Valves hitting piston after rebuild

You will also loose compression ratio with stacking gaskets by increasing cylinder volume. AKA loosing your squish factor. I'm telling you if its barely bumping , find out where its bumping per the instructions above and just relieve the piston (grind or sand a pinch from it till it quits hitting). The Millwright trade (precission machanics) use this method. They actually have a blue washable type ink they use for this. But you can use any coloring that will do the job. Its gotta be kind of thick so it won't run everywhere. It just colors where its making contact. I swear Best, Cheapest and most likely quickest way to solve your problem . Unless its hitting in a ring fashion like that photo above. Then you will have to use one of the other methods of getting around this problem of yours.

But since the piston is now higher than it was it shouldn't matter right?

That's my thinking if the stock 150 con rod is shorter (now it sits on a longer rod) and your spacing things out it should reset back to the stock compression, my only concern is that evertime you space the engine your technically knocking timing out, I will do it in stages like 2.6mm them 3mm until they start to clear. I would like a higher compression but my concern becomes the stock Rod that's been bored out to accommodate the wrist pin.

Shouln't matter if it is hitting something inside ?

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Originally Posted by 4950cycle

Shouln't matter if it is hitting something inside ?

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Well if the valves are hitting the piston they will either bend or brake causing a loss in compression and a broken engine.

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Originally Posted by arancara

That's my thinking if the stock 150 con rod is shorter (now it sits on a longer rod) and your spacing things out it should reset back to the stock compression, my only concern is that evertime you space the engine your technically knocking timing out, I will do it in stages like 2.6mm them 3mm until they start to clear. I would like a higher compression but my concern becomes the stock Rod that's been bored out to accommodate the wrist pin.

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I can't see how the timing would be affected as the movement of the piston and valves would be not be changed.

A higher compression is not a good idea on a air cooled engine as it would generate a lot more heat and put extra stress on the conrod.

When you add your thicker base gasket make sure that the clearence between the valves and the piston is not too small as the valves need room to expand when they get hot.

Thanks spencer, it's rocking a oil cooler now as well to aid in less frequent oil changes

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Originally Posted by arancara

Thanks spencer, it's rocking a oil cooler now as well to aid in less frequent oil changes

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Oh sweet you managed to fit one, could you upload some pics some time?

I will do once all done it will be on the blog I also got an upgrade from manufacturers because of the blog I opted for a link pipe and they emailed me saying since you have been doing the blog would you like an upgrade to a full stainless steel manifold we have been working on, that's due to arrive in August no more pressed bends!

A bit late, and inactive, but here's the oil cooler on:

http://xtrsproject.files.wordpress.c...09/dsc-260.jpg