ok, I know I can get the msd bit from summit and such for $160 and I know about kinsler that has several types for rent or to buy for $130...

but is there any place cheaper that has the stepped injector drill bits for boring into fuel rails??

the only other alternative is to get a few size drill bits and reamers and do it that way which I can just see me messing up

 

Look for counterbores with built-in pilots at http://www.mcmaster.com, they have a 7/8" for $102. I use 7/8" buna-n hose cut down for injector seals, and it fits in injector holes perfect.

Also, if you have a VERY stable drill press, look into a 7/8" endmill bit. The bottom of the holes will be convex about 5 degrees, but it should still seal somewhere at the base, and somewhat on the sides. Bits Range around $30 foe the cheap ones.

 

I drilled my fuel rail for NipponDenso injectors with regular drillbits :D If you're gonna drill the head, I'd have it machined for accuracy.

 

Shouldn't a hole that needs to seal 45+ PSI witha rubber O-ring be honed to final size?

 

A 17/32 drill bit and a drill press will work fine. 14mm is the actaul size I believe but the 17/32 is a tad under that. Then just take a dremel with a small polishing pad and polish up the inside.
I just drill a small hole first, then set the depth I need on a drill press for the large bit.
Has worked out good so far.

Later
Randy

 

man, you wouldnt believe how hard it was to find a stupid 17/32 drill bit here in atlanta of all places. finally found one and finished up the rail last night. It's still a tight fit on the o-rings but it gets the job done