Six_Shooter Posted July 6, 2008 Share Posted July 6, 2008 So in my EFI swap, I am making (maching fuel rail stock to be exact), and have used an Accel 2' fuel rail stock. In a 1973 240Z Originally had Weber DGVs. I have an N42 EGR intake, modified to fit O-ring injectors. F54/P90 (came already installed in car). My problem is the fittings in the end of the fuel rail hit the thermostat housing. Now I still have a bit that I can cut off to move the fittings towards the rear of the car, but I can't remove enough to completly clear the thermostat housing. In looking through some posts on here, it seems there is a difference between the "early" L6 and the "later" L6, I have not been able to find the information that says when this switchover too place. When did that happen? It looks as though the "later" thermostat housing would clear my fuel rail and fittings, due to the bolt pattern being different, I've read that there are 3 bolts, instead of just two that I have, and it looks like the one bolt is moved. It is one of the bolts that is giving me the most problem right now. I have thought about cutting the fuel rail on an angle and welding an aluminium bing to it, to clear the T-stat housing, but would rather not have to do that. Can anybody shed some difinitive light on this for me? I can't seem to find any close up pictures of this area on the L6, what I see is wider shots. If this is what I need, does anybody have a T-stat housing they can spare (upper and lower)? Thanks Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted July 8, 2008 Administrators Share Posted July 8, 2008 I had the same issue with my L-28, N-42 intake, O-ring injectors, (’85 Vette injectors), Mega Squirt EFI. I had the later 3 hole style thermostat housing. I ended up making mine a semi-return less fuel rail and just installed a plug in that end of the fuel rail. I didn’t have any issues heat related or otherwise. Stock fuel routing… My semi-returnless fuel routing… Hope this helps, Paul Quote Link to comment Share on other sites More sharing options...
ktm Posted July 8, 2008 Share Posted July 8, 2008 I had the same issue with my L-28, N-42 intake, O-ring injectors, (’85 Vette injectors), Mega Squirt EFI. I had the later 3 hole style thermostat housing. Hope this helps, Paul That's odd. I am running the same later model thermostat housing and did not have a single issue. Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted July 8, 2008 Author Share Posted July 8, 2008 Thanks for the idea Braap (and for the reply to my PM). I had though about plumbing the fuel system by either feeding the inlet farther down the fuel rail, or pulling the return from father down the rail. Not quite like your "semi-returnless" system. My only worry would then be the #1 injector possibly not getting enough fuel supply. I have seen system plumbed similar though and don't seem to have issues. KTM; it was actually that picture that lead to me look farther into the thermostat housing and possible differences. Does anyone know the year that they started with this "later" 3 bolt thermostat housing? Thanks for the replies. Quote Link to comment Share on other sites More sharing options...
ktm Posted July 8, 2008 Share Posted July 8, 2008 Mine came with the engine, a 1983 L28ET. I would venture a guess that any L28E or L28ET from 1981 to 1983 would have one (basically any 280zx). Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted July 8, 2008 Administrators Share Posted July 8, 2008 Bo, At what depth are your injectors inserted in the manifold? They are the O-ring style top and bottom correct? I bored the injector openings and massaged the injector bosses extensively which sunk the injectors deeper into the manifold. These pics are of another N-42 intake I built for friend using Ford Mod O-ring injectors. Note how much lower the fuel rail sits vs the OE injectors and tubeular fuel rail… Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted July 8, 2008 Author Share Posted July 8, 2008 I think that might be part of my problem as well, my injectors sit quite low in the intake, and that moves the fuel rail quite close to the T-stat housing. I know I can space it up just a bit using O-rings under the body of the injector to space it up just a bit, but still won't be enough to enough to clear the T-stat housing. KTM, I figured that just about any ZX would have the "later" housing, but I hate to assume all of them do, just because they are ZXes. "ass-u-me" Quote Link to comment Share on other sites More sharing options...
ktm Posted July 8, 2008 Share Posted July 8, 2008 Paul, I am running the 7MGTE (Supra) 440cc injectors (11 mm o-ring). I simply used the stock lower o-ring and the 11 mm o-ring at the rail. I do not know just how deep the injectors sit in the manifold. The top of the lower o-ring is flush with the injector body, that is, they are as deep as they can go. The 7MGTE injector "pintles" are not very long, not much longer than the depth of the stock lower o-ring. Six Shooter, I know the old saying, but you gotta start some place. Quote Link to comment Share on other sites More sharing options...
hughdogz Posted July 8, 2008 Share Posted July 8, 2008 To add to BRAAP's Generous posts... You can probably do it...it seems to depend on the length of the fuel rail past the #1 injector: "Newer style" Thermostat Housing: ('82 ZXT) "240Z style" thermostat housing: Hope this helps... Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted July 8, 2008 Author Share Posted July 8, 2008 Yeah that definatly looks like the "later" style T-stat housing would solve my issues, I'm also thinking that I will need to shorten the rail just a bit, to gain a tad more clearance. By looking at the "extreme close up" picture of the T-stat housing (thanks hughdogz), it looks like that bolt boss could be cut off and smoothed out to gain a bit more clearnce for the fittings as well. So it looks like anyone converting to EFI, and using an O-ring rail would have thier best results using the "later" T-stat housing. I'm sure for most people this wouldn't be or hasn't been an issue, because it seems that anyone making this conversion is doing so from an existing (stock) EFI system, that it seems should have (I hate to ass-u-me again) the 3 bolt T-stat housing. Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted July 8, 2008 Author Share Posted July 8, 2008 Well, thanks to jbk240z, we can establish that 1978 has the "early" style T-stat housing. He sent me a couple pictures last night of the T-stat housing from a 1978 280Z. Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted July 19, 2008 Author Share Posted July 19, 2008 Jusat updating that the 1980 L6 has the later style T-stat housing, so at this point we can confirm that 1980 to 1983 use the "later" 3 bolt T-stat housing. Quote Link to comment Share on other sites More sharing options...
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