Bore ridge cutting??

[physcult]

Id be interested on peoples thoughts on this. Thanks in advance for any comments.

Im aware that if there is a ridge on the bore, to do the job properly a re-bore is in order. In my case Im just putting the engine back together for the time being. Until I get a new short block. The ridge is very slight.

So far Ive been told:
Dont remove the ridge, its very slight. Removing the ridge will just make things worse. Just de-glaze. (mechanic)

You must remove the ridge, if you dont remove the ridge the (brand new) top ring may damage straight away. (piston ring shop)

If necessary is it possible to remove the ridge carefully using a cylinder hone? Or is this just unnecessary wear and deformation to the cylinder bore?

[eeb43]

ridgedodgers

[physcult]

ridgedodgers
Do they they make these type of rings suitable for a supercharged engine.

[kc]

in the good old days when people rebuilt daily stuff and the country was littered with engine reconditioners they used to fix the problem with a device known as a ridge reamer ( im sure there is a joke in there somewhere... ) but that became redundant when piston ring sets were introduced with a stepped top ring to miss the ridge (strangely enough called a ridge dodger ring... ) if your replacement ring set has a step on the top ring then its ok, to be fair without a step will probably be ok as the ridge in the bore should start where the top ring finishes, but its a bit hit and miss.

kev

[physcult]

in the good old days when people rebuilt daily stuff and the country was littered with engine reconditioners they used to fix the problem with a device known as a ridge reamer ( im sure there is a joke in there somewhere... ) but that became redundant when piston ring sets were introduced with a stepped top ring to miss the ridge (strangely enough called a ridge dodger ring... ) if your replacement ring set has a step on the top ring then its ok, to be fair without a step will probably be ok as the ridge in the bore should start where the top ring finishes, but its a bit hit and miss.

kev

You can still buy a ridge reamer on ebay for £60 to £80, but the mechanic said not to bother. In his opinion too much honing, or ridge reamers make things worse - NOT better.

He checked the ridges and said they will be no problem. He has built lots of engines and claims he never had a problem with the top ring. He suggests de-glaze and reassemble (and stay off the internet and away from American go faster salespeople :);)LOL)

[20vT_pop]

I have used a snap-on flex hone for smoothing bores for over 20 years, they smooth out any sharpness in the bore de-glaze to a really nice finish. If as you say there is only a slight lip and not a really hard edged knife edge lip this type of honing would be perfect. I use a 50/50 mix of new clean engine oil and paraffin for the correct amount of lube and abrasion.
As long as you thoroughly clean the bores after you have honed/glaze-busted with really hot water washing up liquid and a scrubbing brush just as you should after machining, you have to clean each bore at a time and immediately dry the bore off as soon as you have finished it before going to the next one as rust will occur virtually instantaneously.

I got my Flex-Hone from Snap-on and have done standard and very high performance engines with it with excellent results.

http://www.brushresearch.com/flex-hone-tool.php illustration of type

Just my opinion tho.
John

[Adam]

Im assuming your using the stock pistons and ring size for this bore and not slightly oversized rings? If so the ridge will be fine as the ring will compress enough to clear it. The ridge is no smaller than the bore was originally and the rings got in ok then.

All I'll say is make sure the ring compressor is perfectly straight on the deck when popping the pistons in. It's good to have someone else pressing down on it while you tap the piston in. If you feel ANY resistance above what you expect stop and start again. Use plenty of lube when sliding the piston in & take your time, don't just hammer it in, (blimey had to check I was on the right forum then!)

[Morris460]

Adam, it's not putting the pistons in that s the problem, it's smashing them on the ridge when running. Hence the use of "ridgedodgers".

[Adam]

Ah I see yes they will go as high as the ridge and may contact it causing damage. Gotcha. Then a set of stones perhaps with an old piston temp in the bore to stop them going down too far sans rings to maybe loose the ridge.

[langysrodshop]

Stones :eek:




Ah I see yes they will go as high as the ridge and may contact it causing damage. Gotcha. Then a set of stones perhaps with an old piston temp in the bore to stop them going down too far sans rings to maybe loose the ridge.

[Morris460]

You would need some "stones" to attempt it:eek:

[physcult]

Im just using the correct size ring for the pistons, and putting them back where they came from.

The engine was taken apart because of the cam and followers. It showed no obvious signs of any other problems. The piston came out of the block easily, and they go back in easily (quite a few times now as well - they have been in and back out again)

[Paul B]

The problem is the top ring, not the piston. The old ring has a radius worn on the edge, that matches the radius on the bore ridge. Stick a nice shiny sharp cornered new ring in, and the first thing it does is shatter against the radius of the ridge when it gets there.

