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baggedgoods

Stock Z31 Injector O-Ring size

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Basically as the title says, what is the stock o ring size of the 85 300zx turbo injectors into the intake? Are they 14mm or 11mm? I'm about to order some new injectors and I can't seem to find any information about the size of the bottom o rings. Thanks

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Posted (edited)

I bought the pallnet rails with 11mm ports. I know the top side isn't if issue as much as the bottom side that plugs into the intake.

 

I've had very good experiences with Injector Dynamics and would like to use them, but I've read that it can be rather difficult to get an o ring injector end to fit into the manifold. Any suggestions? Or tips? Maybe fit the o ring with a rubber washer end like the stock injectors have?

Edited by baggedgoods

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Posted (edited)

Some people enlarge the manifold hole, some people devise a sealing method that works with the stock holes.  With a turbo the sealing method is more difficult than NA since there's positive and negative pressure.

 

You shouldn't really be asking about o-ring size, you should be asking how people seal 11 or 14mm injectors to a stock VG30 manifold.  

 

Injector Dynamics might already have a method.  Send them a message.

Edited by NewZed

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Posted (edited)

You're right, I should have worded it differently, but you got it. I'll send them a message and update later. Have you seen any posts about successfully fabricating the manifold? I've been searching high and low but can't seem to pinpoint a post that will answer my question.

Edited by baggedgoods

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You can drill the manifold to fit the injector and o-ring, or or you can add injector bungs. O-rings need a certain diameter and depth of hole to seal the way they were designed to.  But they can also be made to seal like a gasket would, but that's easier to do with NA.  If you had the EV1 14mm injectors you could use the o-ring on the top and the stock seals on the bottom.  Lots of possibilities.  Look at how people did their L series manifolds, your new rail works the same way even though it's the V6..

 

Pallnet might have some thoughts also, since he sells the rail.  You could send him a PM.

 

https://www.google.com/search?q=injector+bungs&site=webhp&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwil_KD8wMDTAhUW32MKHb92AUcQsAQIjwE&biw=1280&bih=890

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http://www.t1racedevelopment.com/category/injector-dynamics/id1050x/universal/id1050x-60mm-length-11-mm-blue-adaptor-top-denso-lower-cushion.html

 

I talked to the guys over at injector dynamics and they needed to know the size of the seal to help me further. With some digging I found this unit, although I'm not 100% sure if this will directly fit into the stock plenum holes.

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Send them one of the stock rubber seals.  They're about a perfect fit for the seat, and the stock injector tip.  They get slightly compressed when the injector is clamped down.

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There's no vacuum under boost.  And they're the stock seal, and appear to work fine.

 

Beside that, send the seal so that ID has the dimensions.  That was my point.

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I meant boost leak** and I've sent them an email of a picture of the seal. I can't find the actual physical size of the seal anywhere. I don't have any seals lying around and I'm leaving the stock injectors installed as I'm currently finishing up my Megasquirt install so I have no seals to send them.

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Posted (edited)

Injector Dynamics injectors for the 1987 Toyota Celica Supra Turbo should fit. Confirm with Injector Dynamics first. Motorman injectors also has the cross reference for sizing between the Supra and Nissan seals. 

 

http://www.t1racedevelopment.com/category/injector-dynamics/id1050x/toyota/id1050x-supra-turbo-87-92-7m-gte.html

 

The mid 80's Supra injectors fit the stock Intake manifold on the 280Z, 280ZX and apparently the Z31 as well. Uses the Denso style bottom seals.  Same as Nissan.  Body square seal is approx 27.8mm ( not installed ) . Bottom tip seal is 13.7-8mm ( not installed ) . So probably 28 mm and 14 mm installed.  

 

The Supra top seal is a standard 11mm O-ring. 

 

You can order the bottom seal kits from Rock Auto. Order the Standard Motor Products SK-4 kit. It's a whole $1.10 ( one dollar ten cents ). Gets even better. RA Info says SK-4 has 2 seals. I small tip seal and 1 large body seal. But when you get the kit, you will find it is a complete set of lower seals with 6 small tip seals and 6 large body seals. Guess how I know..... 

 

https://www.rockauto.com/en/catalog/nissan,1985,300zx,3.0l+v6+turbocharged,1209518,fuel+&+air,fuel+injector+o-ring,13679

Edited by Chickenman

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Shit yeah, same flow rate I'm looking at as well since I plan to be running E85 soon! I guess if I had done some digging and cross referencing, I could have found my answer just like you found it. I'll also double check with Injector Dynamics in the morning. Thanks!

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Rock Auto also carries the phenolic injector holders with new metal retaining plate. SK-37 = $4.55 each . I ordered a bunch of those before they ran out. 

 

I think the Z31 uses the same style injector holder as the 280Z and 280ZX. For JECS style.

 

MSA carries the injector holder screws.  

 

https://www.rockauto.com/en/parts/standard+motor+products,SK37,fuel+injector+o-ring,13679

 

SK37photo%20primary__ra_p.jpg

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So you say the denso bottoms will fit correctly into the stock manifold with no modification? And the rock auto injector holders are for using o ring type injectors with longer pintles?

 

Also, 60mm length injectors seem very standard, and I'm assuming that they should work right with my new pallnet rails and the manifold. Just as long as I get the seals correct.

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