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-   -   Title change: modding L36 fuel rail to fit L67 topend (https://www.gmforum.com/performance-brainstorming-tuning-96/title-change-modding-l36-fuel-rail-fit-l67-topend-268512/)

agrazela 11-27-2007 12:57 AM

I am aware of the Dorman offerings, I'm just unsure what might work...do you know if these quick disconnects fit the L67 fuel rail?:

http://www.amazon.com/Dorman-800057-...6142054&sr=1-1

http://www.amazon.com/Dorman-800058-...6142100&sr=1-1

And would these unions work for joining nylon fuel line?

http://www.amazon.com/Dorman-800011-...6142301&sr=1-1

http://www.amazon.com/Dorman-800012-...6142342&sr=1-1

roadtech195 11-27-2007 01:26 AM

I don't mean to sound ignorant or anything but why are you doing this? Will you gain anything buy doing this? Just curious, and I am highly interested in your project. Sorry for the iteruption ;)

agrazela 11-27-2007 01:43 AM

Ultimately, I'm trying to figure out a way to swap an entire L67 top end onto an L36 bottom end without paying $400+ for blinged-out aftermarket fuel rails :lol:

Although with injector spacers, it may be that the L67 rail could be run with the L36 setup (plus L67 heads; blocking the injector holes in the L36 LIM)...whether that's possible and if there's any benefit to that will be tested before the full swap occurs.

(Oddly, while many top swaps have been done, no top swap writeup or thread I've ever read has really talked about how the L67 rails were hooked up to the existing L36 fuel lines; so maybe it is just so simple that no one bothers to mention it)

Ideally, I would like to be able to easily swap back and forth between the L36 and L67 fuel rails, for those brief times--once every other year--when I must temporarily swap the L36 UIM/LIM back in ;)

This "swappability" I'd like is the thing that seems to be making this idea difficult (or at least, more costly), as it would likely require some kind of expensive, in-line quick disconnect fittings.

agrazela 11-27-2007 12:27 PM

2 Attachment(s)
OK, I know it's not good netiquette to post right after yourself, but I had a new idea.

(First, to make it clear, the objective here is to put L67 heads (with injector holes) on the L36 bottom end, then find a reliable, inexpensive way to provide fueling once the L67 LIM and M90 are swapped in)

So, how about modding an L36 fuel rail to fit over an M90?

Assuming that the injector spacing and insertion angle in the L67 head is the same as in the L36 LIM...

What if I took an L36 fuel rail, cut it (at the red arrow in the pic), then lengthen that "cross rail" by some 2 inches somehow:
Attachment 38471

What would be a good way to lengthen this section? (High pressure fuel hose and some clamps comes to mind, though I wonder about safety with that)

Alternately, going back to something Mike mentioned earlier, what if I bent the rail out straight (at the green circled sections in this pic), then bent it back down again an inch or so further out on each side:
Attachment 38472

Then use some 1-inch injector spacers between the rail and the injectors?
How hard is it really to safely bend the rail?

I see no other fitment issues apart from the fact that I would have to cut out a small section of the EGR heat shield (because the rail would then hit it); however, I like these ideas because I would not have to mod the current fuel lines in any way (I believe they would have enough flex to bend into place), plus it would be the cheapest (and possibly the most reliable) option ;)

So, what do you think...would a modded L36 fuel rail fit over the M90 properly?
Which modification option (cut or bend) would be better?

95naSTA 11-27-2007 12:50 PM

This isn't real specific to your last post but I do recall someone cutting, flaring, and unioning in hard fuel line to make room for an intercooler.. It was somewhere on CGP..
So, If you are able to bend the L36 rail to the head and get the mounting to the LIM figured out, you could extend the top portion of the L36 rail with hard line.
Or maybe extend the ends of the L67 rail to a more desirable angle/location.
I would just stay away from teh rubber hose.

