Gator77
Well-Known Member
What are my options? I was thinking about picking up a 340 that's for sale with out caps is it even worth it thanks for info
I still don't know why anybody would separate main caps from the block. That's just stupid. Somebody sells caps. Try Summit. You have to get the line bore re-machined though.What are my options? I was thinking about picking up a 340 that's for sale with out caps is it even worth it thanks for info
No doubt. Even used caps on that used block should be sent to the machine shop for machining.I know such a easy task to put them rite back on when disassembling
I would imagine they fit the caps to the block and then machine the bores. We should ask @krazykuda. He worked at a Mopar engine plant.How the registers are cut in relation to the cap is the problem there little different in each block, you end up with the cap sitting off set to the main bore. So Machining the register one way or the other to scoot the cap over and then if possible Re swedging/staking them to snap in...then a line hone hopefully is enough...
Anytime though you have to 'line bore' you're definitely going to end up with a chain that's jus a little loose..sometimes even a .010 under chain is loose.
I picked up a '73 340 block for a good price ($100). Realized when I got it home that the caps likely are not original to the motor, mainly based on surface condition. Motor is standard bore and if/when I build it will get a 3.79 or 4" crank but won't be a max effort build. Strong street and road course motor. I realize that I'm going to have to have it line bored now, but is there anything else that I need to look at on them? It there any benefit to a set made from alloy steel in this type of application? I can machine and grind a set pretty easily and they'd get honed anyway.
If you don't have any caps, FABO member Rocket is selling the best caps out there (IMO) and you get all 5 caps if you buy from him.
The three center caps are 4 bolt caps, but you can cut the out bolt bosses off of them a go.
If I needed all 5 caps that's what I do. They are the caps that came on the R blocks.
How the registers are cut in relation to the cap is the problem there little different in each block, you end up with the cap sitting off set to the main bore. So Machining the register one way or the other to scoot the cap over and then if possible Re swedging/staking them to snap in...then a line hone hopefully is enough...
Anytime though you have to 'line bore' you're definitely going to end up with a chain that's jus a little loose..sometimes even a .010 under chain is loose.
And if you read my post again and use a little bit of imagination ...picture snapping in the wrong main cap in a block and there's about a .020 lip of the cap main bore over hanging on one side and under hanging on the other...I would imagine they fit the caps to the block and then machine the bores. We should ask @krazykuda. He worked at a Mopar engine plant.
And if you read my post again and use a little bit of imagination ...picture snapping in the wrong main cap in a block and there's about a .020 lip of the cap main bore over hanging on one side and under hanging on the other...
The registers hold them that way...so you have to scoot them over, file, swedge... however you have to... just remember the bore and bolt holes will pretty much be spot...but not if the register were cut diff..and they are by a hair 90% of the time... then its off to one side and nothing lines up. I worked in a machine shop and line honed blocks, resized rods, straighten rods, cut and installed seats, ran the mill, sunnen ck 10 honed a number of blocks.
Btw ask karl all you want, wont change ****.
Brutha I hear you, exactly...and that's why I told him get a few sets of caps and find the ones that fit 'the closest', that only require filing/cutting the register and staking/sledging the iron over 'to the cap'...milling the caps sides would be last on the list after all else is exhausted. I had a 360 get line honed and studded one time ..and when I got it back the Caps didn't snap in...they just fell in then I checked'em with a bore gauge n was not happy ...some twisted .0003-.0005 I fiddle fkd that cap set for about 2 hours, torque n check torque n checkAnd then, you end up cutting the crap out of the cap if you can't move the cap far enough to get some materiel so you can get the mainline back in.
That's why if you need to replace the caps for whatever reason, you'd better have a bunch to screw with to make sure you have some options.
Or just buy new caps that are far enough undersize so you have something to work with.
I used to save every cap off every block that was broken just so when the need arose, I had something to work with.
Well you guys are the experts. It sounds like you have saved quite a few by matching caps from other engines. I was curious as to how the factory did it. Maybe someone stood around and trial fitted caps and then sent the block to be line bored. May be they just snapped the caps on and then line bored to correct the dimensions. I mentioned Karl because I know he worked in engine assembly. I was just curious as to how they did it at the plant.And if you read my post again and use a little bit of imagination ...picture snapping in the wrong main cap in a block and there's about a .020 lip of the cap main bore over hanging on one side and under hanging on the other...
The registers hold them that way...so you have to scoot them over, file, swedge... however you have to... just remember the bore and bolt holes will pretty much be spot...but not if the register were cut diff..and they are by a hair 90% of the time... then its off to one side and nothing lines up. I worked in a machine shop and line honed blocks, resized rods, straighten rods, cut and installed seats, ran the mill, sunnen ck 10 honed a number of blocks.
Btw ask karl all you want, wont change ****.
I get it.Well you guys are the experts. It sounds like you have saved quite a few by matching caps from other engines. I was curious as to how the factory did it. Maybe someone stood around and trial fitted caps and then sent the block to be line bored. May be they just snapped the caps on and then line bored to correct the dimensions. I mentioned Karl because I know he worked in engine assembly. I was just curious as to how they did it at the plant.
True that but where did the caps go and why. After reading through this thread I don't know if I could trust that the block is any good. Seems like the caps get robbed before the block gets scrapped.I understand, it may be a process to find usable caps for a block they've been lost from. But I wouldn't trash a good block just because the caps were missing or pass one up that was a deal.
True that but where did the caps go and why. After reading through this thread I don't know if I could trust that the block is any good. Seems like the caps get robbed before the block gets scrapped.I understand, it may be a process to find usable caps for a block they've been lost from. But I wouldn't trash a good block just because the caps were missing or pass one up that was a deal.
True that but where did the caps go and why. After reading through this thread I don't know if I could trust that the block is any good. Seems like the caps get robbed before the block gets scrapped.
How the registers are cut in relation to the cap is the problem there little different in each block, you end up with the cap sitting off set to the main bore. So Machining the register one way or the other to scoot the cap over and then if possible Re swedging/staking them to snap in...then a line hone hopefully is enough...
Anytime though you have to 'line bore' you're definitely going to end up with a chain that's jus a little loose..sometimes even a .010 under chain is loose.
I would imagine they fit the caps to the block and then machine the bores. We should ask @krazykuda. He worked at a Mopar engine plant.