Jump to content

Royal Enfield WD/CO engine strip


Recommended Posts

In view of my determination to try and get my rebuilt engine to run smoother and because we're in Tier 4. I've started to pull it out again. Tank and primary side removed this afternoon. 

Ron

DSCF3427.JPG

Link to post
Share on other sites

Have you made a crank jig Ron ? 'Radco' mentions that one can be made of wood with 'V' notches and the crank rotated on its own main bearings. Lets hope that you don't have a crank from mismatched halves or something.

Link to post
Share on other sites
Posted (edited)

Rik yes I've made a crank truing jig, built to Jan's sizes for a RE crank. The trouble with these is that they have separate rollers in cages and not worth taking the outers out of the cases for just this job. I'm quite looking forward to checking it now. Ron

PS I guess the V block with main bearings is ok if you just want to check the flywheels, but I want to run clocks on the shafts too.

Edited by Ron
Link to post
Share on other sites

I did mine between centres on the lathe. It’s amazing how easily the trueness can be knocked out. Even tightening the nuts on the big end can knock it out. I found I had to true it with the nuts firm. Tighten, re-true, tighten, re-true and then check again. My biggest issue at the time of the build was finding the right sized shims for the shafts and a few hours were spent on sand paper, not ideal but it needed to be done. 

Link to post
Share on other sites

Hi Chris, I've got a couple of mates with Myford lathes which will take the CO flywheel radius. So that is an option. It's just a challenge to have a go myself. I've been checking on line and youtube, and I believe that any final truing of the flywheels is done after the nuts are fully tightened by knocking the flywheels with a heavy brass or lead hammer. Then there is the process of getting the wheels parallel with each other by squeezing together in a vice or a wedge to widen them. All a learning curve for me, and if it all goes wrong it will be down to Ainsley the engine guy again.  Ron 

Link to post
Share on other sites

It’s good to have a go, I found an article on the net which was really helpful in not being led down the garden path so to speak. Using 2 DTIs helped prevent misunderstandings of what was going on. I also had a marker pen to mark high and low points to aid in exactly where to place the hammer blows (I used a nylon hammer). I also placed a mallet opposite the blow (on the opposite fly wheel) to counteract the force (Newton and all that).
 

Oh and another good tip I read was to smooth out the bores of the flywheels for the crank pin and put a little oil in there to help seat the pin.

I didn’t use a wedge to open up the wheels as by pushing the wedge in, you’re pushing in the opposite direction. I used two pri bars (aka, hefty bars of steel I had laying around) opposing each other which transferred the pressure to the two centre of the lathe.

Edited by Chris Hall
Link to post
Share on other sites
Posted (edited)

All advice gratefully received Chris. I'm going to clamp my truing jig to my surface plate and use two magnetically held clocks against the main shafts and just see what I've got. I've got quite a large copper knocker!!!  Ron

PS the pry bars is a good tip!

Edited by Ron
Link to post
Share on other sites

The magnetic Dial Test Indicators (clock) are brilliant bits of kit for doing this and will make it much easier to understand what’s going on. If one is high and one is low, the shafts are out of plane. If both are high or low, they are out of alignment and just need prying or squeezing. 
 

Good luck, enjoy the challenge and above all, report back on how close you get it.

Link to post
Share on other sites

Well I played around with this today. The readings I got are that the timing side shaft has just 2 thou run out and the drive side shaft has about 5 thou. I phoned Ainsley who had originally fitted the new big end and balanced the whole thing. He says it's very probably as close as he could get it, and if he can't quite get there he always puts any slight discrepancy on the drive side. But he asked me to drop it back and he'd re-check it for me, and also recheck what balance factor he gave it.  In that respect I'd much rather he gives it his expertise than me experimenting.  The new +40 dome piston I've used is about 2.9 onz heavier that a Std flat top. I gather that anything over 1 1/2onz should require a rebalance.

The outer races and rollers are brand new and the shafts are down by only 1/2 thou. 

I'll be looking more closely at assembling the crankcases when the time comes. A few dummy runs and assessing the end float.  Ron  

DSCF3429.JPG

Link to post
Share on other sites

Did you lift it out and spin it 180’ so the shafts are now the opposite way around?

When I thought I’d got it as close as I could, I would turn it around and see if  the figures remained the same.....sometimes they weren’t......doh.

Link to post
Share on other sites

No I didn't do that Chris. But when I took it over to Ainsley he confirmed my findings with his much more professional equipment and expertise. It was great to get out and spend some time with him (2 miters apart) in his machine shop. We discussed other things of course,  but mainly the different ways and end results of truing crankshafts. For instance, he doesn't agree with the idea of doing them between lathe centers, as that can squeeze the flywheels by a few thou and give a false reading.   

