GX200 replacement crankshaft with cheap sintered cam gear, anyone tried?

[busted_blocks]

Has anyone used one of these before? I'm not sure sintered is the correct term. They seem to be magnetic but not as hard as the cut steel gears. They seem to me like they would be great with nylon cam shafts, but who would want those on a good engine, but would wear quickly with high CR engine builds. I've attached pics of some of these gears and a steel gear found on stock GX200 crankshafts.

 

[BrownStainRacing]

I havnt seen that gear yet.

I don't see too many Hondas, they usually on farm equipment or utility uses, around here.

By the time I get em, they got thousands of hrs on em and jus not worth rebuilding. Out of round cylinders and such.

 

[busted_blocks]

Around here they are mostly 168F (GX200 clone) and 170F which is the 70mm version which should be very close to the predator 212, though I have yet to see a predator 212 in person yet. Hondas are common on go karts here, but for water pumps and generators it's a lot of those 168F etc. They are made to a price for sure. The lowest version come with nylon cam shafts. I was on a business trip in Taizhou and saw a whole truck filled with engine blocks for these. Someone sure uses a lot of them.

I ran one of those crank shafts, as I had nothing else, and after 10 minutes hard running it showed obvious damage. I didn't break in the engine, so maybe these are OK if you carefully break them in? I might try again as I have 3 of them sitting here, but not anytime soon if I can find the better crank shafts.

 

[BrownStainRacing]

Around here they are mostly 168F (GX200 clone) and 170F which is the 70mm version which should be very close to the predator 212, though I have yet to see a predator 212 in person yet. Hondas are common on go karts here, but for water pumps and generators it's a lot of those 168F etc. They are made to a price for sure. The lowest version come with nylon cam shafts. I was on a business trip in Taizhou and saw a whole truck filled with engine blocks for these. Someone sure uses a lot of them.

I ran one of those crank shafts, as I had nothing else, and after 10 minutes hard running it showed obvious damage. I didn't break in the engine, so maybe these are OK if you carefully break them in? I might try again as I have 3 of them sitting here, but not anytime soon if I can find the better crank shafts.

I never seen that many blocks on 1 truck before, thats awesome.

A few yrs back the blocks where marked 168f.
Here, that meant 1 cylinder with a 68mm bore. So the only true way to tell if it was a 163cc or 196cc was to measure how far the piston moved from bdc to tdc. 163 is 45mm and the 196 is 54mm.

The 170f blocks was the 208cc with a 70mm bore and a 54mm stroke. I heard there was some older 212 blocks that was marked 170f, but I have never seen 1..... yet.

The predator 212 has a .0008" bigger crank pin then the Hondas, they use a different rod. Theres a couple other difference in the two predator 212 versions.

I like to use the same crank taper and crank pin size as the honda, makes fitting and swapping parts easier.

 

[Denny]

Stintered iron and steel parts are nothing new. The big 3 have been doing it for decades.

 

[busted_blocks]

Stintered iron and steel parts are nothing new. The big 3 have been doing it for decades.

The question though is will that cam gear stand up to use in a race type engine with stiffer springs. Those cranks are very very affordable and it would save a lot of cost if they can stand up.

 

[Denny]

I can’t see why they wouldn’t hold up.

 

[busted_blocks]

Then I guess it's worth a try. If you look at the pic "Sintered 4" above and look carefully at the teeth you can see damage. I think I mentioned this was run WOT without being properly broken in but didn't inspire confidence. I'll try one again once I get my engines running stable.

 

[busted_blocks]

I ran 2 hours break in on this crankshaft with sintered cam gear. Here is what it looks like. I'll try and update again after another 10 hours of hard driving. So far it looks fine.