Drilling LA Heads for Magnum Intake

[kaharshs]

I’m building a 408 stroker magnum for my Duster. I already have a nice Edelbrock intake for magnum heads, but I’m using a set of LA Speedmaster aluminum heads. Has anyone re-drilled LA heads for a magnum intake? I see quite a few posts on magnum heads re-drilled for LA pattern.

 

[4mulas]

I’m no machinist but am thinking that would be very difficult

 

[kaharshs]

I’m no machinist but am thinking that would be very difficult

I should mention I am a machinist. I just haven’t seen it done.

 

[4mulas]

Then how would you do it? I can’t imagine staring a hole at angle. You’d have to make a jig and then???

Maybe just drill the intake for the LA head. It would be much easier.?

 

[kaharshs]

Then how would you do it? I can’t imagine staring a hole at angle. You’d have to make a jig and then???

Maybe just drill the intake for the LA head. It would be much easier.?

I haven’t decided how I plan to do it yet. I’m not an automotive engine machinist, but I have the skillset from aircraft machining to get it done. I will either make a jig for hand drilling or just put them on the mill. Either way I would likely first use an end mill to make a flat for a center drill. Then drill, tap, and helicoil. The reason I would possibly make a jig is so other people could use it or if other people wanted me to dril their heads.

 

[mopowers]

You may be able to find someone on this site that'll trade you straight across for an LA intake.

 

[Illahe]

I haven’t decided how I plan to do it yet. I’m not an automotive engine machinist, but I have the skillset from aircraft machining to get it done. I will either make a jig for hand drilling or just put them on the mill. Either way I would likely first use an end mill to make a flat for a center drill. Then drill, tap, and helicoil. The reason I would possibly make a jig is so other people could use it or if other people wanted me to dril their heads.

This: "Either way I would likely first use an end mill to make a flat for a center drill."

 

[crackedback]

I haven’t decided how I plan to do it yet. I’m not an automotive engine machinist, but I have the skillset from aircraft machining to get it done. I will either make a jig for hand drilling or just put them on the mill. Either way I would likely first use an end mill to make a flat for a center drill. Then drill, tap, and helicoil. The reason I would possibly make a jig is so other people could use it or if other people wanted me to dril their heads.

That jig idea is great until someone gets it then doesn't return it, steals it. There was one available on this site until the prior situation happened.

We had a deal for doing injector cups on PS diesels. Same deal the kit cost around $300, it got sent around free of charge, some asshole gleeped it.

Only way to do it, rent it out, charge $250 plus as a fee. Fee refundable upon return of the undamaged piece.

 

[ch1ll]

Start the hole with a 2 flute center cutting ball end mill a 1/32-1/16 larger than the tap OD size. I have done this so many times I lost count over 27 years.

 

[RustyRatRod]

Getting the angle right is the tough one. That's why you need a jig.

 

[Illahe]

Getting the angle right is the tough one. That's why you need a jig.

If the manifold attaching bore is perpendicular to the China wall, you could make a set of block that situate the head up on the table of the mill at the correct angle.

It would seem to one could get the angles off the engine block

 

[RustyRatRod]

If the manifold attaching bore is perpendicular to the China wall, you could make a set of block that situate the head up on the table of the mill at the correct angle.

It would seem to one could get the angles off the engine block

Right, but it's not. That would make it easy.