Largest displacement using TA block?

[TransAm WS6 420]

I heard rumor of a raised cam version of this block that would allow displacement into the 300's. Any truth to this? If not, what is the max displacement for this block?

[1dmbth]

not to sure about that. But we sure could use some more cubes out of the old 6!

[chevyII]

I think 300ci is max.

[750H.P.V6]

I haven't heard of a raised cam version. Maybe Mike from TA can chime in if he's lurking out there. With the current block displacement will be limited to approx 274 cu in with a 3.625" stroke and 4" bore.

Neal

Originally Posted by TransAm WS6 420

I heard rumor of a raised cam version of this block that would allow displacement into the 300's. Any truth to this? If not, what is the max displacement for this block?

[chevyII]

They did advertise a raised cam block I dont know if they made any. The problem with one is this a special timing set which would have to be a belt more than likely. Then there is the issues with the dist/cam sensor drive.
I looked into the same thing with a chevy block and the cutom parts got really expensive and the buick parts would be made to order. I think it could support a 3.700 crank. Also the chevy had wider oilpan rails to clear the rods,so a custom pan was needed.


If a stage 2 alum block costs 20,000-25,000 then the 300CI would top 30,000 easy

[BAGN]

Originally Posted by 750H.P.V6

I haven't heard of a raised cam version. Maybe Mike from TA can chime in if he's lurking out there. With the current block displacement will be limited to approx 274 cu in with a 3.625" stroke and 4" bore.

Neal

Dont quote me on this, but when I talked to mike a year ago or so, I think I remember him telling me that he could go a lot larger then 4.00 bore. If my memory serves me correctly (which it seldom does) I believe it was very close to 300c.i. w/a 3.70 crank and large bore. ?!?!?!?!?!?!?!?!

[750H.P.V6]

Chris,

It was of the belief that the max recommended bore size was 4.00" per TA. Not to say you couldn't go larger but I would wonder what sleeve wall thickness you'd end up with. With what the LS1 guy's are doing I'm sure you could find a replacement sleeve that would allow greater than a 4.00" bore. As far as the stroke goes you'll still run into the a cam clearance issue like you would in a Stage II block. If you were to build an odd fire engine you could probably go with a 3.750" stroke due to the smaller crankpin diameter.

Neal

Originally Posted by BAGN

Dont quote me on this, but when I talked to mike a year ago or so, I think I remember him telling me that he could go a lot larger then 4.00 bore. If my memory serves me correctly (which it seldom does) I believe it was very close to 300c.i. w/a 3.70 crank and large bore. ?!?!?!?!?!?!?!?!

[Nick Micale]

Having been involved in the block design and production from the start, I can say that a raised cam version was never advertised, or even designed for production. The concept was discussed and some checking into the feasibility of doing this was done, but there would be such a limited demand, production has not been considered up until this time.

The "recommended" bore limit is 4" just as Neal stated, and he is right on with the comment about stroke also.

What is being considered for a future run would be a change in the block oiling. Since the design is based upon the Stage II block, oil first goes to the lifters and cam, then to the main and rod bearings.

A study is under way to re-design for priority oiling to send oil first to the bearings, and then to the valve train. This way, oil could be better restricted to the heads and any lifter displacement would not affect oil supply to the mains.

[DonWG]

I went 4.00 on my TA block and the sleeve wall thickness is scary. If your interested on what it ended up being, I can measure it. This time around, since I have to replace the sleeves, I'm going with a 3.930 bore size to give me a bit more sleeve thickness. If you were to go over 4.0 with a TA block you would need to bore the block out to fit larger OD sleeves. I'm not sure how close the oil galleries are to the bores. That would have to be checked out before you bore the block.