Is this fuel rail OK?
#1
Senior Member
![](/mt2011/images_td/ranks/supporter1.gif)
Thread Starter
iTrader: (4)
Join Date: Jul 2009
Location: Seattle
Posts: 798
Total Cats: 24
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I bought an FM dual feed fuel rail from a member and am a bit worried about the alignment. Here is the new rail:
![](https://www.miataturbo.net/attachments/engine-performance-56/33928-fuel-rail-ok-p2087641.sized.jpg?dateline=1328765340)
And here is the OEM rail with the same exact injectors and spacers:
![](https://www.miataturbo.net/attachments/engine-performance-56/33929-fuel-rail-ok-p2087642.sized.jpg?dateline=1328765340)
Notice how the FM rail puts the injector at a slight angle while the OEM rail is perfectly straight? If I had installed this with the engine in the car and not had the point of view shown in the photo I wouldn't have thought twice about it. The angle is about the same from either end. Is this a machining inconsistency or are there some variations on the 1.8 heads? The 1.6 fuel rail is MUCH different, isn't it? This rail reportedly came off a working '94. The head in the photos is a BP4W from an '04 MSM. The injectors are 600cc Deatschwerks. The spacers are both in position with all 3 bolts snugged down in each picture.
Thanks for any opinions or suggestions...
![](https://www.miataturbo.net/attachments/engine-performance-56/33928-fuel-rail-ok-p2087641.sized.jpg?dateline=1328765340)
And here is the OEM rail with the same exact injectors and spacers:
![](https://www.miataturbo.net/attachments/engine-performance-56/33929-fuel-rail-ok-p2087642.sized.jpg?dateline=1328765340)
Notice how the FM rail puts the injector at a slight angle while the OEM rail is perfectly straight? If I had installed this with the engine in the car and not had the point of view shown in the photo I wouldn't have thought twice about it. The angle is about the same from either end. Is this a machining inconsistency or are there some variations on the 1.8 heads? The 1.6 fuel rail is MUCH different, isn't it? This rail reportedly came off a working '94. The head in the photos is a BP4W from an '04 MSM. The injectors are 600cc Deatschwerks. The spacers are both in position with all 3 bolts snugged down in each picture.
Thanks for any opinions or suggestions...
#2
Slowest Progress Ever
![](/mt2011/images_td/ranks/supporter1.gif)
iTrader: (26)
Join Date: Oct 2007
Location: The coal ridden hills of Pennsylvania
Posts: 6,028
Total Cats: 304
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
First question I have is: Does the '94 head share the same fuel rail mounting angles as the '04 MSM head?
All I see is that it doesn't look like your new rail is lining up the way it should be.
Look at the way the injectors angle. The stock rail is perfect. With the FM rail, it angles the injector closer to the lower IM. It's as if the injectors are too long for that rail.
Mind is blown.
All I see is that it doesn't look like your new rail is lining up the way it should be.
Look at the way the injectors angle. The stock rail is perfect. With the FM rail, it angles the injector closer to the lower IM. It's as if the injectors are too long for that rail.
Mind is blown.
#3
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
as far as I know the fuel rails are different. At least all the 99-00 head swap information I read said I you need the fuel rail from a 99-00 head.
edit: info from http://www.mx5atlanta.com/forums/showthread.php?t=13121 for example.
edit: info from http://www.mx5atlanta.com/forums/showthread.php?t=13121 for example.
#4
Senior Member
![](/mt2011/images_td/ranks/supporter1.gif)
Thread Starter
iTrader: (4)
Join Date: Jul 2009
Location: Seattle
Posts: 798
Total Cats: 24
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
as far as I know the fuel rails are different. At least all the 99-00 head swap information I read said I you need the fuel rail from a 99-00 head.
edit: info from http://www.mx5atlanta.com/forums/showthread.php?t=13121 for example.
edit: info from http://www.mx5atlanta.com/forums/showthread.php?t=13121 for example.
94-05 MX5 NA8 NB8 1.8 1800cc BP series engine
90-94 323 Familia GT GTX 1.8 1800cc BP series engine
91-95 Escort 1.8 1800cc BP series engine
BP05 BP4W BP6D
90-94 323 Familia GT GTX 1.8 1800cc BP series engine
91-95 Escort 1.8 1800cc BP series engine
BP05 BP4W BP6D
http://949racing.com/m-tuneddualfeedfuelrail.aspx
I guess that answers my question...
![facepalm](https://www.miataturbo.net/images/smilies/facepalm.gif)
#5
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Well, crap. I thought all 1.8 heads were the same in terms of rails. The M-Tuned rail sold by 949 among others lists:
But if you look at the image, it has two channels for the mounting bolts to pass through.
http://949racing.com/m-tuneddualfeedfuelrail.aspx
I guess that answers my question...![facepalm](https://www.miataturbo.net/images/smilies/facepalm.gif)
But if you look at the image, it has two channels for the mounting bolts to pass through.
http://949racing.com/m-tuneddualfeedfuelrail.aspx
I guess that answers my question...
![facepalm](https://www.miataturbo.net/images/smilies/facepalm.gif)
Thread
Thread Starter
Forum
Replies
Last Post