Main bolt hole thread chaser

[AkBillyBow]

All,

I had my 440 block machined and I want to chase /clean the main bolt holes out. What size bolts are they , or anyone have a link to the correct sized thread chaser?

Thanks !!

AkBillyBow

 

[Juan Veldez]

I keep trying different dies on the bolt to determine what diameter and thread pattern it is. Then I grab the tap with the same numbers and chase the threads. Hopefully you have a good selection of taps and dies to accomplish this.

 

[moparleo]

The main bolt size is the same for all Mopar V-8's. 3/8 X 16 .
Do not use a thread tap, use a chaser only.
Thread taps cut and can make the hole loose, that is exactly what "chaser" taps are designed for. Just to clean the threads only.

ARP 3/8'' x 16 Thread Cleaning Chaser 911

Buy ARP 3/8'' x 16 Thread Cleaning Chaser 911 at San Diego Engine Parts. Get the lowest prices when you shop at SDEP for 3/8'' x 16 Thread Cleaning Chaser.

sandiegoengineparts.com

3/8-16 THREAD CLEANING CHASER

ARP-911-0003 3/8-16 THREAD CLEANING CHASER.

www.allensfasteners.com

 

[Xcudame]

My preference is to turn the block on the engine stand so the main cap threads are parallel or pointing a little to the ground. Spray copious amounts of brake or carb cleaner into each hole and blow out with an air nozzle. It can be dirty depending on how much gunk is in there, but like Moparleo said, you don't want to cut these threads anymore. Hopefully all the threads are already free of any burrs and if not, the thread chaser would help. I'd only chase any threads that might have a burr. The good thing is the block and caps mate together very tight and you can have a little looseness in the threads, but of all the threads in the block, these are the most critical and need to be a tight fit!! Next would be the head bolts, but the parts they are holding don't spin. "If it ain't broke, don't mess with it" applies here.

 

[AkBillyBow]

Excellent .... thanks for all the help !!!

 

[Mopar Nut]

I bought these awhile back, they helped quite a bit for my engine block rebuild.