TK4
Well-known member
You're disregarding everything that all the good folks here have been telling you.
Looking for a good/fast/cheap way out and there isn't one.
Find a low mileage donor motor and plug it in.
This thread is going nowhere.
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Cylinder Honing Where?
- Thread starter Jaymod
- Start date
Looking for a good/fast/cheap way out and there isn't one.
Find a low mileage donor motor and plug it in.
This thread is going nowhere.
I’m not disregarding anything, they are valid points, but I I’m going to put this engine back together. If it works great, if not I throw it in the corner til I can do right.
I’m most interested in the technical why’s to someone’s opinion, just saying no, you’re wrong, you’re an idiot, it can’t be done are not all that helpful, if it’s followed up with a specific measurable why, or personal experience.. that is useable information
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I’m most interested in the technical why’s to someone’s opinion, just saying no, you’re wrong, you’re an idiot, it can’t be done are not all that helpful, if it’s followed up with a specific measurable why, or personal experience.. that is useable information
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boyoboy
Well-known member
how far out of spec is 16 thou ?
oversize rings are meant to fit oversize pistons.
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Sometimes we learn by our mistakes.
Keep records of everything you do and maybe you can benefit from it all.
Apparently service limit is .027” , but I haven’t honed the bore yet.
I hear you about the oversized rings, but there meant for a bore that is 0.5mm bigger then the standard 74mm and my bore is no longer 74mm lol
I have the cylinders being measured by a computer controlled machine, should have accurate measurements soon.
Many people have reported great results by going this way, would they have got the same result with the standard ring? I have no idea, I can’t find that data.. just that the oversized rings work minus the oil ring expander, you have to reuse the original.
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boyoboy
Well-known member
well this was an inte4resting stumble.. its the fog man who spoke of what you want to try with the motor. that old guy has been giving good advice on the ex500 ninja500R fror decades. but he is especially well k own for the fog mod to airbox along w jetting for improved drive-abilty and power. kind of a famous 500 guru. Im cheering for the underdog lol. best luck.
boyoboy
Well-known member
on the other hand, maybe the problem will be rectified at the head/barrels junction with the lapping you did.
waiting to see how round the bores are..
this from madmike (post55)- good stuff I think.
" just button her up as is. Use lots of copper spray on your head gaskets and add 10lbs extra head bolt torque."
waiting to see how round the bores are..
this from madmike (post55)- good stuff I think.
" just button her up as is. Use lots of copper spray on your head gaskets and add 10lbs extra head bolt torque."
Yeah... don't do this.
Adding 10# of torque to the head bolts will just stretch them, not make them any tighter. You want more clamping? REPLACE the 35year old headbolts.
Clean the headgasket and apply the thinnest coat of your favourite spray paint possible. More is not better when you're trying to seal a gasket surface. More just squishes out.
Clean the headgasket and apply the thinnest coat of your favourite spray paint possible. More is not better when you're trying to seal a gasket surface. More just squishes out.
Mad Mike
Well-known member
I'd have to get my hook's law calculator to prove elongation and clamping forces -- I can 100% assure you are incorrect about clamping force being constant as torque increases. I'll agree there will be a minuscule amount of stretch, but 10.0 M6 head stud will convert an extra 10ftlbs of torque almost entirely to clamping force.
When I have a janky motor that's on it's last assembly, I use copper spray to help seal and fill irregularities from cyl to head, then overload the head bolt torque to takeup any slop in the mating surfaces.
Not race or rocket science, just a cheap and dirty way to give a junk motor a few extra breaths.
On board with using copper spray (done it successfully), not "any spray paint" (tried that once...did not seal), and if you want to overtorque head bolts, I'd rather do it by angle, not torque. Take note of the angle that it takes to do the last 10 N.m of torque to reach specifications, and give it a round of that much angle again. This only applies if specs don't already call for torque + angle. If they do (and especially if the bolts are "always replace"), they are already stretch bolts, not to be overtorqued.
Science lesson:
Steel is almost elastic. Elastic means when it is stretched then released it returns to it's original shape. Steel will stretch, but doesn't return to it's original shape, it will be microscopically longer.
On every power stroke, every time the engine fires, it stretches the head bolts, over time the head bolts get noticeably longer... which is why you re-torque your heads. (YEAH, I know YOU don't re-torque your head bolts, but you're supposed to).
Every time the head bolts stretch, they lose a little elasticity and get harder (work hardening). When they lose elasticity, you lose clamping force.
So, long story short: head bolts wear out, and it doesn't fix them by over torquing. Over torquing them will over stretch them, necking them down, making them weaker, making a bad situation worse.
The FIX is to replace them. The EX was a CHEAP bike, built to a price point, and those head bolts are just this side of mild steel, as in "not very good from the get go".
I just did a GS1000 motor and three of the 12 head bolts were 0.100" longer than stock. They are a stupid design where they neck down to 8mm in diameter to facilitate oil flow up to the head. They got replaced with 10mm tool steel head bolts I made ... so the clamping forces hold the head down, not stretch the bolts.
I am under the impression torque + angle head bolts are stretch to yield, where the bolt "stretch" is what gives you clamping force... and the bolts are one use only. I haven't seen a bike with stretch to yield bolts, and I know for certain a EX doesn't have 'em.
Torque is a lousy way of measuring clamping forces... cuz you're not measuring clamping forces, you're measuring the "gall" in the nut to bolt and the nut to head surface connections. A much more precise method is to measure how much the bolt stretches.
Steel is almost elastic. Elastic means when it is stretched then released it returns to it's original shape. Steel will stretch, but doesn't return to it's original shape, it will be microscopically longer.
On every power stroke, every time the engine fires, it stretches the head bolts, over time the head bolts get noticeably longer... which is why you re-torque your heads. (YEAH, I know YOU don't re-torque your head bolts, but you're supposed to).
Every time the head bolts stretch, they lose a little elasticity and get harder (work hardening). When they lose elasticity, you lose clamping force.
So, long story short: head bolts wear out, and it doesn't fix them by over torquing. Over torquing them will over stretch them, necking them down, making them weaker, making a bad situation worse.
The FIX is to replace them. The EX was a CHEAP bike, built to a price point, and those head bolts are just this side of mild steel, as in "not very good from the get go".
I just did a GS1000 motor and three of the 12 head bolts were 0.100" longer than stock. They are a stupid design where they neck down to 8mm in diameter to facilitate oil flow up to the head. They got replaced with 10mm tool steel head bolts I made ... so the clamping forces hold the head down, not stretch the bolts.
I am under the impression torque + angle head bolts are stretch to yield, where the bolt "stretch" is what gives you clamping force... and the bolts are one use only. I haven't seen a bike with stretch to yield bolts, and I know for certain a EX doesn't have 'em.
Torque is a lousy way of measuring clamping forces... cuz you're not measuring clamping forces, you're measuring the "gall" in the nut to bolt and the nut to head surface connections. A much more precise method is to measure how much the bolt stretches.
Well, still waiting for my print out. He swears I will have it tomorrow.
The instructions that I’m following suggest that the head is clamped down in three stages ending at 40ft-lbs which is 11ft-lbs higher then original spec.
With the head and barrels lapped it should have the best chance of sealing, head gasket is completely clean waiting for a coat of paint.
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The instructions that I’m following suggest that the head is clamped down in three stages ending at 40ft-lbs which is 11ft-lbs higher then original spec.
With the head and barrels lapped it should have the best chance of sealing, head gasket is completely clean waiting for a coat of paint.
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What do the instructions you're following say? Normally you do dry but you are already going 30% over torque, if you lube, that will be another 30% or so on clamping force and I expect things will start to break.
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