Engine build prep (2014)

I'm really enjoying this thread, Nigel. Thanks again for sharing your experiences.

Concerning hard anodizing the pistons, have you considered going with the Keronite process instead? I've never used it, but it sounds like an even better surface than hard anodizing, and I know it was very popular at one time for coating 2-stroke piston crowns. The process was developed in the UK, and there is probably someone reasonably close to you that is licensed to do the process. More info at www.keronite.com. I'm thinking about it for my next Commando engine build.

There are so many coating and surface treatment processes available now that it's hard to keep track of them all, much less try them. There is so much marketing hype from some of them, that seeing real world results like yours, and others who post here, is very helpful.

Ken

lcrken said:

I'm really enjoying this thread, Nigel. Thanks again for sharing your experiences.

Concerning hard anodizing the pistons, have you considered going with the Keronite process instead? I've never used it, but it sounds like an even better surface than hard anodizing, and I know it was very popular at one time for coating 2-stroke piston crowns. The process was developed in the UK, and there is probably someone reasonably close to you that is licensed to do the process. More info at http://www.keronite.com. I'm thinking about it for my next Commando engine build.

There are so many coating and surface treatment processes available now that it's hard to keep track of them all, much less try them. There is so much marketing hype from some of them, that seeing real world results like yours, and others who post here, is very helpful.

Ken

Click to expand...

Thanks Ken, I will check Keronite out.

Currently I favour anodising however, primarily for its relatively simple and robust nature of application. Will keep perusing though ...

Re: Engine build prep second round!

Fast Eddie said:

It is only fair to point out again that I have ridden this bike quite hard and its done several track days....Nevertheless, the general wear of the undamaged piston looks very good IMHO:

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Nigel

Below are a few photos of other customers used pistons. You can see that the witness marks are very similar to those on your skirt (above photo). Also note that there is no evidence of rocking or rubbing of your piston crown on the bore - indicating proper clearance.

race piston


street piston


race piston


The piston below was raced for a couple seasons


Street piston


A mate to one of the pistons above was also damaged due to a lean mixture and detonation (not as bad as Nigels). Sometimes one piston suffers and shows abuse while the other skates away clean.


Ultra lightened pistons that have been running on my 750 streeter (170 grams each bare).

Well, I thought I'd keep ya'll up dated as to the current status of my rebuild.

As posted earlier, I removed the head to send to Comnoz for his attention. I took the barrels off for a look at the same time and discovered an unhappy piston.

So, I got a new pair of JS lightweight pistons, the next size up, and had them 'Diamondyze' treated. This allegedly protects the skirts and ring lands from wear, and provides thermal barrier protection to the crown. I have never used it before, so we shall see how it pans out. It looks nice though:





The head came back from Jim looking like a million dollars. To call it 'as good as new' would be an insult! The ports look really nice:



3mm oversize and re angled inlet valves and 1.5mm oversize exhausts:






Pistons assembled, I used total seal rings, I know some folk question their value, but I like them. Jim re ground the cam followers so I lubed the JS1 cam with Red Line assembly paste as an extra precaution:



I used my trusty piston support to drop the barrels on. Its a bit over specified for the job really, its a 20mm thick slab of PTFE I had left over from something else, it works really nicely:



After much asking around, I went with Halfords engine paint on the barrels. The silver is a bit bright for my liking but I'm sure it'll dull some in use. Wellseal on the barrel to case joint as usual. Barrels are properly torqued down, head just loosely dropped on for the photo:



Will hopefully get a couple of hours on it tomorrow if I'm lucky... Time is short these days due to work (mustn't grumble about that though eh!?)...

oooh that does look lovely. I wondered the make of timing chain, it seems a chunky item, one of the Chainmans?

Keith1069 said:

oooh that does look lovely. I wondered the make of timing chain, it seems a chunky item, one of the Chainmans?

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Timing chain came from Jim Comstock, I'm not sure of Jim's source though.

Glad you Like it thus far, fingers crossed it goes as well as it looks !

Probably an IWIS chain would be my guess!

From your Aug 3, 2014 post:

Fast Eddie said:

Then I had to sort out the fact that the floating disc wasn't actually floating, or running true, and pushed the brake pads back into the caliper as the wheel turned (resulting on no brake)!!

