Jug spacer thoughts?

['00 WO-YA!]

I've been thinking a lil bit about the transfers being partially covered @ bdc. Obviously a shim to raise the jug would solve this & change port time a bit too. Who can the shim be bought from? I would also want to have the top of the jug milled to compensate for compression loss by raising the jug. I guess the full amount can be milled off but if it can't I can have as much taken off as possible & then order a custom thinner head gasket to make up the rest. Thoughts & suggestions welcome.

 

[blasterdemon7]

It would be better to just get the jug ported. I really don't think that would work out like porting.

 

[sicivicdude]

I've been thinking a lil bit about the transfers being partially covered @ bdc. Obviously a shim to raise the jug would solve this & change port time a bit too. Who can the shim be bought from? I would also want to have the top of the jug milled to compensate for compression loss by raising the jug. I guess the full amount can be milled off but if it can't I can have as much taken off as possible & then order a custom thinner head gasket to make up the rest. Thoughts & suggestions welcome.

Cometic will make custom thickness spacers if you like but there are other options......

The best option is to get a 3mm stroker crankshaft. If you use the spacer plate, it ends up the exact same way with the piston moved up and the jug moved up to match BUT if you are going to redesign the head anyway, you can port for the stroker without the spacer plate and the piston will then drop down below the current transfer port height.

It would be better to just get the jug ported. I really don't think that would work out like porting.

This would be in addition to porting. The piston doesn't drop down far enough to completely uncover the transfers and exhaust port. No amount of porting will change that fact.

 

['00 WO-YA!]

Cometic will make custom thickness spacers if you like but there are other options......

The best option is to get a 3mm stroker crankshaft. If you use the spacer plate, it ends up the exact same way with the piston moved up and the jug moved up to match BUT if you are going to redesign the head anyway, you can port for the stroker without the spacer plate and the piston will then drop down below the current transfer port height.



This would be in addition to porting. The piston doesn't drop down far enough to completely uncover the transfers and exhaust port. No amount of porting will change that fact.

Right, just trying to correct the transfer coverage. The 3mm stroker is in the plans & I definitely would like to do that. Just for the short term I'd like to try the spacer, if nothing else for the science of it, I'm experimental that way, lol!
Also, roughly what should the spacer thickness be? I read the MacDizzy build & he used 1mm, would that be sufficient?

 

[blasterdemon7]

I was. corrected on something I was not aware of.I:I

 

[Larry's Shee]

problem is if you take material off top of jug then you might be jacked if you want to go to 3mil later

 

['00 WO-YA!]

problem is if you take material off top of jug then you might be jacked if you want to go to 3mil later

Hmm, good thought. What about having the combustion chamber shaped to compensate after going to the 3mm? We could also go to a thicker spacer later. I'm not concerned about the stock/nonstop appearance, I know some people are, I'm more about function, Haha, a lil black paint hides alot.

 

[sicivicdude]

problem is if you take material off top of jug then you might be jacked if you want to go to 3mil later

Spacing the jug and removing material from the top means that you cannot go stroker without the spacer plate. With the vito's stroker plate, it's still OK. The head would have to be rechambered differently obviously because of the jug position but it's still doable.