Fueling & Injection - Problem with New Edelbrock XT Pro-flo.

Hey guys, I got a problem I hope you guys can help me with. I bought this XT Pro-Flo to replace my Old Vic Jr. set-up that I wasn't too happy with and felt the XT would better suit my needs, here's a couple shots of it so you get the idea...

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3786.jpg

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3788.jpg

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3791.jpg

Anyways the injectors I have are RC Racing 72lb injectors and they are considered "wide body" when compared to smaller sized injectors. Problem is Edelbrock designed these intakes with narrow body injectors in mind because the fuel rail bracket get in the way of the injectors sitting flush in the injector hole...

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3848.jpg

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3845.jpg

You can see that their bracket covers up the intake grove that was bored into the side of the runner (poor designing IMO)

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3849.jpg

Anyways, I put the brackets on a grinder and cut them down to where they fit better and don't interfere with the injectors...
(This is about half way through the grinding process, they are actually ground down a lot more so that there would be no clearance issues)
http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3884.jpg

Now my problem lies with the injectors hitting the allen head bolt and I can't just grind the heads of them so my question is are there and super low profile bolts I can use? Or does anyone else see a way around my problem? I don't understand why they would design their intake in such a way but it's really turning into a PITA! :rolleyes:
I can get some pictures if necessary of what the injectors hitting the allen head bolts look like.
Thanks for any help.

i know this may sound crazy but how about counter sinking and using countsink screws?

Thanks guys! I think I'm gonna try countersinking them like mentioned and get some screws to match. That should take care of the problem!
Thanks again!

And I look forward to hearing the results...hope its with boost !!!

This is what I've come up with so far, not ideal by any means but we'll see how it holds up. I've thrown around the idea of countersinking the brackets on a drill press and getting some countersink screws but before I do that I chose to shave down the brackets in the following way...

This is my first run shaving off the excess material on the brackets...
http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3884.jpg

After putting them on it cleared the lower portion of the injector well enough but still got hung up on the upper portion of the injector...

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3889.jpg

I put the brackets back under the grinder for one more pass so that they could clear the upper portion of it. While I was there I had originally decided on flattening down one side of the washers, but eventually that became a moot point as you will later see.

This is what the brackets looked like in order to make them fit...
http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3989.jpg

This is with the brackets mounted and the washers on, not aligned yet as you can see...
http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3983.jpg

According to Edelbrock only one bolt is really necessary but because of the hack job I'm doing on the brackets I'm putting two on for the peace of mind it will give me. In reality all they are doing is keeping the fuel rail from popping up vertically which this should do the job.

With the bracket material out of the way the next thing that the injectors hit is the bolts themselves which told me that the Bracket + washers + bolts were too tall of a combination for the injectors to fit...
http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3985.jpg

So I decided to take out the washers completely and put the bolts in without them...
http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3987.jpg

The washers, unless I'm missing something are only there to add additional surface area to the clamping force of the bolt. Their not gonna keep the bolt from walking itself loose/keep the bolt tight. Regardless there was no other way to make the injectors fit so for now, this with a little loc-tight is the best way I can figure short of countersinking the brackets.

Also, prior to the XT I had a Victor Jr. and these injectors worked well on that intake because of the available spacing that accompanied the fuel rail bracketry. I don't have a clear picture of the intake with the injectors in but you can see from this picture all the space provided for in order to fit different injectors.

http://i72.photobucket.com/albums/i189/Flovian/Parts/VicJrwithrails.jpg

The Pro-flow XT was designed for the Edelbrock pico style or the skinny siemens injectors but all injectors that I know of that are this size (72lb'ers) or the larger 96lb'ers that I'm gonna need in a few months are wide bodied in order to house the larger solenoid. So this intake as of now is limited in it's application if I'm not mistaken, no? I don't see what the need was to place the brackets so close to the injectors to begin with. There is plenty of available real estate on the intake to locate two brackets without having to put them so close to injector holes that it was bound to cause a problem. I think over engineering would be an appropriate term here but whatever, no point getting upset over it!

And I look forward to hearing the results...hope its with boost !!!

:nod: It's gonna be something a little different than what were used to but it will be FI.

sorry to hijack,

were did you get the valve covers?

want to sell them?



_____________________
and i am putting this intake on a trailblazzer. so everyone knows. stock size injectors work great

sorry to hijack,

were did you get the valve covers?

want to sell them?



_____________________
and i am putting this intake on a trailblazzer. so everyone knows. stock size injectors work great

The stock injectors should work fine on this set-up, yeah. It's still a hassle to be dealing with this from a company that's got such a great reputation and quality products.

Valve covers were built by a company called ABear. They used to be a sponsor on here but they are now out of business. A friend of mine just got some similar covers but the coil packs are mounted on a bracket outside the valve covers rather than being concealed inside like mine. And sorry but I'm not selling them.