Hence why the ridge dodger rings (if that is indeed what they are called) are normal size rings with a the top edge ground out to clear the ridge in the bore, yet still give a sharp edge to seal.

[langysrodshop]

Yes Paul the are indeed called ridge dodgers, I've used them a few times to keep an old motor going but personally wouldn't use them in any performance engine and certainly not one with a blower.
As you said the sharp edge on a ring will hit the ridge if its not removed. It definitly won't just compress and ride over it.




The problem is the top ring, not the piston. The old ring has a radius worn on the edge, that matches the radius on the bore ridge. Stick a nice shiny sharp cornered new ring in, and the first thing it does is shatter against the radius of the ridge when it gets there.

Hence why the ridge dodger rings (if that is indeed what they are called) are normal size rings with a the top edge ground out to clear the ridge in the bore, yet still give a sharp edge to seal.

[physcult]

In that case, it looks like I should be looking at a way to remove the ridge if possible.

[physcult]

the first thing it does is shatter against the radius of the ridge when it gets there.
.
That exactly what the the man who sold me the rings said.

[Adam]

Stones = the honing stones that fit in a drill and taper out as drill speeds up.. Stick an old piston in the bore so the tool only goes down as far as the ridge and knock it down that way.

[langysrodshop]

You do it with a ridge reamer mate, You would be there a fair while with a honing tool :(
Its false economy these days though with the price of chevy pistons :) The cylinder walls wear along with the rings. The top ring stops short of the top of the cylinder bore so the bore will stay at original specs at the top while it wears larger from there down. This leaves a ridge in the top of the bore, Forcing the piston up past this ridge will cause the piston rings to catch on the ridge, which can damage the ring grooves in the piston. this won't matter if reboring and useing new pistons and rings. If the bores are not to worn it is possible to save the pistons and just change the rings. You need to remove this ridge before you try to remove the piston from the bore.

To use a reamer, you turn the crank to lower the piston to the bottom of the bore. Fit the ridge reamer into the top of the bore, and adjust it to come into contact with the ridge. Oil the reamer and turn the tool with a spanner to remove the ridge gradually, When the ridge is gone you end up with the same bore size all the way up the bore.
The reamer is then removed and you can easily push the piston with rings out the top of the bore with out damaging the ring grooves in the piston.

They look like this

http://www.jcwhitney.com/jcwhitney/product/images/large/G_14236G_CL_1.jpg



Stones = the honing stones that fit in a drill and taper out as drill speeds up.. Stick an old piston in the bore so the tool only goes down as far as the ridge and knock it down that way.

[physcult]

They look like this

http://www.jcwhitney.com/jcwhitney/product/images/large/G_14236G_CL_1.jpg

I just found a real cheap one on US ebay, so even though its very slight, I may as well do it.

[physcult]

I have used a snap-on flex hone for smoothing bores for over 20 years, they smooth out any sharpness in the bore de-glaze to a really nice finish. If as you say there is only a slight lip and not a really hard edged knife edge lip this type of honing would be perfect. I use a 50/50 mix of new clean engine oil and paraffin for the correct amount of lube and abrasion.
As long as you thoroughly clean the bores after you have honed/glaze-busted with really hot water washing up liquid and a scrubbing brush just as you should after machining, you have to clean each bore at a time and immediately dry the bore off as soon as you have finished it before going to the next one as rust will occur virtually instantaneously.

I got my Flex-Hone from Snap-on and have done standard and very high performance engines with it with excellent results.

http://www.brushresearch.com/flex-hone-tool.php illustration of type

Just my opinion tho.
John

How much better are these than just the standard honing tool? I will need to give the cylinder a quick up and down after I ridge cut - is it worth me buying one or just a waste of money for the one time Ill use it? (or the 8 times I will use it - depending on how you look at it:))

[Morris460]

Adam, you cannot do this with a brush hone. It needs to move back and forth otherwise it will just cut grooves. As Steve said, ridge reamer. I've not used one for at least 25 years, never knew anybody still bothered.

[physcult]

Adam, you cannot do this with a brush hone. It needs to move back and forth otherwise it will just cut grooves. As Steve said, ridge reamer. I've not used one for at least 25 years, never knew anybody still bothered.

From what I can gather, they pretty much dont. If I was looking to do the job properly i wouldnt bother. I just want to get the thing running, then start building a new short block bit by bit, and spread the cost out over the months.

[Adam]

Cheers Steve, Never seen one. I've always had Chevy motors & as you say it's so cheap to rebore and fit new pistons I've never had that situation to consider.