't opposed to the idea of doing a sonic check of the block. I guess we'll see what we find.

Neal

 

[turbodave231]

Neal,

I had a new 4X159181 block that I sold many years ago. I have another one of those block in my current collection of stuff. It threw rods in #1 and 2 and beat up the bottom of the cylinders. I magged the block and didn't see any cracks, so I think I can save the block with 2 sleeves. My plan is to use it for a short stroke long rod N/A carbed setup run on E-85. That way I can use one of the Busch cams and gear drive parts I have lying around. I just need a light car to put it into. A V6 Monster Miata might be cool!!

 

[750H.P.V6]

Dave,

It sounds like there might have been a few more of these blocks than I originally thought. With the one you have currently does it exibit the same offset machine work? I would suspect it does. Have you done a sonic check or do you plan to before you use it? BTW, I like the idea of a high compression aspirated motor on E-85 in a light weight car. I contemplated the same thing last year when I bought a couple of ex-road race engines that were fresh. A monster Miata with a V6 would be cool especially with Kinsler injector stacks sticking thru the hood!

Neal

 

[turbodave231]

I'll take a closer look at the block tomorrow. I never looked that close at the bores and how they were machined. I see now that the oil feed tower on the front of the block is just like what you posted. Looks like an offcenter that was machined away. I also had a very early 153 block that had the oil tower that look just like an offcenter block. Not machined at an angle. Ron Tarabori ended up with that block. The ears were cut off the bellhousing for use in an Indycar chassis.