That is a very nice looking intake, looks like you got the mounting problem with the rails all lined out. Cant wait to see what kind of power it makes for you. Then all of us with Fbodies can start cutting and hacking the cowl panels and windshields out of our cars. I have already thought about getting a speedglass windshield and having it water jet cut.

Siemens do 83lb injectors now thin style, and there are some small Bosch injectors at circa 1000cc ( 96lb )

Either will way outperform the RC 750's, which IMO are just ok.


I want one of those manifolds lol

Aren't those Siemens just 60lb'ers but to make them flow 83lbs it's necessary to ramp up your fuel pressure to 80psi or something?

No, they are modified Siemens with the pintle cap re-drilled as far as I am aware.

Although some say there are new 83lb out there used in some Ford, that people are selling, apparently not modified..

Ok kool, thanks.
As far as one injector out-performing the other, are you baseing this on flow tests done on a bench or by tuning, or...? What do you mean by out-perform basically? If need be I could swap these out to something else eventually. Never heard a negative review about them up to now that's all.

The 750's dont spray nice, so make idle etc....not hard, but not as easy to get good emissions levels.

And when I switched from the 60's to the RC 73's, I actually had to make minimal changes to the tune to maintain AFR's


Its part of the reason I dumped the RC's in favour of 2 inj per cylinder...all Siemens of course.

The 750's dont spray nice, so make idle etc....not hard, but not as easy to get good emissions levels.

And when I switched from the 60's to the RC 73's, I actually had to make minimal changes to the tune to maintain AFR's


Its part of the reason I dumped the RC's in favour of 2 inj per cylinder...all Siemens of course.

If you mill that whole bracket mounting pad down a bit further, you should be good to go. You might also need to flatten the bracket a bit, instead of the big "z" shaped offset. (I'm using the same manifold, except in bare aluminum finish, with 160's.)

mine look different then yours.

were the tb goies did you mill that down at all? or cut the gasket gruve?

mine has none of that. i think i got ripped off.

second i cant bolt my ls2 tb to it.

mine look different then yours.

were the tb goies did you mill that down at all? or cut the gasket gruve?

mine has none of that. i think i got ripped off.

second i cant bolt my ls2 tb to it.

I don't wanna say you got ripped off but what you did get was one of the first production runs of manifolds. They didn't run a groove for a TB gasket and they didn't have variety of different mounting holes for the Throttle Body like the later ones do.
They didn't think much about it but Richard @ WCCH, who I bought mine from pressed them into making a groove into the 2nd run of manifolds they made. I would recommend sending your manifold to Richard @ WCCH and he will CnC a groove for you. But you can also just RTV the thing and it will work, just not as well.
He also laid into Edelbrock pretty good about not supplying mounting bolts with their kit... I like edelbrock and they have good products and a good reputation but they were a little anxious to get this product out on the market IMO. Could of done a better job of thinking some of these things through.

All this chit chat.....what about some results !!!! lol

Waiting on some parts from Summit, if all goes well maybe next week. But when do things ever go right? :rolleyes:

My Summit parts got here 2 days early!! Freaking love them! :nod: Started with the Throttle body seal. the O-ring groove was very deep on the intake...

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG4084.jpg

So of course the seal isn't gonna do much good now is it!! http://www.performancetrucks.net/forums/images/smilies/LS1Tech/rolleyes.gif...

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG4078.jpg

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG4079.jpg

I don't have an LS7 gasket so I put some RTV in the groove instead to see if I can make the seal work...

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG4085.jpg

And then put the O-ring in it...

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG4086.jpg

I then put a bead of RTV on the back of the TB so with all that yummy goodness I hope that it seals...if not than I'll be running lean!! http://www.performancetrucks.net/forums/images/smilies/LS1Tech/gr_emb.gif

Here's how she looks now...

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG4087.jpg

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG4088.jpg

Got it bolted up to the heads...Looks kinda mean on there!! http://www.performancetrucks.net/forums/images/smilies/LS1Tech/gr_devil.gif

http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG4111-1.jpg

All I have left to do is finish cutting, fitting and assembling the fuel lines which is gonna take a little time because I don't have a Vice so I'm gonna have to go somwhere else to assemble them. After that it's belts, last of the wiring harness, new spark plugs, wire up the starter and download a tune and hope she doesn't blow up! Oh yeah, and I need to put the headers on!! The last of which should take me less than an hour...hopefully.

Ehhhhh... :(
On second thought, I'm gonna run to the stealership tomorrow and see if I can't get a stock LS7 gasket...that 90mm TB seal isn't gonna do the trick and even if it does I ain't gonna feel good knowing it's in there like that.

