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Started at 07:21pm on the 4th March, 2018 by Ivor
Ivor Subject: Conrod
Hi. Just cleaning up my 2003 ES 500 Bullet ready for rebuild and I noticed some damage to the edge of the conrod. It seems to have a lot of little scratches all the way down it and a couple of small dings to one edge. Could this be a problem? I didn't want to split the cases but I`m thinking I may need to polish these marks out to be safe. Is there a problem with Indian conrods snapping? These marks must have been caused through a clumsy engine build. I am going to the expense of gas flowing the head and fitting the 535cc alloy barrel. Don`t want to do all that then have the engine blow up!
Posted: 07:21pm 4th March, 2018
Holetsek Subject: Conrod
Dear Ivor, You can polish the rod and hang it on the wall.. Get the new quality one immediately! Seppo
Posted: 07:49pm 4th March, 2018
Alan R Subject: Conrod
Hi Guys--------Ivor...I think you already know the answer to this one ??....As an Ex-RN Marine Engineer the phrase that came to my mind was}------"Spoil the ship for a hap'worth o tar?? "...You're going to be generating more power ABOVE the piston, so why not beef-up the con-rod / bottom end BELOW the piston to handle it ??..............Steel Con-rod with roller big end and an uprated high capacity oil pump to flood those rollers...And while you're at it open up the oilways in the rocker feed as well......Remember that unlike some other Brit bikes the Enfield uses ALL of the scavanged oil to feed the rockers....
Posted: 09:01pm 4th March, 2018
Mark M Subject: Conrod
Alan R beat me to it, there's an old saying that the best way to finish off a tired bottom end is to fit a tuned top end.

REgards, Mark
Posted: 09:25pm 4th March, 2018
Alan R Subject: Conrod
Having just recently been "Simonised" on the forum I thought I best give a "Polished" answer from now on !!.... sorry Ivor, let's get back on-thread !!
Posted: 09:36pm 4th March, 2018
Adrian Subject: Conrod
"Is there a problem with Indian conrods snapping?"

Yes, particularly on the 500 classic Bullet engines, not so common on the 350. A sedately ridden 500 with an **undamaged** original rod might get a high mileage, but to continue using a damaged alloy rod or a highly tuned top end on the original alloy con rod can lead to some expensive misery.

It's not just a problem with Indian 500 Bullets, Redditch 500 Bullets could throw an alloy rod too. Come to think of it, even some steel con rods can snap. I have seen pictures of a couple of older RE singles where this has happened, Leon Novello might be persuaded to re-post his!

Posted: 10:43pm 4th March, 2018
Leon Novello Subject: Conrod
rikki1 rikki2 P4260001 P4260002 n_a_CA48_J1_M3 90045
file and image uploader
It is know in performance engineering, that a small scratch can develop into a crack which can eventually cause the part to break. Below are some disasters which have befallen owners over the years. It pays to have magnetic plugs fitted wherever you can, as they catch any ferrous metal floating around the oiling system.
Posted: 11:48pm 4th March, 2018
Adrian Subject: Conrod
Thank you Leon.

As far as I know the Alpha steel rods our hosts sell don't snap, even on race bikes! You should be fine with one of those on a tuned road bike, Ivor.

