Well fellows, this topic is getting very interesting!
And for sure, after all the research is done and if I it all turns feasable, I'll post here the results. This is in fact a long term project, not for me but for a good friend of mine, a guy that loves a lot the 261 and the one that talked to me about this great site!
Chevyman: I see the sleeving process like You described also. I mentioned boring (and sleeving) as a way to see what I'm dealing with. I do not have a sonic tester to check the walls thickness, so only boring them and taking notes on what diameter we reached water jacket will give me a final answer as for the boring limit.
As for the crank, I want to use the 292 rods just because they have a smaller big end, then I'd take advantage of the difference to increase the stroke, in this case, opening the arm .106" for each side, total of .212" increase in the engine stroke.
Also the 261 piston comp height is around 2.000", the 283 is at 1.800", as long as the new stroke is .212" longer, it will take the piston .106" higher in the bore. This will require to shave the deck around .100" to have the compression set back to a level a li'l higher than the 261 had before.
I knew the 292 rods and bearings were a bit narrower than the 261's, but not by how much. Now I know, You told me!
All the 261 cranks here are forged steel, so welding and regrinding them is no big issue to me, the only difference is that I'll have to build up the sides of the rod pins at the crank, in a way that the rods will have a surface to ride on their sides all the time after the crank is done.
I like a lot this process of rebuilding it another way. In the eighties, I mockep up an engine using parts of others here, and the results were rewarding.
We had here 2 L4 chevies, the 153(like the Nova ChevyII of the 60's, 3.875" X 3.250", 5.700" long rod, 2.300" and 2.000" crank pins) and a 151 just like it, except for: 4.000" bore, 3.000" stroke, 6.000" long rod, but the same crankpins,2.300" and 2.000". So I just got a 153 crank and put it in the 151 block using a 5.700"rod. As long as I didn't had a taller 4.000" bore piston(the 151 uses one as tall as a 350 V8) and at that time we were not allowed to import auto parts here, (so I could not get 4 pistons from a 327 engine) I just shaved the deck .100" and also milled .100" from the head, and it was done. There was a fashion here to drop this engines into cehvettes, and by that time the bigger 181 CID was not available.
Also we had 2 types of 250 L6 here, an early version like the ones in US, 3.875" X 3.480", 5.700" rods, 2.300"X 2.000" crank, and a second desing, all the same, except for a 6.000" long rod and a piston with a comp height of 1.340" instead of the normal 1.640" ones.
Well, some wise drag racing fellows knowing that there were no tell tale tools available, decided to do the following: get a 292 crank, grind it down from the stock 2.450" X 2.100" to the 2.300" X 2.100" 250 set up, a set of 5.700" long rods and a set on pistons for the long rod engine, 1.340 comp. height. The result: a 292 low block. Looks kikw a 250, but a 292. Ok, with a rod/stroke ratrio of 1,38/1 it does not spin high, would say that 5.500 rpms are THE TOP, but it has such a ridiculous amount of torque that just made this no revving just a detail. And also, this 1.340" pistons uses a 2mm, 1,5mm and 4 mm ring pack.
Tony: Your comments are pretty cool also.
Both in the Buick pistons and about the bike stuff. As for the bike, ever visited the Ian Drysdale page? They used to run a mailing list, but no longer available, in this list the guys there discussed not only bike stuff but also motor engineering and project. Never found a place where some deep subbjects like engine balancing and other related project itens were so well discussed
. Ian's page is about his bike, a V8 powered suprbike he builts in Australia. Drysdale Motorcicle company. Seriously cool dude, this guy still finds time to reply e-mails from some curious guys from brazil, taht was likely to discover why his bike has a flat crank instead of the 2 planes version. Got really amazed by his projects, the way He project and build his bikes, and of course how he handles it all.
This Buick stuff gave more options, but still has to deal with the pin diameter stuff. But bushing the rod to a floating pin is no big deal.
Kiwi Mike: I also had the option of using the forged 292 piston, but did not want to make it just because of the thicker rings. These pistons have the ring pack way down and also have a very thick head, so milling them to get the right height is no issue either.
I've already had some thoughts about using wet liners, but it may be very well observed. Don't have any idea on the block's bottom end strengh to handle it all. Making it fit is easy, the process is not impossible to be done, but I have no idea on how and if and for how long it will work! I used to assemble some engines with wet liners, and always noticed that the water jacket bottom is pretty strong for the engine size. Both on small pass car gasoline engines and in diesel engines for trucks. At least machining and researching is easy!!