I think the main reason you never hear about anyone modding the fuel lines is because they just loosen everything up and get it to reach without kinks.
I did something similar to the opposite of what your doing. I made the stock S1 L67 fuel lines reach my L36 fuel rail.

pontiacjeff 11-27-2007 01:32 PM

Alright, now that you learly stated why you are doing this, you can do it two ways:

Buy my modified L36 fuel rails:

http://www.bonnevilleclub.com/forum/...=asc&start=203

Or make the L67 rail work with your car using these parts:

One 5/16" GM/Chrysler straight coupler, one GM/Chrysler 3/8" straight coupler, one 5/16" repair fitting (striaight union), and the wrench/tool to swedge the union into the lines. The stock lines cut off should reach up ot the L67 fuel fittings, so just put on the correct ends.

agrazela 11-27-2007 03:57 PM


Originally Posted by 95naSTA
So, If you are able to bend the L36 rail to the head and get the mounting to the LIM figured out, you could extend the top portion of the L36 rail with hard line.

I think I'll get the mounting to the LIM figured out with some brackets fabbed from aluminum flat bar stock. Then maybe some flaring, some fittings, and some hard line or braided line. Hmmm...


Originally Posted by 95naSTA
Or maybe extend the ends of the L67 rail to a more desirable angle/location.

I could be wrong, but I don't really see that as practical for what I want to do...


Originally Posted by 95naSTA
I would just stay away from teh rubber hose.

Bear in mind that this build will probably never see more than 7 psi boost (so the s/c won't get all that hot), and I did get a great deal on some used 1" injector spacers (so the hose will have some air gap underneath); so what about some really good hose, like this stuff:
http://www.goodyearep.com/ProductsDetail.aspx?id=5144


Originally Posted by 95naSTA
I think the main reason you never hear about anyone modding the fuel lines is because they just loosen everything up and get it to reach without kinks.

You know, maybe it's because the GP's have metal lines running into the engine bay that then change into plastic lines...and that's just way easier to plumb fuel lines off of.

agrazela 11-27-2007 04:08 PM


Originally Posted by pontiacjeff
Alright, now that you learly stated why you are doing this, you can do it two ways:

Buy my modified L36 fuel rails:

http://www.bonnevilleclub.com/forum/...=asc&start=203

Or make the L67 rail work with your car using these parts:

One 5/16" GM/Chrysler straight coupler, one GM/Chrysler 3/8" straight coupler, one 5/16" repair fitting (striaight union), and the wrench/tool to swedge the union into the lines. The stock lines cut off should reach up ot the L67 fuel fittings, so just put on the correct ends.

I now have it in my head that I don't want to cut or modify the current plastic fuel lines, so I'm kinda giving up on the idea of using an L67 fuel rail.

Now that modded L36 rail of yours look like a high-end version of exactly what I'm talking about...looking through your thread, it looks like maybe you got some polished fuel logs instead? (BTW, that build of yours is just too awesome for words)

So, about the modded L36 rail...are the fittings to the fuel lines still completely stock, and in the same general locations (that is, can I use my current L36 fuel lines and disconnects without modification)? How are the rail halves bolted down?

Are you serious about selling it? Are you including the braided line? PM me with a price shipped to San Diego (zip 92123)...

(And if you aren't selling that one, maybe we could talk about you making me one :D )

agrazela 11-29-2007 12:34 PM

OK, so Jeff and I conferred, and while he made me a fair offer for what he does, he's just too pricey for my budget ;)

P.S., I changed the title of this thread to better reflect what it's evolved into.

After taking some measurements, I have decided that the L36 fuel rail does not have enough length in the "crossover pipe" to be bent out straight, re-bent down to fit the injectors into the L67 heads, and still fit over the M90...even using FI spacers. That leaves me with needing to cut the rail, maybe bend it a little depending where I cut it, and fill in the "gap" with something...
(and preferably something safe, yet cheaper than anodized AN fittings and a stainless steel sheathed AN hose)

The shop here at work has all kinds of tools (tubing cutter, tubing benders, flaring tool, etc), and lots of different types of brass fittings, so here goes:

After cutting the FR tubing, would it be safe to use ferrule-type brass compression fittings, like these:
http://www.plumbingsupply.com/compress.html

Or am I better off with brass flare fittings, like these:
http://www.plumbingsupply.com/flarefittings.html

Assuming I can use one of the above fitting types, I can either choose to terminate in hose barbs and "fill the gap" with high-temp, high pressure fuel injection line with clamps, OR I can choose unions and fill that gap with metal tubing.

Assuming I use metal tubing, we stock B-88 type K thick-walled 3/8" copper tubing...would that be OK in this application, or should I get some brass tubing?

pontiacjeff 11-29-2007 01:08 PM

DOUBLE flare fittings. Make sure they DOUBLE flare the tube or it will leak.


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