[modot66]

i've got my heads off for stage 1 work and am putting in cams + bumping compression to 10.25-1 so right now my top end is off the bike. i have about 21,000 miles on the bike and haven't had issues with oil consumption or anything. buuuut...

i am thinking while i am waiting for my heads (was quoted a 3 week wait) does it make sense to pull jugs, hone, clean pistons, re-ring, and put all new base gaskets in? my thinking is while i'm waiting and this far might not be a bad idea to freshen it up.

of course then i start thinking "well why not go to a 107 then?" i don't have bottom end work done and don't want a super hot bike with loud train noise. i could get 107 juggs/pistons for $650 so there's an additional cost. i'm not entirely convinced a 103 to 107 is worth it.

anyone have any thoughts?

 

[modot66]

getting 1.9 intake valve so should work with stock pistons. going with drago 565 cam

i'm bumping compression either way from 9.6 to 10.25

i figured about an extra $100-150 for new base gaskets/rings, etc as opposed to $650 for 107 pistons, cylinders, rings, etc.

trying to decide if the pros/cons of a 107 are worth the extra cash

 

[modot66]

"You're likely going with a flattop piston, .030 head gasket and maybe a touch off the heads to get to 10.25"

spot on!

 

[modot66]

i was wondering this myself so called frank at dragos and he said to pull the cylinder up and if the gaskets look good then no reason to switch. i don't want to have to break in new rings or risk getting debris in the cylinder and damaging the cylinder wall so if they look ok i will just put heads on and run em.

So I have been advised by my indy mechanic if you pull off the heads you should replace the o rings on the cylinder base. it sure would suck to get an oil leak after doing all that work.

 

[modot66]

yep. i was a little worried cause the front cylinder moved a little when i pulled the head, but i don't think it was enough to cause any damage. it just rocked back and forth about an 1/8". the rear cylinder stayed down tight.

later today i'm gonna cut some 1/2" pvc pipe and tighten the cylinders down a bit until my heads come in.

I wouldn't pull them up at all. Doing so may break a seal and cause a leak. If the bases of the cylinders are not leaking then do not disturb them. Bolt he heads on and run the piss out of it.