drilling and tapping 9 stud block for 11 stud
Turbo Mini Forums

hi, what size drill and tap do i need to convert a 9 stud to 11 stud engine block?

i asked this a while ago, have been searching for about half hour but it seems not to be on the site anymore.

many thanks

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=191873

cheers, thanks for that

so its 3/8 unc tap i need? many thanks

but only drill the thermostat side 12mm and tap, when stud is fitted and nut torqed down on the side torque to 30 ft pounds only

the other side is the same depth as the others and same torque 55 ft pounds when torqueing the head down

cheers rob, but bought one this morning. thanks a lot for the offer, but dont like using other peoples tools.

where abouts in bristol are you? just moving back to wales from bristol, lived in horfield.

I'm up in Frenchay when I'm around, but spend most of my time on the M4 these days.

right, gonna drill the block for 11 studs this weekend

ive gathered that i need to drill the block to 5/16" to tap out to 3/8" UNC

just after a bit of advice on drill speed for cast iron? fast? slow?

cheers

joe

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

I would go with a slow drill speed and use some cutting fluid as well maybe.

Thats just me though :/

http://www.jolyonway.com

600rpm is about right!

your average mains drill does about 3000 rpm
a pillar drill is best, if not ......
may be use a battery drill as long as ita a parallel hole


NO! cutting compound required on cast

Edited by BENROSS on 5th Nov, 2008.

Cheers steve, lost my data book amongst all the crap in the workshop

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"