will it hurt. whats your opinion

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trudysduster

trudysduster

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I dont know anything about this other than to get the cylinders bored and I dont want to go that far but I have a small ring wear at the top of the cylinder. I am going through this engine trying to keep it home to the original car. It is a 66 Valiant. slant 6. replacing rings, rod and main bearings, and after I got down this far I am replacing the camshaft, lifters. My question is I am going back with the same pistons. Will that ridge at the top be ok. I cant see that the new rings will get into it OR what is your opinion about using a ridge reamer to cut that ridge out. I have read both pro and cons about this and have never done it. If used will I lose compression. If I dont will the new rings hit the ridge and cause a problem. let me know what you think.
 
Rings will hit ridge. Not good. Use a ridge reamer. It should only cut the ridge.
 
I don't see how the rings would hit the ridge when everything else is the same. BUT, you need to get rid of the ridge so you can remove the pistons without harming them. That's my take anyway. I am not a machinist by any means.
 
People have been doing rerings for almost a century without major issue. Is it optimal? No.
Fresh hone, new rings, bearings etc.
But, once you are into it as far as cam and cam bearings, you really need to evaluate how much you want to be into a rering vs a full rebuild.

Are you doing anything with the topend (cylinder head)? If you rebuild the head you are almost at the stage of putting lipstick on a pig.
 
how far do you want to get into this engine ?

if you rip it out, and deck it 0.250 will that be a double edged sword that gets rid of the ridge?
 
I always remove the ridge if I can catch a fingernail on it.
 
Which if so won't be enough to mean much besides making up for the thicker than oe head gasket. People go 0.100 each on head and block with the/6. I went 0.100total between head+block and penciled out exactly at the blueprint spes.
Then again I never saw anything to say whether he's doing a 170 or a 225. If170 it'll be closer to zero deck as is than if it's a 225
 
diymirage said:
Sure is, maybe I got my numbers wrong, but it's a slant 6 right ?

They need quite a bit of help to get some compression going
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Yes, slant 6. 1/4" is doable, but split between the head and block.
 
Bodyperson said:
Offset grinding the crank is a good way to increase compression.
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It is, but unfortunately, the pistons sit around .175" or so in the hole at TDC. That's a lot of offset. lol
 
Bodyperson said:
Just trying to work within what seems to be the OP's budget.
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I'm not disagreeing. It'll work, but what's he use for rod bearings? He's gonna have to have the big end of the rods resized to a different journal size and use a rod bearing for a different application. We're not talking about a .025" offset here. I get what you're saying, but offset grinding is more expensive than grinding back to standard stroke, plus now he'll have resizing the rods to pay for. What's "budget" about that? Some of the more popular crankpin resizing applications are Chevy and Honda, but because of the extra machine work involved, "budget" is kinda not there anymore. Besides, the 225 already has a 4.125" stroke. To get zero deck height, you've gotta offset that bad boy to beyond 4.250". That's a lot. Just spitballin......I wonder how much of a dent he'd put in some Molnar rods and Wiseco pistons doing the machine work to offset grind the crank? It'd be worth looking into. The bigger question is, is he even remotely interested? I'm thinking probably not. Not for what he's doing anyway.
 
RustyRatRod said:
I'm not disagreeing. It'll work, but what's he use for rod bearings? He's gonna have to have the big end of the rods resized to a different journal size and use a rod bearing for a different application. We're not talking about a .025" offset here. I get what you're saying, but offset grinding is more expensive than grinding back to standard stroke, plus now he'll have resizing the rods to pay for. What's "budget" about that? Some of the more popular crankpin resizing applications are Chevy and Honda, but because of the extra machine work involved, "budget" is kinda not there anymore. Besides, the 225 already has a 4.125" stroke. To get zero deck height, you've gotta offset that bad boy to beyond 4.250". That's a lot. Just spitballin......I wonder how much of a dent he'd put in some Molnar rods and Wiseco pistons doing the machine work to offset grind the crank? It'd be worth looking into. The bigger question is, is he even remotely interested? I'm thinking probably not. Not for what he's doing anyway.
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Chevy rods sure seem to be the "go to " any more. Ya you are correct, busting the budget here.
 
Bodyperson said:
Chevy rods sure seem to be the "go to " any more. Ya you are correct, busting the budget here.
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Yeah and I've never been a big fan resizing a crankpin "just to do it". I've seen more than my fair share of cranks broken at the rod journal. I'll leave mine "big and heavy". lol
 
Bodyperson said:
I don't see how the rings would hit the ridge when everything else is the same. BUT, you need to get rid of the ridge so you can remove the pistons without harming them. That's my take anyway. I am not a machinist by any means.
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Because the new rings will have a sharper edge than the worn ones that formed the ridge, that can result in cracked rings, or a pushed top ring land pinching the 2nd ring.
 
I may not know suspension well, but motors I do lol. Two options for a ridge, either cut it or have it bored which will change your piston and rings. Seems you are so far into this build already you might just as well do the rest. The guys aren't wrong on cutting the head some either or running thinner head gaskets to increase compression. Worth a call to a local engine shop.
 
You guys are getting way off course here. My question was what are your thoughts about using a ridge reamer to cut the ridge out. I was told by a friend who used a ridge reamer that he lost compression I guess because he used the reamer and apparently he didnt use it properly. Is it necessary to cut the ridge and will the new rings hit the ridge if I dont. I am not decking the block. The head is in the shop doing the valves and I am only shaving the head just enough to true it up.I done my 76 engine the same way 6 months ago but didnt have any ridge to cut and it runs fine.
 
trudysduster said:
You guys are getting way off course here. My question was what are your thoughts about using a ridge reamer to cut the ridge out. I was told by a friend who used a ridge reamer that he lost compression I guess because he used the reamer and apparently he didnt use it properly. Is it necessary to cut the ridge and will the new rings hit the ridge if I dont. I am not decking the block. The head is in the shop doing the valves and I am only shaving the head just enough to true it up.I done my 76 engine the same way 6 months ago but didnt have any ridge to cut and it runs fine.
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Get used to it. They can make a mountain from a mole hill.
 
trudysduster said:
You guys are getting way off course here. My question was what are your thoughts about using a ridge reamer to cut the ridge out. I was told by a friend who used a ridge reamer that he lost compression I guess because he used the reamer and apparently he didnt use it properly. Is it necessary to cut the ridge and will the new rings hit the ridge if I dont. I am not decking the block. The head is in the shop doing the valves and I am only shaving the head just enough to true it up.I done my 76 engine the same way 6 months ago but didnt have any ridge to cut and it runs fine.
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I don't think it would hit the ridge if it were installed, but I have no idea how you would get the piston and rings back in the cylinder with the ridge there.
 
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