SBC Serpentine Conv - Need to tap head

[nicholastheczar]

I've installed a serpentine system on my SBC. One of the bolts that from the plate on the A/C / idler pulley side that rests against the passenger side head is not tapped. Can I tap the head for a 3/8" bolt without causing any damage to the head or pistons? The hole that needs to be tapped is marked below. All my other bolt holes line up w/ the bolts on my new serp setup.

Nick

 

[zebrabeefj40]

Yes, you can drill and tap that hole. Since the pistons stop below the head gasket they're safe. Measure the depth of the hole in that location on the driver's side head. I would not drill deeper than that. Otherwise should not be a problem IIRC.

Nick

I've installed a serpentine system on my SBC. One of the bolts that from the plate on the A/C / idler pulley side that rests against the passenger side head is not tapped. Can I tap the head for a 3/8" bolt without causing any damage to the head or pistons? The hole that needs to be tapped is marked below. All my other bolt holes line up w/ the bolts on my new serp setup.

Nick

 

[cruiserbrett]

well, that location wont hit pistons. It will however hit cooling passages in the head. So you may need to deal with sealing that up somehow. I dont know if your vintage head has a boss inside the casting to accomodate so its entirely possible to hit coolant.

Also, just curious, did you get the reverse rotation waterpump needed for serpentine setups?

 

[nicholastheczar]

I'll watch for coolant passages when I'm drilling. I'm going to try and drill it shallow just to be safe. I did buy and install a reverse rotation water pump. A "reverse rotation" water pump means it should spin counter clockwise?

well, that location wont hit pistons. It will however hit cooling passages in the head. So you may need to deal with sealing that up somehow. I dont know if your vintage head has a boss inside the casting to accomodate so its entirely possible to hit coolant.

Also, just curious, did you get the reverse rotation waterpump needed for serpentine setups?

 

[67azcruizr]

I've always had this done at the machine shop, however if the top outer bolt is in and the two lower ones are in, the force from the belt will be pulling the system inward which should have little effect on that upper inner mount

I'd be hesitant myself hand drilling into a head unless using a mag drill with a depth limiter

 

[nicholastheczar]

I have 3 other bolts in that side, so like you mentioned it may do ok without. It makes me nervous drilling the head without knowing what lies behind the drillbit. I have the brackets that I pulled from a junk yard, I'll probably put those on and call it good.

I've always had this done at the machine shop, however if the top outer bolt is in and the two lower ones are in, the force from the belt will be pulling the system inward which should have little effect on that upper inner mount

I'd be hesitant myself hand drilling into a head unless using a mag drill with a depth limiter

 

[Shawn Russell]

Did you ever get this done / finished?

Shawn

 

[Elbert]

assume you are running old school SBC heads? I don't recall if you would breach a water jacket on the older heads or not. I think they have a good bit of material right in that area. I sure whould check into that first before drilling. I think some of those engines use a stud right there..but the same difference..you would need a threaded hole to make it work.

 

[nicholastheczar]

Did you ever get this done / finished?

Shawn

assume you are running old school SBC heads? I don't recall if you would breach a water jacket on the older heads or not. I think they have a good bit of material right in that area. I sure whould check into that first before drilling. I think some of those engines use a stud right there..but the same difference..you would need a threaded hole to make it work.

I did not do it. I read after posting this and found that most folks that did drill hit the coolant chamber. I'd rather run with out the 1 bolt than worry about breaching my heads and not being able to get the leak to stop.

Nick