393 update - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

brenx · 10-16-2005, 20:41

Ran into a small issue during the dummy fit. Whomever rebuilt the block when doing the 20thou over build screwed up.

Normally during a 393 build the pistons stick out of the bore 5 thou. One side of mine is stick out 5 thou and the other side sticks out 15 thou.

The blocks being decked to square and the pistons are having 15 thou machined off the crowns. Just as well, I have a piston with a 10cc dish

Least I probably won't have to deck the heads

Camshaft choice has also changed as a smaller one made more torque.

Hopefully I can get it back this week and screw what I need to screw together ready for the engine dyno.

Racer · 10-16-2005, 21:13

Is this Pavtec doing this?

CLEVELAND JUNKY · 10-16-2005, 21:53

Must have decked the block after their lunch break

. Whats the best way to check deck height? Do you need the crank rods & pistons installed?

azza · 10-16-2005, 23:24

Yep
AZZA

Rhett · 10-17-2005, 00:14

Good thing you checked and measured. Good one Brenx!

There's a valuable lesson there for amateurs like me.
I need to get the correct measuring tools.

falcon coupe · 10-17-2005, 01:32

This is one engine that will be right the first time.

ch7472 · 10-17-2005, 01:50

So this is Pavtec's doing is it.Glad they are pros??

xdclevo · 10-17-2005, 06:12

Quote:

Originally Posted by ch7472

So this is Pavtec's doing is it.Glad they are pros??

brenx said that who ever built the previous 20th over motor made a hash of the block, and has been discovered during the dummy assemble, by either Pavtek or brenx. Thats what the dummy assembly is for

Does the machining of the pistons affect balance brenx, or is it all good?

brenx · 10-17-2005, 17:17

Machining the pistons will affect the balance and will need to be corrected accordingly. Hopefully I'll have the engine back here this week or early next. Hopefully no more little issues will be encountered.

I'd kill to know who did the 20thou over build. They are definately stooges. [edit] I know the 20thou over build was done in either TAS or SA

Rhett · 10-17-2005, 19:41

I wonder if a variation of 10 though from bank to bank would have been evident on the previous build? Would it idle rougher or always have a slight vibration?