gomer

iTrader: (13)

I'm getting ready to install my ARP head studs and I want to get a tap to clean the bolt holes in the block out. I have always used an old bolt to "chase" the holes with in the past, but I want a tap to run thru them this time. If anybody knows the thread pattern on the large and small bolts, please let me know!

Bowtiered

if you don't have a gauge. . . find a nut that fits, then find a tap that fits the nut.

OR used the bolt with a mixture of carb cleaner and nitromethanol... then hit the holes up with some brakleen. that's what we do.

2xLS1

iTrader: (25)

Large - M11x2.0
Small - M8x1.25

gomer

iTrader: (13)

Thanks! That's just the info I was needing.

4thGENRETARD

Just take one of your old bolts, grind the threads flat on opposite sides and voila, HOMEMADE TAP.

GrannySShifting

iTrader: (10)

where do you get a good quality chaser, not a tap

Steve - Race Eng

iTrader: (1)

Do not run a tap, ground bolts, etc. through the bolt holes to chase them. You will remove metal from the block greatly weakening the threads. The block threads are not dirty they are distorted. I run across this problem on used blocks that I am installing sleeves in. I install a torque plate during the installation process. Some blocks are worse than others - the hotter they ran in service the worse they are.
The block threads need to be chased with a thread forming tool which will not remove any aluminum. I purchased one from Time-Sert for about $50. Thread pitch is 11M x 2.0. Part number of the tool is: J-42385-107 phone 800-423-4070

I have used this tool on dozens of blocks and it works great.

Steve Demirjian
Race Engine Development

BergerMan

DO NOT USE A TAP!!! A tap is designed to CUT threads and you do not want to do that. All you want to do is clean them. Using an old head bolt is just fine. Just grind 2 sides flat to create an area for the junk to go. Run it in by hand, remove it, clean the junk off and then run it in again. I then spray brakeclean in the holes and blow them out. When I am done, a clean head bolt can be threaded in by hand.