Yes , Better idea than mine, I have never pulled that bearing in that way.
Cheers Bill.
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E: Engine Damaged quill
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Yes , Better idea than mine, I have never pulled that bearing in that way.
Cheers Bill.
So is Coventry better than VOC spares? It seems they cost a bit less, but I want the best parts.I'm pretty sure Coventry will still supply all three parts fitted. When you consider getting it all machined and fitted locally, plus the chance of your machine shop erring in some way, Coventry usually is the cheapest route. The biggest problem I see is Canadian Customs.
I think they are both excellent. Coventry gets many parts from the VOC Spares Co. If you can get a matched muff/cylinder/piston from the VOC Spares Company, it would certainly end your potential customs' problems.
I have found that shipments from the U.K. can get tied up for weeks in customs. Sometimes they skip customs all together and show up at the door without being charged the taxes. Sometimes they go to a third party and are held for ransom. Sometimes you just pay the taxes when delivered to the door. It's all pretty random and the value of the order isn't always the deciding factor.
I purchased the unbored ET21AS muff/liners and pistons from VOC Spares and had them bored out locallly. They charged a little extra because they had to make a couple of passes. Since then, (even though the local shop does decent work) I have drummed up the courage to bore cylinders myself and finish them with a rigid hone.
Both Coventry and VOC Spares are great to deal with.
I purchased the unbored ET21AS muff/liners and pistons from VOC Spares and had them bored out locallly. They charged a little extra because they had to make a couple of passes. Since then, (even though the local shop does decent work) I have drummed up the courage to bore cylinders myself and finish them with a rigid hone.
Both Coventry and VOC Spares are great to deal with.
Yes.... although given the studs pass through the cylinders into the case, I'm not all that convinced they are really necessary. If there were studs or head bolts threaded into the muff, then that would be a different story. If I had time on my hands, I'd bore a cylinder with/without the torque plate to see how much if any difference it makes. Unfortunately I can't bore them on my small mill, so have to use the lathe and it takes a bunch of farting around to get it right. My guess would be that the difference is minimal. Then when you take into consideration liner/muff fit and liner crankcase fit......
In the stalled "Comet Mongrel " thread, post 129 and 130, there are photos of the torque plate. I suppose one could debate how well it replicates the forces of a properly torqued head. It does have the countersink for the liner on the backside.
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Update, a new cylinder and piston from VOC spares installed, comet seems to run nicely, but it does run hot. For comparison I took the comet for about a 10 km run through residential streets and a main street with traffic lights etc., speed around 30 mph, occasionally hitting 40, accompanied by a 1977 Yamaha 500 XT side by each, doing the same route and speed, so two 500 single cylinder MCs with similar performance. The Comet runs about 130% hotter than the Yamaha, eg, 240 F vs Comet 311 head temps on the exhaust side. I used a thermal image camera to measure temperature, see the pics, the color scale on the right side relates to temperature based on IR emmissions.
An exhaustive 2 minute google search suggests that the Comet temps are within the range for air cooled engines, but what worries me is that it is significantly higher than a similar engine under identical operating conditions. I don't want another seizure, will that mean the Comet should only be rarely used for short trips? That would be a pity.
An exhaustive 2 minute google search suggests that the Comet temps are within the range for air cooled engines, but what worries me is that it is significantly higher than a similar engine under identical operating conditions. I don't want another seizure, will that mean the Comet should only be rarely used for short trips? That would be a pity.
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Nice use of the technology. Would it be possible to remove the steady plate which goes across the two fork legs and supports the muguard and brake balance arm and try it again?
Just looked in my little book, Our Trev' said, Cylinder head temp' for a Twin, Front 230, Rear 220.
So your looks hot !.
What sort of ignition do you use, At that speed, If you use a standard ATD with a Mag',
32 mph is about 2000 revs, If your ATD springs are a bit strong, or if you timed it 36 degrees, That would make it too retarded, Maybe you are too far retarded, Check the timing, Fully retarded ?. Cheers Bill.
So your looks hot !.
What sort of ignition do you use, At that speed, If you use a standard ATD with a Mag',
32 mph is about 2000 revs, If your ATD springs are a bit strong, or if you timed it 36 degrees, That would make it too retarded, Maybe you are too far retarded, Check the timing, Fully retarded ?. Cheers Bill.
Bill's suggestions should be checked out before you get too worried. I would not personally compare the XT temperatures to the Comet's, the two designs are over a quarter of a century apart so you are not comparing like with like. The Yamaha will likely have a lot more oil moving through the cylinder head to move some heat away.
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