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I'm wondering how you resolved the issue with the RGM floating rotor? I have one on my front, which looks to run good, but it's going to be a while before it gets tested.
Thanks, Bill

pantah_good said:

From your Aug 3, 2014 post:

Fast Eddie said:

Then I had to sort out the fact that the floating disc wasn't actually floating, or running true, and pushed the brake pads back into the caliper as the wheel turned (resulting on no brake)!!

Click to expand...

I'm wondering how you resolved the issue with the RGM floating rotor? I have one on my front, which looks to run good, but it's going to be a while before it gets tested.
Thanks, Bill

Click to expand...

Bill, I simply relieved the holes in the carrier, by hand and very gradually, until it would just float. Wasn't such a big issue really.

However, I later criticised it for rattling badly and had assumed that the carrier had worn badly. I was only looking at that this very morning and it is actually not badly worn after all.

The rattle I have from my front end is the pads, it is not the RGM disc or carrier after all!

Fast Eddie said:

Keith1069 said:

oooh that does look lovely. I wondered the make of timing chain, it seems a chunky item, one of the Chainmans?

Click to expand...

Timing chain came from Jim Comstock, I'm not sure of Jim's source though.

Glad you Like it thus far, fingers crossed it goes as well as it looks !

Click to expand...

I got my cam chain and adjuster kit from Jim too, although it has been a while, I'm quite sure he said that they are from andychain (iwis). That head does indeed look grrrrreat Nigel :mrgreen:

Well, I had an hour this morning, I had already prepared everything and basically thought 'I can't put this off any longer'...

So I ventured into the workshop to face the 'push rod boogie' and re-fitted the cylinder head!

I used an elastic band to hold them in situ and, basically, it all went together drama free!

Previously I used an AN composite had gasket, fitted dry and clean. It worked perfectly. Nevertheless, I looked a bit closer at the barrel to head face design this time. There really is not a lot of surface area between the pushrod tunnels and the two forward mounted bolts. The holes for these open to atmosphere third fin up... I wonder how many 'mysterious' head oil leaks are actually caused by oil seeping across from the pushrod tunnels to the bolts and 'wicking' up to freedom?? So, this time I put a bead of Wellseal around the pushrod tunnels and oil return hole, just for added piece of mind.

I also tried a trick that Tony Smith told me, and over torqued the fixings by 5 ft lbs in order to reduce the slackening off during those first heat cycles after first start up.

Final thing I'd like to say about fitting a Norton head: when I first removed the head on this bike (my first Commando) I was horrified at the array of socket, spanners and, worst of all, flimsy box spanners that I needed. I now have the cNw ARP head and barrel fixing kit and it makes it SO MUCH easier and more pleasant to work on, using 12 point sockets and ring spanners that fit in the head resesses easily and on the fixings securely. They are not just bling guys, they are worth there weight in gold. I would highly recommend to all.

I'm going to India for a couple of weeks tomorrow, so progress will be postponed until I return.

Here's the head all nailed down:

Well, I got back home from a couple of weeks working in India (it ain't half hot Mum!) and today I got chance of a few hours in the workshop...

I nailed the head on last time, but still had a lot of stuff to attach, set, tighten etc. everything seemed to go together nicely though. I checked the carbs over quickly and they went on without drama. I have a foam filter on the carbs with short velocity stacks inside them. They gave a little mid and top end boost on the Dyno last year, so I may as well keep them on me thinks.

Top end all nailed and tightened now:





I'm clearly not as good a mechanic as many, because unlike some, I don't think I've ever had a bike start first kick after a rebuild and this time it was no different, it took 3 kicks before it roared back into life.

Here it is basking in the sunshine, note the modified pillion mounts so I can take my two young daughters out for short rides:



Fingers crossed that everything stays together and works as it should, for a while at least!

I need to put some miles on it now to ensure its all properly bedded in before I get it on the Dyno and see what difference the head job has made.

Great stuff there, makes me rather envious since my beast is still in bits.
What filter are you using? I want to do the same thing, velocity stacks but with some form of filter and these look good.

Cheers,
Steve.

