Tim Burgess

I just purchased a Holley Stealth Ram and discovered that my Bosch fuel injectors, purchased from TPIS in '99, are 0.070" too tall to fit between the rail and base. The fuel rails on the HSR are secured by screws laterally rather than vertically, as they are in the stock TPI cfg. Thus if an inj is too tall, the clearance mounting holes on the rail will not line up with their corresponding tapped holes in the base.

I tried Accel, Mopar, stock Rochester, and a second set of Bosch inj and found that the Accel and Mopar inj fit, while the Bosch & Rochester inj are both too tall. Upon measuring the inj, I found that the Accel and Mopar inj are 0.100" shorter from the fuel inlet to the shoulder where the inj body necks down in diameter near the pintle.

The best fix appears to be milling 0.080" from the base where the injectors mount to increase the base to rail clearance.

I contacted Holley, and they claim I m the first person to have this problem, however, I find this difficult to believe.

Has anyone else seen / heard of this issue?

Free Bird

iTrader: (1)

I've had no problems. Accel.

formula350sd

iTrader: (2)

I have ford motorsport injectoids on mine and they fit good there loud though kind of irratating

IROCZZ3

I had 24# injectors from an LT1, which are Bosch or Rochester I think, and had no problems with the fuel rail bolting up.

Maybe you can elongate the holes slightly in the fuel rail? Or maybe you got a misdrilled set of fuel rails?

Tim Burgess

Unfortunately, there's not enough material between the bolt hole & the rail fuel galley to elongate the hole by 0.070".

Holley sent me a second set of rails, which have the same measurements as the original set I received, and I also had a tech measure the base to rail height on a unit @ Holley & it measured the same as both rail sets when installed on the base that I now have.

Z69

Swap injectors or fill the mount holes on the base with your choice of filler. Then redrill the holes. You could heli coil or use inserts to make them stronger if desired.

Tim Burgess

That's not a bad idea...........I'd have to find some quality metal filled epoxy - I don't know how well JB Weld machines......

406TPI

iTrader: (1)

If the misalignment isn't too bad, you could simpley insert helicoils. However, if a helicoil won't cover it, buy yourself some aluminum threaded rod the right size. Coat it with loctite, thread it in until it bottoms out. Cut it off flush with the manifold, centerpunch the new location and redrill and tap your holes.

Don't use metal filler!

The best fix would to be take it somewhere and have it tig welded up though.

The threaded rod method works great when your in a pinch. Another tip about the threaded rod should you choose to go that route.....it helps to rough up the threads alittle before you thread it into the hole. This gives the rod more "bite" into the aluminum. You want to rough up the threads enough to make it hard to screw in. I use a pair of pliers to "booger" up the threads...works like a champ.

Z69

With only approx 1/3 of the threaded rod to remain after drilling.
I'm not to sure how reliable that little junk of left over AL rod would be in this instance.

406TPI

iTrader: (1)

Yeah, that's the point! The less remaining the stronger it will be. Trust me on this one, I am a machinist and have done this MANY times on aluminum fixtures and tooling. It's a perfectly acceptable practice in the trades.

doc

Tim, interesting problem because I have been thinking about switching to the HSR also.

I have measured a few injectors myself just last week. My stock L98 injectors measure 2.68" from middle of oring to middle of oring. My stock LS1 injectors measure 2.56",,, my new LS1 Racetronixs injectors are 2.56"

A drawing that I have on Fords injectors show that this same measurement should be about 2.60".

I would recommend installing FMS injectors or the LS1 version.

I would not attempt to relocate the holes on the fuel rail when the correct fuel injector is available to you.

83 Crossfire TA

iTrader: (2)

I do that kind of thing all the time but I just thread a piece of aluminum rod with the die that matches whatever tap worked in the hole.

I also slather both sets of threads with JB weld instead of locktite, which is just about as strong as aluminum so even if you cut through the side of your aluminum plug you still have plenty of strength.

Honestly, I wouldn’t bother, I’d just take and drill the injector pocket and fuel rail pocket about .035” each (or whatever looks safest, make sure that you clear the wider sections of the injector, which might require you to offset the pocket somewhat), and that way you can use any height injectors in them (they do not have to be all the way down to the bottom of the pocket to seal).

RckyRacr

Tim,
I just put the HSR on my 87 and the stock injectors are to tall. Just like you stated.This is something else. So, you are not alone in this.

RckyRacr

Just talked to Julie at SouthBay Injectors. Very helpful. She is sending the Bosch type 3 injectors. These will fit directly into the HSR with no height issues. SouthBay Injectors are located in New York and the number is 516 492-6504. Julie also mentioned that the stock TPI injectors are not a direct bolt in to the HSR this is why you have to use Bosch type 3's. She also said the Bosch type 3's are of the disc variety and will work up to 80psi.

SuperRamFormula

iTrader: (1)

Just wondering about hood clearance? I take it your hsr intake is on a 87 camaro or firebird. I'm thinking about putting one on my 87 formula and wondering how much of the hood brace I'll have to remove. I don't want to cut a hole in my hood.

Tim Burgess

The HSR just barely rubs on my stock style VFN fiberglass hood - which has no reinforcement structure underneath - so it will most likely interfere with the metal bracing on a stock steel hood. Should not be a problem with a fiberglass cowl hood such as RckyRacr has. Interferance occurs toward the front of the HSR, so one could mill the fins off of the top of the plenum if additional clearence is required, and using a smaller stock style (52mm) TB may help as well.

RckyRacr

Got the injectors that Southbay Injectors recommended. No issues installing them.