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BP4W Injector Port Plugs?

8K views 15 replies 10 participants last post by  ricardo.castilla 
#1 ·
For the guys using ITBs that relocate the injectors from the head on the BP4W to the throttle bodies (Jenvey):

How did you plug the injector ports at the head?

I'd rather not leave the injectors in place on the head AND have the injectors on the ITBs.
 
#3 ·
There are freeze plugs that will fit in the unused injector holes perfectly. I purchased them at my local auto parts store.

On my 95 head, they pressed in tight. On my 99 head, there were a bit loose for my liking, so I used a dab of silicone. The freeze plugs look good, and have proved reliable for me.
 
#6 ·
1/4" NPT fits also if you drill and tap. This is what I did for mine.
 
#7 ·
Is there any reason you want to relocate the injectors? Until you're building an all out race engine the best location for those injectors is going to be as close to the intake valve as possible. Or if building a straight up race engine you'd want them just outside the velocity stacks spraying straight into them, however that would have a significant negative impact on idle quality and low flow/low rpm use, and is best combined with a primary set of injectors located right at the intake valves that operate at idle and low flow/low rpm conditions.
 
#9 ·
Most ITB kits relocate them into the middle of the runners in conjunction with the kit's own fuel rail, so you don't have too much of a choice unless you want to modify the kit.

From Jenvey's website:

Where is the best place for the injectors?

Where one injector is to be used per cylinder the best compromise position is immediately downstream of the butterfly. This gains maximum advantage from local turbulence and gives results surprisingly close to the optimum at both ends of the rev-range. This is the recommended position for most applications.
For performance at low RPM, economy and emissions the injector needs to be close to the valve and firing at the back of the valve head. This is the favoured position for production vehicles.
For higher RPM (very approximately 8,000+) the injector needs to be near the intake end of the induction tract to give adequate mixing time and opportunity. The higher the RPM, the further upstream the injector needs to be. As a result, use of speeds above approximately 11,000 RPM may give best results with the injector mounted outside the inlet tract altogether (see our remote injector mounting). It is common to fit both lower and upper injectors in such a system to cover starting and low RPM, as well as high speeds.


http://www.jenvey.co.uk/jenvey/throttle-body-selection-with-jenvey-dynamics
 
#10 ·
Here we go! Are these hand pressed in, or have to be machine pressed? Do they stay put with just the friction of the O-Ring, or do you need to apply any RTV adhesive? Jenvey has these too, but they are just crazy expensive to ship to the US. I'm glad these are known to fit.

@Leafy:
The Jenvey ITBs have their own injector ports just downstream of the butterflies like Quinn mentioned, and has it's own fuel rail. I have a choice of blocking off the injector ports at the head, the injector ports on the ITBs, or run both injector rails with 8 injectors. I may be completely wrong, but I don't think the MSPNP2 can run 8 sequential injectors (it can have 4 sequential though). In any case, I was thinking blocking off the ones at the head was the best bet to take advantage of the top end gains ITBs naturally offer. I don't mind a slight sacrifice in drive-ability at low end & idle for the equivalent gains at high end, that's why I got ITBs in the first place.....as long as it idles and doesn't quit!
 
#12 ·
I got my BP4W fuel injector port plugs from Maruha Motors via Chikara Motorsport for CAD$ 50.60 + CAD$ 20 shipping. First I removed the old fuel injectors and cleaned the bores with cotton swaps and rubbing alcohol. They are a press fit so I applied Permatex High Temperature Sleeve Retainer as a sealant and installed them using M6 bolt and hammer. Would highly recommend both Maruha and Chikara. I couldn't be happier with the parts.

 
#14 ·
I'm not using Jenvey throttles so I had to source them on my own. Jenvey wants £51.00 to ship 4 little injector port plugs to the USA. That's $84.86 not including foreign currency conversion fees. Their USA distributor Emerald Performance was not very responsive to my e-mail inquiry (took 4 days to respond "call me at the shop" and another 5 days to ask if I still wanted them after I had already told him no because he was too late to reply). I ended up placing my order with Chikara, who only charged $66.65 US. Not cheap, but not too bad all things considered.
 
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