I got a call from the machine shop about my 8BA today. They said the block has no cracks but it has been bored 40 over with a taper of 10. My question is, is it safe to bore bigger then that? Am I better off sleeving the block back to original bore? Will I have overheating problems if I bore that big? This is my first flatty rebuild and I am trying to do as much of a budget rebuild as possible.I just want to do lot's of homework before I jump into anything. I need some help from the Flathead gods on the HAMB PLEASE!!! Thanks, James
Mines bored .080 over, i've been told you can go .120 if you sonic check the cylinders for casting flaws.
You should be fine going to 60 over. I did, haven't had a problem. Don't you trust your machine shop? If not, take it to someone else. A cheap re-build ain't good, and a good rebuild ain't cheap. Especially on a flattie.
Yeah my Pop's and some of my buddies have had alot of motors done by these guys but no flatty's. When I say budget I mean I'm gonna do alot of the ***embly work and try and reuse stock parts if possible. I have no problem spending the money on machine work and quality parts. It sounds like 60 should be fine according to everybody that responded and that's why I asked thanks alot everybody.
mine is bored .125 over, so was the last one I had, NO problems on any of them. if you are gonna go, go balls deep! I dunno about your machine shop there, but the one I use here in good old Milwaukee charges the same if it's .40 over or .125 over, the pistons shouldn't be that much of a difference in price....just checked the Speedway catalog, NO difference on the 3 ring pistons across the board, the 4 ring Grants are $70 more, building an engine is not cheap either way. Good luck. Sincerely, Cheatercarl
My 59ab was already bored .125 over (276 cubes with a 4 inch stroke crank) had to go .145 over using EGGE 3 11/32 pistons and Hastings rings doing my recent rebuild. I now have 281 cubic inches. You should have no problem going .060 or .080.
For whatever it's worth, we have a brand new set of 8BA pistons (.080" os) and matching set of 80 over rings that we brought in for a customer. The deal fell through. I am sending them back for credit, but if I have to pay the shipping to send them somewhere, I may as well give the shipping cost away to another buyer. If you are interested in them, speak up real soon as I am ready to send them back next week. The set of pistons went for $249 and the ring set for $65. That's $314 total...no freight. My offer is to any USA location................. Mac VP
Yup, .060 over is very common with no problems, go for it. The flathead gods are already on your side because a no-crack flattie is rare indeed! Good luck,man!
Hi Jim, have them take it to .060", you'll be fine! You may want to ask them if they have a block-plate to finish hone the bores? Through the years most rebuilds have been done without it, but it's a 100% improvement with respect to "ring-seal". If you are "lucky", you may get pistons very close in weight and avoid a "re-balance", it's a long shot, but sometimes it happens! Save the old pistons for a weight comparison against the replacements! (Add) You want to avoid the "8-sleeves" deal, this operation will toss your "budget-build" right out the window! Thanks, Gary in N.Y. P.S. If they don't have the plate, not many shops do, ask them if they would be willing to at least use some 7/16" "bolts & washers" and torque them down when final honing?? Not the best method, but better than no plate at all! The fasteners will "stress-up" the head bolt threads at least.
Red's Headers used to rent flathead torque plates. .060 is nothing for a flathead. .125 is very common.
Back in the day, if you set up the boring bar and paid the fee you went at least 1/8 over. My 8BA is a 286. You don't have a hair on your *** if you don't go at least to 276.
Whats a good price on a Bore Job I have a guy down the street that want 45 clams to do a jug? And still need to find a price and place on Babbit . My motor in my 33 is tired and kinda deciding keep it or find a newer one. Is Speedway a good place for flatty rebuild goodies?
Hey John, I have newer blocks if you need to go that route. Mike Lange might have some early ones. That dude in Skoki, IL that does the Model A engines, he's a real good babbit guy I thought. Holla at me *******, oh yeah, I have your 3 speed done & collecting dust, when is the next Grays Lake show? I could bring it if you still want it. I aslo have the ***le for your Model A coupe. I have some lotion for your knees too!
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