Although I felt that I wanted to have a go myself, I think I could have made things worse. In the end I just want it as right as it can be. I'll report back after Ainsley has done it again and during the rebuild. 

I'll have to figure a way to collect it without getting my collar felt now??  Ron

Link to post
Share on other sites

Yeah between centres isn’t the best as you say. I just put turn in the support centre until it’s just touching. You’ll know if you’ve clamped it as you’ll get a deflection on both dials that you struggle to correct.

80 years ago this would have been classed as essential war work and you an essential worker!

Link to post
Share on other sites

If only I knew Rik! Jan would like to know too. Hitchcocks only suggested it might be 65% and others have suggested 58-60%. I even had an email reply from Edd Abbott today. He doesn't know either. After discussion with Ainsley, we went for 60% and now he wants to know if I want him to alter it. God knows! You can't keep rebuilding an engine to try it. It shouldn't be this difficult on and old clunker! Ron

Link to post
Share on other sites

I've seen suggestions that Norton SV and OHV were balanced to 50% pre-war but with figures approaching 70% for the OHC racers which of course do most of their work at much higher revs. Even frame rigidity has an effect though. What's it at, at the moment ?

 

Link to post
Share on other sites

Hi Rik. Ainsley set it at 60% but is going to have another go at truing it and double check the balance factor. Today I've removed the main bearing outers and my mate is making me one of these assembly mandrels. You have to get the cases really hot to remove/replace the bearings, and I'm wondering how you do this as a whole and what they mean by "Apply pressure to both ends"  I'm thinking that a hammer must be involved?  Ron  

Scan_20210105.jpg

Link to post
Share on other sites

I made one of these tools. You tap the races in manually until you have them in the bores a little. Then assemble the cases with the tool fitted between the halves. Then tapping on either end keeps the 2 outer races aligned perfectly with each other. Unfortunately I made my tool from mild steel and never thought to case harden it. It wasn’t long before I distorted the ends which made it a pain to remove

Link to post
Share on other sites

I've got that to come Chris. Mine will be mild steel also. Did you do it cold? I'm wondering about assembling it all ready and then warm the whole lot in the oven. The problem there is my workshop oven is not big enough 😕 Maybe just some local heat with a gas torch?

I'm also wondering why they've given such a precise overall length of 7 7/8"?    Ron

Link to post
Share on other sites

I picked up the crank from Ainsley who has altered the balance to 57%. I'm waiting for the mandrel anytime soon. In the mean time I've bought four new thrust washers from Hitchcocks, which surprisingly are all identical despite having different part numbers and being called End washer and Thrust washer in the parts book? Obviously Hitchcocks think it doesn't matter?  Ron

Link to post
Share on other sites

That’s the issue I had in a few posts up. The shims were of little use and I ended up re-using some old ones and a few of those needed flat sanding to get them correct. 
 

Typically, to keep the whole piston and Conrod ass’y centred, I had to sand 2 shims/washers down, one for each side. It’s far from ideal but the crank was either nipped tight or to slack just by taking away or adding one shim/washer.

Ideally they would be ground but I don’t have that technology or the funds to have some one do it when I had to use trial fit, adjust.

 

good luck!!

Link to post
Share on other sites
Posted (edited)

Chris there doesn't appear to be shims listed in the parts lists. I guess you have to source suitable shims from elsewhere.  But I cant find any on line. I guess cutting some out from shim stock is an option, but I'm not keen on that idea. Or as you say, surface grinding old thrust washers somehow. I'll get it assembled first in due course and see what I need.  Ron

Edited by Ron
Link to post
Share on other sites

OK I've just ordered a sheet of .005" Stainless shim stock. I can cut the OD with scissors and hopefully stack them up, sandwiched between some plywood and cut the ID with a tank hole cutter?  Ron

Link to post
Share on other sites
Posted (edited)

I’ve got my main bearing outers in dead true now. I had a hot air gun wedged in the top and played a blow lamp on each side in turn, and the mandrel was a smooth fit side to side.

 But there is definitely something wrong when I assemble the crank into the cases. I’ve clocked my main shafts and the timing side has 0.002” run out but the drive side has 0.010”.  Ainsley said it’s as close as he can get it, so didn't try to correct it.  I’ll  get a 2nd opinion. I’m wondering if this out of true main shafts is the problem all a long?  Ron

DSCF3436.JPG

Edited by Ron
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...