Champion Head StageII head bolts!!??

[TurboMike]

off center stage II. I've ordered bolts TWICE and still can't seem to get the right ones. Both sets I have are ARP #223-3704. the problem is ALL the bolts are 7/16". On my stage II part of the bolts need to be 1/2". What part number do I need? Two weeks and nothing accomplished.

 

[HighPSI]

You are ordering the correct part. Which bolts need to be 1/2"?

 

[TurboDave]

Originally posted by TurboMike
off center stage II. I've ordered bolts TWICE and still can't seem to get the right ones. Both sets I have are ARP #223-3704. the problem is ALL the bolts are 7/16". On my stage II part of the bolts need to be 1/2". What part number do I need? Two weeks and nothing accomplished.

Your engine needs two different sized head bolts???

 

[jamesmac]

Is there a posibility there should be Helicoils in the 1/2" holes.
Just a thought.

 

[TurboMike]

The 8 inside bolts are 1/2". The 6 outside bolts are 7/16"

My block is part # 25500016

 

[KendallF]

Sounds like somebody pulled some threads out and drilled and re-tapped for 1/2". Check your heads..I wonder if a 1/2" bolt will even fit or if there is enough room to redrill them for 1/2"? Looks like you have an "opportunity for engineering". Perhaps you can measure the lengths, call ARP, and see if they can identify 1/2" bolts that will match those lengths for you. Now what torque sequence and numbers would be appropriate, I haven't a clue.

 

[TurboMike]

It had M&A's on it. I dont' see any helicoils but i guess it looks like that may be a option. Think they would hold up?

 

[FreddieWilliams]

My machinist told me he likes to drill & tap the heads bolt threads on Ford blocks to 1/2" to increase torque/clamping force.

Maybe someone was trying to use the same theory on your Buick block.

Just a thought.

 

[TurboMike]

Well... I guess someone did tap for the bigger bolts. Now the question is where can i find some bolts to work with the heads. Ideas?

 

[HighPSI]

Will the 1/2" bolt even fit through the head?

 

[TurboMike]

Cal,
Nope.

I guess the only choice I have it to somehow add a helicoil type repair in the holes. anymore ideas?

 

[ijames]

Are you looking for bolts or studs? ARP might be able to make you a set of studs with 1/2" threads on one end that then neck down to pass through the head and take stock stud-sized nuts. Also, check the thread pitch in the 1/2" holes to see if it's correct for a helicoil or a normal 1/2" bolt. If it's for a bolt you might be able to use a solid insert but the wall thickness might be too thin. If you can tell me the thread sizes for the holes and for stock bolts (size and pitch, like 1/2-13) I can see what inserts are available.

 

[TurboMike]

FYI

Here is what i did. I talked with Tom and Champion and we decided to have a local machine shop open the bolt holes in the heads to 1/2" to allow for the use of a 1/2" bolt. I then contacted ARP to send me bolts to my dimensions. I've got the engine together and sitting in the car. Should be fired up next week. I post how it went.

 

[FreddieWilliams]

Mike,

Glad you found a solution to your problem.

Does this mean you had to open up bolt holes in the heads to accept the 1/2" bolts?

Let us know how she runs when you get it running.

 

[TurboMike]

Freddie..yep. I'll post more results as they come