787 Modifacation Questions

[96ROSSIERGSX]

I am in the process of rebuilding my 787. I bought the ski used and knew it already had mods done. First off I know it has a MSD water injection, Rossier Pipe, Ocean Pro (I think that's the brand) Air filters, some msd box by the MPED, and a aftermarket head.

First question, I was looking at the head today and there was no manufacturer on them. I took the domes out and you can see that somebody hand etched 430 on them. Can anybody tell me what this means?

Second Question, I got new pistons that are .5mm over. Can anybody tell me what kind of displacement I will have now? Or does this small of a change not make a difference.

Thanks

 

[jwick86]

The 43 on the dome is the cc size of it. It dropped from a factory 48cc I believe. The 43cc is safe for premium pump gas.

The bored over isn't not significant enough to change your overall CC's enough to worry. I can't remember the formula to figure it out, but I wouldn't waste any time doing it myself either.

Hope this helps

 

[impalaman]

787 modifications question

Gentlemen,

I too am replacing my pistons with WSM units,but I have none of the mods above mentioned.
He'll be asking the same question so I'll go ahead and do it:When over sizing the cylinder just .50 mm(20 thou),is it nesscesary to cut the rave guilotine curve back 15 thou?
I got a note with that warning in the box of my new WSM's.Just the manufacturer protecting his........

Thanks,Greg.

 

[96ROSSIERGSX]

I sent my jugs and raves to Full Bore and they did the .5mm and clearance the raves. I don't know if it was necessary but I wasn't going to chance it.