Nice building with many good parts.
Now I look forward to dyno results. Will be very interesting to see what magic Jim has make.

SteveBorland said:

Great stuff there, makes me rather envious since my beast is still in bits.
What filter are you using? I want to do the same thing, velocity stacks but with some form of filter and these look good.

Cheers,
Steve.

Click to expand...

I used this one Steve:

http://www.ebay.co.uk/itm/PX-air-filter ... 1036462453

Fast Eddie said:

........ note the modified pillion mounts so I can take my two young daughters out for short rides:

Fingers crossed that everything stays together and works as it should, for a while at least!

I need to put some miles on it now to ensure its all properly bedded in before I get it on the Dyno and see what difference the head job has made.

Click to expand...

Best of luck with your break in/bedding in, should prove to be lots of fun. My 6 year old boy and his sisters are always sitting on my Mk3 making varoom varoom sounds when we're out in the garage, they want to go for rides too. I will have to copy your modified passenger peg mounts, looks great Nigel :mrgreen:

No Dyno results yet boys, need to do a few more miles before that.

I have taken it out a couple of times now though, remember, the spec is exactly as before but with the following spec changes by Lord Comnoz:

3mm oversize and re-angled inlet valves (which in previous posts, Jim swears increase torque throughout the range).
1.5mm oversize exhaust valves (fitted mainly to recover the seat).
Ported inlets and a bit of work on the exhausts.
Slightly tighter radius on the BSA cam followers (to broaden the power band).

I would imagine that at the revs I'm currently doing, the porting work cannot be having much impact. But something is working as the bike is noticeably nicer at these lower revs, which is both pleasant from a riders perspective, and interesting from a builders perspective.

Hopefully the 'over 4k rpm' beast is still there too!

Will keep y'all posted...

@ CJ, copy away matey... My girls gave a very positive 'thumbs up' on the new footrest positions today!!

Fast Eddie said:

..."Slightly tighter radius on the BSA cam followers (to broaden the power band)"...

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Grinding your lifters to a tighter radius will reduce the duration. If I remember correctly the Triumph S (standard) lifters have a 7/8” radius and I’m guessing that’s what you did to them. Triumph R lifters (race) were ground to 1-1/8” - same as the B65 BSA lifters (SRM etc).

The smaller radius will tame the cam in the direction towards stock performance and add more low end. The top end and peak HP will not be the same. This could mess with your dyno comparison. Big valves will compensate.

See the profile below. The JS1 cam (radiused lifters) compared to the famous Axtell #3 (for flat lifters). They are nearly identical.

jseng1 said:

Fast Eddie said:

..."Slightly tighter radius on the BSA cam followers (to broaden the power band)"...

Click to expand...

Grinding your lifters to a tighter radius will reduce the duration. If I remember correctly the Triumph S (standard) lifters have a 7/8” radius and I’m guessing that’s what you did to them. Triumph R lifters (race) were ground to 1-1/8” - same as the B65 BSA lifters (SRM etc).

The smaller radius will tame the cam in the direction towards stock performance and add more low end. The top end and peak HP will not be the same. This could mess with your dyno comparison. Big valves will compensate.

See the profile below. The JS1 cam (radiused lifters) compared to the famous Axtell #3 (for flat lifters). They are nearly identical.

Click to expand...

Hi Jim, Yes you are right with the 7/8 radius on the followers. The objective is to do back to back test of the top end mods, in porting, big valves, etc and, in my book at least, cam followers fall into the 'top end' category.

I am not out to find the highest peak bhp figure at the expense of everything else though. The head has significantly greater flow and velocity figures than prior, the re-radiused cam followers are part of the entire 'package' aimed at giving the best all round 'fast street' usable power.

I am not expecting to see an overall drop in peak power, quite the contrary really.

We shall have to wait and see what the dyno says...

What do you mean when you say the exhaust valves were "fitted mainly to recover the seat"?

You can always try both types of lifters and compare. But if your head is set up for the 7/8" radius lifters then you should check that the big valves haven't grown too close to each other and that there are no "clash clearance problems" with the 1-1/8" lifters. Usually both larger intake and larger exhaust valves need re-angling to avoid valve clash with available high performance cams.