Torque plates

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lcrken said:
I experimented a lot with using sleeved cast iron cylinders for 920 engines back in the '70s and '80s. I found that torque plates made a large difference in performance for them. I've detailed those results here somewhere on the forum, but it's been a few years. In summary, without using the torque plates, you get major blow-by at the top of the bore at the spots where the through bolt counterbores are bored through to fit the sleeves. You will see large black spots in those locations. The engine will also smoke noticeably. It will still feel like it makes a lot more low end and mid-range power, but not so much on the top end. Using torque plates to bore and hone fixes those problems. I also found that I needed to cut grooves for copper o-rings in the top of the liner to keep from getting leakage past the (copper) head gasket.

I never saw the need for them with stock 750 and 850 cylinders. I went through several of them in road race bikes, without using torque plates, and never saw any bore problems. When I built an 850 out to 79.5 mm bore for my grandson's Commando a few years ago, I used the torque plates. Not sure if it was really necessary, but the cylinder does get a bit thin at that bore, and it wasn't that much extra work, so I did it just in case.

I also didn't use them with 750 and 850 alloy cylinders in the race bikes, and had no bore issues. If I were doing a new 920 conversion to an alloy cylinder, I would probably use them, just in case. The only one of those I've done recently was a 81 mm bore Maney cylinder on an ultra-short stroke 750 for landspeed racing, but it didn't have the problem counterbores (bolt heads on top of cylinders instead), so I didn't use them for it either.

Just relating my own experience, for whatever it's worth.

Ken
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Thanks Ken, seems like the easiest test is to wait till I lift the head again and see if there is blow by evidence as you describe before doing too much else on this.
 
Onder said:
I think you had better get up to date on Enfield in India. The make a lot of Interceptors. They sell them all. A modern bike with traditional styling . A bike that runs well and doesn't break. It cannot be long before they punch it out and hot it up a bit. If they don't aftermarket boys will.
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Are there any bikes today that don't run well and are not reliable? I think even Harley is pretty reliable today just like cars are WAY more reliable than they were 50 years ago!

For instance, you really cannot compare a modern Bonneville T100 to a 1970 Bonneville. They make look similar but are very advanced compared to the 1970 model and the one I have for sale will cost you almost $3000 more than going to a dealer and paying full price today.

I think most of us are not in this for real power, real handling, real breaking, and real reliability - we're just old farts not moving on :)
 
Tell you what, an 865 Enfield will take some catching if these boyz are correct, big bore and cam etc boosts power from 40 to 65 rwhp !!

 
Impressive re the RE 650! I was interested in the Interceptor a couple of years ago but I felt it needed at least 20-30 more HP for me to like it. So I bought a Kawasaki Z900RS Cafe. Now that HP can be added with "bolt-on" parts!

"All those CCs aren't going to matter much soon"

Funny, I spent years building engines for high performance/competition. I built quite a few competitive car engines in drag racing (mostly Super Stock class) and now see those cars/ impressive ET/trap speeds being outrun by a car that can stop by the dragstrip on the way home from the grocery store. And the E-car does it without all the noise and (melo)drama required of the ICE car. The ICE vehicle may be 2021's equivalent of the 1910 horse and buggy - still in normal use but not for much longer...
 
I would say that as of right now there are few of us on this list that would not agree that the game is about over for us.
Horse to steam. Steam to diesel. Diesel to electric. Sic transit gloria.
Not interested in electric bikes any more than getting a new modern petrol bike. I shall ride the old stuff until they are either banned or the petrol price and availability forces me to hang up my helmet.
...won't mention old age.
 
I still buy 'new' bikes - last one was in 2019 and of the 6 bikes my wife and I own (3 each), the next oldest to the Norton is a 2014. I'd be happy for my next new Moto to be electric but the range/availability of charging facilities is still insufficient for what we do. I figure we need at least 200 miles of range on the highway or much faster/more numerous charging stations to be workable.
 
A good friend has a 650 Interceptor. He's a decent rider. It doesn't keep up with my single carb, 23T sprocket, heavier mk3 850 :) . We swapped bikes earlier this year. He was impressed with the torque, but too heavy for him. I was impressed with the lightness of the RE. But it felt a bit flimsy, built to a budget. Hell of a bike for the price. I liked it.
 
Onder said:
I would say that as of right now there are few of us on this list that would not agree that the game is about over for us.
Horse to steam. Steam to diesel. Diesel to electric. Sic transit gloria.
Not interested in electric bikes any more than getting a new modern petrol bike. I shall ride the old stuff until they are either banned or the petrol price and availability forces me to hang up my helmet.
...won't mention old age.
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Trust me - I agree. Not even 1975 for me - they shift on the wrong side.

However, if ever buy a new car it will be plug in electric. The decent ones will go much farther than I drive, there's free charging at my grocery store, and plugging in at home costs almost nothing for a full charge. My current Mercedes, a 2011, only has 45k miles and I gave my grandson my 2010 Mini Copper that had 40k miles last year.
 
Mart UK said:
' felt a bit flimsy, built to a budget. '
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Couldn't agree more, was offered one but it felt so insubstantial. Xmas cracker instruments and that baking tray engine cover! My mate's Thaiumph (yes, more expensive) just seemed to cr*p all over it from a great height......

But hey ho.... Some people love 'em :-)
 
Onder said:
You can flog them and they will run with a Commando and you can do it regularly.
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Indeed.
My mate had one, it and my T140 were well matched (although the T140 had more drive out of corners).
But, after a good thrash, we’d park up and I was always pleased to see nothing had broken or fallen off or started to leak on mine … whereas he just took it for granted!
 
I was really enamored with the (Indian) RE Continental GT in it's single cylinder format but I absolutely could not deal with 20-something HP. The first one I saw was when we were at the IOM for the Manx GP some years back; I thought it was about the coolest looking bike around! The current one doesn't match the single for looks but, of course, it has some decent power...about the same as our Commandos.

Speaking of the IOM/Manx GP, we're flying there tomorrow for the week...really cool! Any Moto-heads should go the the IOM at least once. I prefer the Manx GP to the TT; it's slightly less manic!
 
Maybe my problem was I came at it quite literally from my Commando, stepped off one straight on to t'other. Perhaps if I'd approached on something a little less 'agricultural' I might not have perceived the obvious differences as shortcomings....
 
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