Why you don't put OHV injectors in OHC engine

[jman093]

As always, sorry my pics are so crappy, but I figured I'd take a picture of this while I have the heads off my GTP since I seen this mistake done many other times. Mine has L32 (S3 3800 SC) injectors in it. What your looking at since it's kind of hard to see in the bad pics is that clean, carbon-free spot in the intake port is where the fuel is spraying in. Spraying directly at the wall between the valves, instead of, you know, AT THE OPEN VALVES. It may as well be throttle body injection. LQ1's and other OHC engines have dual pattern injectors to spray the fuel at each valve. I'm going swap these for LY7 (3.6 DOHC) injectors I got out of a Suzuki since they flow a bit more than LQ1 injectors and according to GM have better atomization of fuel.

 

[chadz34]

Definately needs the dual spray.

[z34Phoenix]

wow.... but i ran my l67 (3800 SC series2) injectors in my 96 DOHC for many years with no problems at all. when i tore it all down i did not see that washing pattern on mine. I did port the LIM to match the injectors though... maybe mine had better flowthere and didnt allow the fuel to hit the floor?

 

but yeah if you can get a duel spray injector go for it!

 

here are pics of how i ported it. the first is stock. and you can see where the l67 injector sits.

Edited December 14, 2011 by z34Phoenix

[jman093]

wow.... but i ran my l67 (3800 SC series2) injectors in my 96 DOHC for many years with no problems at all. when i tore it all down i did not see that washing pattern on mine. I did port the LIM to match the injectors though... maybe mine had better flowthere and didnt allow the fuel to hit the floor?

 

but yeah if you can get a duel spray injector go for it!

 

here are pics of how i ported it. the first is stock. and you can see where the l67 injector sits.

 

 

It may have been the porting, but I think it's more likely that there was no washing visible. Engines usually do not unless there have an oil consumption problem carboning up the intake hardcore, which I did.

 

 

Update today. I found out today LY7 injectors are not a direct swap. They are the same body/style as the L32 injectors, but I did not realize they are the short length size, while LQ1 and L67 injectors are the normal length. I had to modify the LIM today to make them fit. I took a grinder and cut the rail mounting holes down a half inch, which then obviously required drilling and tapping the holes deeper. So they should work now. I'm sure BOSCH makes that same LY7 injector (or similar) in a normal length, but I have no idea what it would be (or an application to get one from).

[jman093]

Update today. I found out today LY7 injectors are not a direct swap. They are the same body/style as the L32 injectors, but I did not realize they are the short length size, while LQ1 and L67 injectors are the normal length. I had to modify the LIM today to make them fit. I took a grinder and cut the rail mounting holes down a half inch, which then obviously required drilling and tapping the holes deeper. So they should work now. I'm sure BOSCH makes that same LY7 injector (or similar) in a normal length, but I have no idea what it would be (or an application to get one from).

 

 

I've spent some time searching around the internet and I believe the "better" injectors as GM states that they switched to in 07 for LY7's are the new Bosch EV14 injectors. I found a catalog page with part numbers and specifications to be able to get one with proper 60mm size and flow characteristics without cutting up the intake.

 

http://www.bosch-motorsport.de/pdf/components/injection_valves/EV_14.pdf