Allan Faust Posted May 31, 2007 Report Posted May 31, 2007 Ok, Here goes..... I have a Canadian 25" block..... Std Bore is 3 3/8 inches. I purchased a set of pistons.... 0.030 oversize, but for a 3 7/16 inch bore engine.... Now I've heard of people saying that these engines can take the bore up to 0.100, but when discussing with my machinist, he says he can do it, but he doesn't necessarily want to because he says that it may be too much for the engine..... Any comments???? Has anyone ever gone this far with it? I know that Pat purchased the same pistons for his engine (which should be the same as mine....) so I just want to make sure I will go ahead with this..... Allan Quote
55 Fargo Posted May 31, 2007 Report Posted May 31, 2007 Allan, all Canadian L head 6 blocks were cast in Windsor Ontario since 1937. They were used for P,D,C,D, are they all the same casting, I would think so, so if that be the case, you should be able to bore to the sized you have mentioned, if all is the same, ie the blocks. The Chrysler 251, was a 3 7/16 bore and a 4 1/2 stroke. If these blocks were all the same, you should be good to go. The difference betwen the engines was crank, stroke and bore, but I think the blocks were all the same, made in the Chrylser engine plant in Windsor...Fred Quote
Plymouthy Adams Posted May 31, 2007 Report Posted May 31, 2007 Allan..these engine has real metal in them...even engines of the 70-80 had enough metal for a .030 bore and still run cool..now granted in some of the later block of today..some cannot be bored as much..lighter casting for lighter cars. What age is this guy? If he is young he may not have any experience with real cast iron and is drawing only from his knowledge of today's iron..and yes a good achinist will only take off what needs to be done to clean the bore to the least oversize available keeping the block servicable for another future clean up. As mentioned above..the bore fo these block was the difference..will be an easy job...plus you hve the istons and ring in hand for a hone fit..cannot see the problem doing what the "owner" wants. Quote
Allan Faust Posted May 31, 2007 Author Report Posted May 31, 2007 Thanx guys.... Fred, I agree with you that all the blocks in Canada were the same size, that for me wasn't really the issue, but as you mentioned Tim, I think the issue is the "young guys" experience with real cast iron, since he was worried it'd be too thin (his words) and he didn't want to take responsibility for it.... as for the work, he said he could do it... would just take 3 runs rather than one on the machine... but it could be done..... Allan Quote
Plymouthy Adams Posted June 1, 2007 Report Posted June 1, 2007 tell him to chuck up the boring bar and let the big dog eat.... Quote
martybose Posted June 1, 2007 Report Posted June 1, 2007 When we were evaluating my 230 block for what turned out to be a .072" overbore, my machinist used an ultrasonic tester to check each cylinder at the top, middle and bottom of the bore, taking measurements every 90 degress at each location. that works out to be a total of 72 measurements, and all of them were well over the .100" that he considered to be a minimum acceptable finished thickness. If the folks more familiar than I with the big block are correct about the common casting for all variants, I'd bet that you won't have a problem. Marty Quote
DAVE KNOXX TENN Posted June 1, 2007 Report Posted June 1, 2007 Ok,Here goes..... I have a Canadian 25" block..... Std Bore is 3 3/8 inches. I purchased a set of pistons.... 0.030 oversize, but for a 3 7/16 inch bore engine.... Now I've heard of people saying that these engines can take the bore up to 0.100, but when discussing with my machinist, he says he can do it, but he doesn't necessarily want to because he says that it may be too much for the engine..... Any comments???? Has anyone ever gone this far with it? I know that Pat purchased the same pistons for his engine (which should be the same as mine....) so I just want to make sure I will go ahead with this..... Allan Your Block is solid It will take it.BOOM !!!! I KNOW IT WILL ITS NOT MADE FROM RECYCLED METAL!!!GET HER DONE!!! YOU HAVE A VERY SOLIDBLOCK!!!! GET HER DONE!!!! Quote
Allan Faust Posted June 1, 2007 Author Report Posted June 1, 2007 Well, I told the machinist that when we go ahead to let the big dog eat.... Boom... gonna get her done..... !!!! Allan Quote
Mick Blake Posted June 1, 2007 Report Posted June 1, 2007 Allen, I had my 1954 Canadian Plymouth block done 0.090 thou over, I hav"nt had any problems. Quote
Allan Faust Posted June 1, 2007 Author Report Posted June 1, 2007 Allen, I had my 1954 Canadian Plymouth block done 0.090 thou over, I hav"nt had any problems. I just wanted to be sure.... when it comes to me, I'll put my trust in people that know what they are talking about (like people do with me when I know what I'm talking about... which ain't often... ) and the machinist kinda took me off balance when he called.... so I thought I'd re-iterate here.... to be sure... and since I trust the guys here... well, the machinist is doing what the "owner" wants.... it'll cost me more, but a hell of a lot less than buying another set of pistons and rings.... Allan Quote
DAVE KNOXX TENN Posted June 2, 2007 Report Posted June 2, 2007 I just wanted to be sure.... when it comes to me, I'll put my trust in people that know what they are talking about (like people do with me when I know what I'm talking about... which ain't often... ) and the machinist kinda took me off balance when he called.... so I thought I'd re-iterate here.... to be sure... and since I trust the guys here... well, the machinist is doing what the "owner" wants.... it'll cost me more, but a hell of a lot less than buying another set of pistons and rings....Allan GET HER DONE!!!!!! Quote
Dodgefran Posted June 2, 2007 Report Posted June 2, 2007 I'm having my 25 inch rebuilt. It had to be bored out sixty over to get rid of the slight warp in the cylinders. Quote
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