2003 Royal Enfield 500 Deluxe

RC4MAN said:
Looks very like a Hepolite
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Nope, I believe it's the standard Indian piston (Velveeta is ringing a faint bell at the back of me mind) fitted to Bullets, here's a borrowed picture comparing with Hitchcocks forged replacement.

Forged vs OEM.JPG


There's some signs of blowing past the rings, but only mild, and no visible scoring on the skirt. However, the OEM piston has that unfortunate reputation for unplanned dismantling. Depending on what else I find, it's very likely I'll splash for a forged one.

A preliminary feel of the conrod did not reveal any up-down play but it can move side-side a little bit. Not quite sure how well the big end can be checked this way? Maybe I should use the rod to turn the crank and see if it feels smooth?

If the bottom end is good, there's probs not much reason to go any further?

Will also have a good look at the condition of the rockers - nobody will be surprised that there are upgrades available, for example, Samrat do rockers with alloy blocks instead of the steel OEM. But if the originals are looking good, no point replacing them.

And the valves need a look. Might do what I've seen on this forum, fill the combustion chamber - water, petrol? - and see if there's any leakage.

Don't have a micrometer to check the bore but can take a good look and feel for wear ridge. Is it worth shoving a feeler gauge down the side of the piston to assess wear on the bore?

What else can I check at this stage?
 
Raymond said:
Maybe I should use the rod to turn the crank and see if it feels smooth?
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Yes.

Raymond said:
If the bottom end is good, there's probs not much reason to go any further?
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I wouldn't, Raymond. If it all "feels" good, I'd call it good. That's about all the Indians did... and the Brits before them. ;)
 
Raymond said:
Nope, I believe it's the standard Indian piston (Velveeta is ringing a faint bell at the back of me mind) fitted to Bullets, here's a borrowed picture comparing with Hitchcocks forged replacement.

View attachment 255644




A preliminary feel of the conrod did not reveal any up-down play but it can move side-side a little bit. Not quite sure how well the big end can be checked this way?
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As long as there's no up and down movement you should be good. A bit of side to side is normal for any motor I've seen. You can use the old piston skirt and a feeler gauge to check bore size accurately enough. There won't be any wear at the bottom of the bore. You can probably still see the hone marks in it.
 
Mailman said:
A quickie hone of the cylinder is required for a new piston and rings, correct?
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I'd agree with that and I have a cheap honing tool that fits in a hand drill - used it on the XS in fact. But the unknown at this point is the state of the barrel - if it's too worn, then looking at oversize on the piston and rings so I'd probably go to Border Engines in Berwick with barrel and new piston for a rebore and hone.

Maybe should look for a tool to measure the bore? At first, I'll go with @Kojack's suggestion, piston and feeler gauges.

Again, there is an upgrade path - a nice British-made alloy barrel block. https://accessories.hitchcocksmotorcycles.com/accessory-shop/500cc-Alloy-Cylinder-Barrel/18458

But I can't justify that for what is at the end of the day an old plodder.

And, if the big end feels good and there's no feeling of roughness, I certainly can't justify this little beaut https://accessories.hitchcocksmotorcycles.com/accessory-shop/Crankshaft-350cc-and-500cc-UK-Made/3280

Yet.

I don't have the luxury of unlimited funds so the options will be weighed and considered. Come to that, I don't have the luxury of access to workshop facilities. Or the skill and experience to use them. But I do have the luxury of plenty of time.

And I'm finding working on bikes more fun than I used to. The advice and help from the people on this forum is a large part of that.
 
Raymond said:
Maybe should look for a tool to measure the bore? At first, I'll go with @Kojack's suggestion, piston and feeler gauges.
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The feeler gauge method, as you probably already know, relies on a known dimension to start with. IE... with a known bore, we can find the skirt clearance, and simple math will deduce the piston diameter... and vise versa with a known piston diameter.
Your piston and bore are both worn. So both your knowns... are unknown, to butcher a famous phrase on warfare. ;)

You'll need a "T" gauge and caliper at minimum to find your bore size. That or a mechanic friend who has them.


 
Thank you for that, Jim. I had a look at the barrel this afternoon.

A few gratuitous garage pics:

PICT0880.JPGPICT0882.JPGPICT0891.JPG


Con rod at tdc - the crankcase mouth is so high, conrod barely out. Head, barrel, copper gasket, the rockers and their blocks. Last, not a great picture but shows carbon build up on top of the spigot and about 7mm down the bore.

Several things from looking at the barrel. First, its in pretty good shape, no scoring or visible damage. As @Kojack said, minimal wear in the lowest portion and honing marks clear but you can see the honing marks all the way down - well I could but as said not a great picture. Yes, the marks are almost polished away mid stroke front and back.

Then used feeler gauges to see what I could measure. With piston skirt inserted at lower end of barrel, could just get a 4 thou feeler gauge in there. Tried the top ring in various places and - didn't tell me a lot. With the ring near the bottom of the barrel, end gap was 12 thou, at halfway up about 15. So the barrel is worn but I'm not much clearer how much or if that's bad. Obviously, the ring will be worn.

I don't really trust meself with measuring things. Could buy some of those telescoping gauges and a micrometer. Or could go to an engineer and ask them to measure it.

Hmmm.
 
Jim, You're absolutely correct. However, Raymond's bike is low mileage. If he gets a feeler measurement within factory specs at the bottom of the bore, I'd say there's no wear at that point and check the top of the bore the same way. What would I do? Well, I have the tools to do a precision measurement so it would be easy for me. I'd also just have it bored .010 over to make it petfect, since I'm buying a new piston and rings anyway. I'm not a machinist anymore and I have no idea what a bore job costs now but probably not that much, compared to parts cost.
 
Thank you for the suggestion, @Kojack.

All considered, a rebore and oversize might be the best way. Takes some of the guesswork out of the equation. Don't know how much a good rebore and hone costs, maybe £60-80? Hitchcocks list their forged piston in standard and +20 only. But with a new piston & rings and properly run in, no reason to believe that's not going to outlast my use of the bike.

Oh yes, the leftfield option - H's also list an oversize piston, 87 instead of 84mm. Also standard and +20. Gives you 535cc, as used in the café racer. For when you need the raw power.
 
Raymond said:
Thank you for the suggestion, @Kojack.

All considered, a rebore and oversize might be the best way. Takes some of the guesswork out of the equation. Don't know how much a good rebore and hone costs, maybe £60-80? Hitchcocks list their forged piston in standard and +20 only. But with a new piston & rings and properly run in, no reason to believe that's not going to outlast my use of the bike.

Oh yes, the leftfield option - H's also list an oversize piston, 87 instead of 84mm. Also standard and +20. Gives you 535cc, as used in the café racer. For when you need the raw power.
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Nothing like a fresh bore and piston. The last time I paid for a bore job was back in the 70s, and it was $8 per hole at the time on an auto engine. I wouldn't think a shop would charge more than one hour labor.
 
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