Posted: 10:19am 5th March, 2018
ric Subject: Conrod
Clumsy is being kind!
Letting the conrod fall against the crankcase mouth is never an ingredient of engine longevity
Posted: 12:42pm 5th March, 2018
Ivor Subject: Conrod
I guess I already knew what the answer would be. I`m not intending to tune the motor too much. I`m having the head gas flowed and valve seats re-cut after a conversation with the guy at the Cylinder Head Shop, just to improve things a bit. The 535 conversion is the same price as a 500 new barrel. My iron barrel needs a rebore so I was persuaded to go the alloy barrel route. My budget wont stretch to a steel conrod so a new alloy one it is. But what do I need to know about the crank pin and big end? Is it an easy job to do? I know the new big end bush will need reaming, which I can probably do, or get done, but does the crank have to balanced after? Alan R.Can you expand on opening up the oil ways to the rockers. That does sound like a good idea.
Posted: 08:13pm 5th March, 2018
Alan R Subject: Conrod
Hi Ivor--------I actually meant open the oilways WITHIN the rocker blocks......It's a known mod and Paul ( He who whispers to Bullets ) Henshaw can give you the drill size required I hope.....I modded my last 500 but that was pre Bus Pass-- or so it seems and I can't remember the size...........Just a thought but if you are retaining the floating bush big end then I'd keep the standard oil pumps ( to give the pressure required by a plain journal bearing ) but give them a good overhaul...
Posted: 09:14pm 5th March, 2018
scotty Subject: Conrod
Replaced a few btm end bushes never had to ream any you and split flywheels with four nuts and bolts cut to fit between wheels with nut screwed down two near pln othersb50mm out pln nut off do your nuts up til they contact wheel then two flats at a time each nut, if you run out of thread back them off and pack with washers once they are nice and tight give pln a tap with hammer they should come apart. Might be an idea on 535 to get wheels balanced to 63% bit diff in weight between pistons, mine were done with crank completly apart.ndrill size for rocker box holes are in sites tech notes might want to up carby size i run 32mm jap mikuni and pod filter.
Posted: 03:11am 6th March, 2018
ChrisD Subject: Conrod
Ivor. I too went the 535 route on my 1996 500. I too agonised about the OEM conrod. I too eventually went the steel conrod+roller bearing route and alloy barrel. When the engineer removed the OEM conrod, he discovered it was 20thou longer than it should be, and although there were no nicks there were a couple of dings that must have predated export from India to here in Cape Town. So it was stretching and would soon have snapped! But I didn’t get the system balanced after installation. That was a DISASTER which cost me a complete rebuild as the vibrations destroyed rotor (and hence stator), drive side crankshaft and bearings. So should you rebalance? YES, and to ~63% as Scotty suggests here (and earlier, too). See my thread about this from mid-last year. Cheers, ChrisD PS: just because you have a better-revving engine, make sure the valve retainers are undamaged. One of mine snapped some 6 months ago, barely 2000kms after the above rebuild and the valve made holes in everything it could touch – and I’m still not back on the road. Perhaps this broken retainer was another result of the out-of-balance flywheels etc.
Posted: 07:08am 6th March, 2018
Bullet Whisperer Subject: Conrod
Hi Ivor, First of all, the alloy conrods will break, if exposed to 'high' revs - 6,000 or so should do it, if you want to find out, but they can cope with increased power at 'normal' Bullet engine speeds, say around 5,000 rpm for instance. I have built and tuned quite a number of Bullet engines to date and irrespective of piston or conrod type, have never run into problems regarding vibration due to crank balance factor when a swap has been made. Truing a crank seems far more important than changing the balance factor very slightly, I use a set balance factor for all my lightened cranks, regardless of piston or conrod type and it has worked ok to date. If you are tuning for more power without increasing the rpms, I would polish the alloy conrod at the very least, or fit one of our host's upgrade British made ones. The plain big end will be fine and only yesterday, I had to hone a new big end eye [which someone else had obtained and fitted to a conrod], in order for the floating bush to fit inside, but usually they are a straight fit on replacement. We broke a forged steel conrod in the 500 racer a few years back and were given a free replacement and the design had been improved slightly compared with the broken one. If you fit the plain big end and high capacity oil pumps, just let the engine warm up properly before revving it too much. I have never drilled any rocker feed oil ways to enlarge them, but have opened out the crankcase oilways a little in just a few engines. Regards, Paul.
Posted: 07:43am 6th March, 2018
Alan R Subject: Conrod
Sorry Paul----perhaps that was what I had in mind ??-----
Posted: 10:25am 6th March, 2018
Ivor Subject: Conrod
Hi and thanks to everyone for the advise. Spoke to Paul Henshaw today and he is going to do the bottom end for me. Splitting and balancing/truing the crank is not something I`ve done before so I`m leaving that to the expert. I will do the rest.
Posted: 07:27pm 6th March, 2018
Alan R Subject: Conrod
A wise decision that I'm sure you won't regret.......Keep us posted when you start your re-build please ??
Posted: 08:35pm 6th March, 2018

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