4D56 Injectors

[Yarbo]

I just replaced the head on a 4D56 engine in a Delica and the injector ports in the new head are significantly larger than the injectors out of the old head. the old ones are about 20mm thread (on the outer cup) and the thread in the new head is about 25 mm. from the people I have talked to, there is only one size injector available for this motor. Just wondering if anyone has ever heard of this or knows what can be done with it at this point. Thanks

[Pacific JDM Parts]

I think you have been supplied the wrong head.
The 4D56 only has one size of injectors so you need to talk to your supplier about a replacement head.

[thedjjack]

Hyundai head?????????????

[Rising Sun Auto Import]

Hyundai head?????????????

We have supplied many Hyundai OEM cylinder head to CVI and CCautos, no problem. :

[Yarbo]

Possible it is the wrong head. it was purchased in a private sale, so no go on returning it. All the coolant and oil ports match up perfectly and there is no visual difference other than this. I am looking into the possibility of making a threaded reducer to fit the larger hole. as long as the bottom of the injectors are sitting in the right spot, this should work out.

[jessef]

Perhaps the head that you got was modified.

[thedjjack]

industrial application? Ford application? Must be injectors that fit this head.

[Yarbo]

I think that there would be injectors to fit it but with out knowing what head it is, its is kinda hard to order. Or the other option is that they just made a mistake when they made the injector ports and sold it anyway. I think I am going to make a threaded adapter to fit into the head and fit the original injectors.

[thedjjack]

I would try a diesel injector rebuild shop first. They should have an adapter or advice. If you make something make sure the tolerances are good...lots lots lots of compression in a diesel.

[mdrive]

2 kinds of head available for 4d56, watercooled turbo type and oil cooled turbo type. if you have the wrong one for your car, you will have problems with the valve and piston besides injectors.

[Yarbo]

I have already tried a couple injector shops. they figured my only hope was to build an adapter.
water cooled vs air cooled turbo? any ideas on how you tell the difference in the heads? and if thats the case would there not be a different injector available for teh different head? So far nobody I have talked to has ever heard of a larger diameter injector for this engine at all. Thanks again for the help.

[FalcoColumbarius]

If you go to the shop manual it will tell you how to recognise the right head. Study that one and compare it to the one you have.

Falco.

[mdrive]

If the valves are sticking out at the bottom of you head, it is water cooled turbo type, then the higher pressure injectors are needed. if you valves are flashed to the cyl head, it will be the oil cooled (pre oct 94) turbo type and in that case you will need lower pressure injector type.

[Yarbo]

Here is a couple pictures of the brass seats and the larger diameter thread that we made to fit these injectors into this head. I have it all back together now and it seems to work fine. Having never driven it before it is hard to say if performance is affected but it seems to run excellent. Thanks for the help.

[milky]

Hope my input can help, as you posted in jan.

(In no way am I trying to sell anything here)

I work for a company in the UK that sells cylinder heads. The problem you have is that there is a 4D56 2.5 head and a 4D55 2.3 head, both are exactly the same except for the injector size.

In the UK flush type heads were available from 1993 onwards. Pre '93 there were protruding types. From experience in regards to selling heads to customers in North America, there was 1 gentleman who had a Dodge RAM (if memory serves me correct). His injectors were too big for the 4D56 head that we sold him. We did try to provide some injectors to him but he never came back to us.