Got a new TB seal at GM, it's the LS7 seal, I think this is what Edelbrock had originally designed this groove for! http://www.performancetrucks.net/forums/images/smilies/LS1Tech/gr_nod.gif

http://i72.photobucket.com/albums/i189/Flovian/CIMG4118.jpg

http://i72.photobucket.com/albums/i189/Flovian/CIMG4119.jpg

So off came the TB again! http://www.performancetrucks.net/forums/images/smilies2/icon_rolleyes.gif
Look ma no bolts!! http://www.performancetrucks.net/forums/images/smilies/LS1Tech/gr_grin.gif ...
http://i72.photobucket.com/albums/i189/Flovian/CIMG4115.jpg

RTV didn't make too much of a mess, it actually woulda worked looking back but I'm glad I got the right one in it's place...

http://i72.photobucket.com/albums/i189/Flovian/CIMG4116.jpg

http://i72.photobucket.com/albums/i189/Flovian/CIMG4117.jpg

Spent about 30 minutes removing all the RTV from the flanges and then I stuck the new gasket in...like butter!! http://www.performancetrucks.net/forums/images/smilies/LS1Tech/gr_stretch.gif

http://i72.photobucket.com/albums/i189/Flovian/CIMG4120.jpg

http://i72.photobucket.com/albums/i189/Flovian/CIMG4121.jpg

And then torqued down the TB to 97 in/lbs and called that job done in my book!! http://www.performancetrucks.net/forums/images/smilies/LS1Tech/gr_nod.gif

http://i72.photobucket.com/albums/i189/Flovian/CIMG4122.jpg

I'm pretty sure those ford 83lb injectors mentioned earlier are thin style injectors. They are also rated at 39psi fuel pressure. At 4 bar they flow right around 100 lbs / hr and are high impedance.

Well...she runs finally! :)

http://www.youtube.com/watch?v=r1SNGCSqdNY


http://i72.photobucket.com/albums/i189/Flovian/My%20truck/CIMG4283.jpg

So tell us about it man .... how does it run ??

BUMP - How does it run?

Sorry for not getting back sooner, been in China for a couple months and heading back tomorrow but she runs pretty good! Alot better considering it's a low compression 8.7:1 compression engine running without any boost. Numbers were 314/306 N/A. Same motor with a vic Jr on 18lbs made 730/743 or something, forgot exactly.

http://www.youtube.com/watch?v=ezTy5d5Kklo

http://www.youtube.com/watch?v=SRsXTGzDGZA

any updates?

Ummm...nothing really on the truck itself. I drive it as a DD and scare the crap outta kids and women cuz it's so damn loud. The intake is performing awesome!!! Top end on the truck is a little outta character compared to the rest of the powerband, and I mean that in a good way. I did take it to the track and it did a 14 flat @ 103mph. As you can see the fact that this is such a low compression motor that I'm running N/A this thing has no low end but my trap speed is pretty good, at least good for mid to high 12's if it could actually get the truck off the line.
But aside from that I have a LSX TD sitting on my garage floor and I'm wondering what I'm gonna do with it!! :devil:

http://i72.photobucket.com/albums/i189/Flovian/IMG_0202.jpg

Other than that truck got rear-ended on the fwy and it's getting a whole new paint job, and this summer I'm either gonna rebuild the Forged 370 and add a turbo to it or build a 482ci monster N/A motor. Not sure what I'm gonna do. Whatever's cheaper really.

I am considering this intake on my LQ4 6.0 in my Datsun. Is the TB above or below the top of the alternator? Ask because my alternator is the limit of my hood clearence and if the TB is level or below the top of the alternator, I am good to go.

Thanks!!

Looking through my photo-bucket account and found these two pictures, looks like it's a little higher than the alternator. You could always get a cowl hood no?

http://i72.photobucket.com/albums/i189/Flovian/My%20truck/CIMG4108.jpg

http://i72.photobucket.com/albums/i189/Flovian/My%20truck/CIMG4110.jpg

i know old thread, but why did you swap from the victor jr to the pro flo?

So I decided to take out the washers completely and put the bolts in without them...
http://i72.photobucket.com/albums/i189/Flovian/Parts/CIMG3987.jpg

The washers, unless I'm missing something are only there to add additional surface area to the clamping force of the bolt. Their not gonna keep the bolt from walking itself loose/keep the bolt tight. Regardless there was no other way to make the injectors fit so for now, this with a little loc-tight is the best way I can figure short of countersinking the brackets.



How well does this fit with the bottom bolt removed? I am going to have to do this next week thats why I ask.

How well does this fit with the bottom bolt removed? I am going to have to do this next week thats why I ask.

Depends on the injectors you end up using. Some are fatter than others.

I have the same intake and used FIC 83lb Bosch LS2 style injectors. Had to buy their spacers though cause the injectors was a tad short.