BBM oil restriction hole size

[Dryhoze1]

Hi guys,
Does anybody know off the top of their head the size of the hole (BBM head) to drop a oil restriction aluminum rod in. (Below rocker stand)
I will drill a .069 hole in rod.
I'd measure but don't have heads in front of me
Thank you
Brian

I'm guessing 1/4" but not positive

[Yellow Truck]

Probably would be best to ask BBM, but on mine I noticed they were not the same size. On one head the restrictor dropped all the way down the passage, on the other side it sat on top.

I may have my rocker stands off tomorrow to stop them and I'll try and get a dimension.

[fryedaddy]

you may have to trim the rocker bolt inserts.my bbm heads the inserts are not screwed down far enough to put anything in the oil hole

[Yellow Truck]

Been a while since I had the stands off, don't remember an interference problem on the side where it stayed up, the other side it fell in completely.

[Dryhoze1]

you may have to trim the rocker bolt inserts.my bbm heads the inserts are not screwed down far enough to put anything in the oil hole

I did do that prior to installing thanks to Brent's recommendation.

I called BBM but gone for the holiday weekend & I planned on knocking this out this weekend.

Thanks to all who replied!
Still hoping someone knows this diameter
Have a great weekend everyone!

[Yellow Truck]

Tell you what, who ever gets the answer first, posts. I'm in Mountain time, so if you are east coast you have a head start!

[blykins]

~1/4".  A 5/16"-18 or 1/16-27 NPT tap will pick it up and offer good thread engagement.

[Yellow Truck]

Brent,

I've seen a few folks on here talk about tapping the hole and threading in a screw. I am a rookie, possibly in over my head, but part of why I'm doing it is because you only learn by trying, so let me embarrass  myself.

Do you take the heads off to tap the holes? I have a tap and die set but I've only used it to tap old and dirty holes. I'm worried that cuttings will contaminate the engine.

[blykins]

It needs to be done with the heads off. You will get all kinds of shavings down in places where you don't want them to be.

[Dryhoze1]

Thank you for the reply guys !


Paul,
What I've done in the past was
Get a round aluminum rod
In this case it will be 1/4"
Cut 2 pieces about 3/4" to 1" in length
I then get a piece of wood & drill a 1/4" hole in the wood
I then drop the piece of aluminum I just cut into the drilled hole of wood
I then drill a .069 hole in the aluminum rod
The wood holds the rod for you
I do leave a little bit of the rod out of the wood hole for easy removal after hole is drilled
I then finish cut the aluminum rod to desired length and drop into head.
No need to tap or remove head. If heads were off then obviously tap method would be preferred

On a side note
If 1/4" rod is to snug to drop in head, I put it in a drill chuck and spin it with some wet sandpaper between my fingers. You can get the desired fit easily.

Good luck
Brian

[Yellow Truck]

Brent - heads off is what I thought, so I won't be doing that. As I understand it - that means a new set of head bolts, but even if it didn't, it would mean all the other stuff I don't want to do.

Brian - I assume the process you describe is to drill a 0.069 hole down the middle of the rod. I have 0.060 restrictors down there now. I think I just need to stop them off.

Since I can't find the T&D instructions for the FE street version (it has been a while since I saw them last) and T&D haven't posted them (only the race version) I don't think I'll yank off the rockers today.

[fryedaddy]

It needs to be done with the heads off. You will get all kinds of shavings down in places where you don't want them to be.

could you do this with the heads on if you use grease on the tap to catch the shavings.i have seen it done in other situations

[Drew Pojedinec]

I don't think anyone could answer that but you Frydaddy..... if they are your heads, do what you think is best.

(I've also heard shaving cream, tap the hole, than shop vac it out, of course I'm paranoid and would pull the heads).

[Barry_R]

You do not need to tap the hole.  Just throw something in there.  Don't matter what it is - a chunk of aluminum, steel, brass, wood, silly putty, whatever.  If its not a 100% seal it will still be plenty enough to restrict oiling to a non-critical amount.  I never do it - but you certainly can do so if you wish.  The thing you slip in there will not go anywhere - can't get by the head bolt down low and can't get past the rocker bolt up high.

If you are convinced that you have too much oil you can also purchase restrictor pushrods with a smaller diameter hole in them - like maybe .015 in diameter.

[fryedaddy]

I don't think anyone could answer that but you Frydaddy..... if they are your heads, do what you think is best.

(I've also heard shaving cream, tap the hole, than shop vac it out, of course I'm paranoid and would pull the heads).

i just asked if it would work,i dont guess i would chance it with my new engine,it was just another one of my brain farts