ZR-1 Net Registry Forums - 90-92 vs 93-95 IHs

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- - 90-92 vs 93-95 IHs (http://zr1.net/forum/showthread.php?t=15517)

Re: 90-92 vs 93-95 IHs

the end user would need the larger o-ring seals for the 90-92 IH though too

Re: 90-92 vs 93-95 IHs

I'm a little confused, but nothing out of the ordinary for an old fart.

1. 90 IH's can be modified to work with 91~95 heads by drilling out the washer to 3/4" or removing it entirely. other than that, they are identical to 91~92 IH's.

2. 91~92 IH's can fit onto 93~95 heads without modification. Only need to remove lwr o-ring on the primary injectors & insure o-ring is in the IH for the primary injector.

Question: What are you thinking about exchanging? 375 Hp 90~92 IH's for 405 Hp 93~95 IH's? Remember, the 90 IH's can be easily modified to the same configuration as the 91~92 IH's.

Question: Are you saying the 90~92 IH's in stock condition have 34 mm ports compared to 36 mm ports on the 93~95 IH's.... or the other way around?

Quote:

I guess on exchange that puts me in alittle bind as then I am stuck with older models and not many cars can use those...hmmmmm

From this last post, it sounds like you are exchanging the opposite direction, your 93~95 IH's for customers 90~92 IH's.

Re: 90-92 vs 93-95 IHs

Quote:

Originally Posted by A26B (Post 122140)

I agree Jerry, that last post made me confused.

Also you can make the 91-95 IH work on the 90 with a freeze plug and a drill

Re: 90-92 vs 93-95 IHs

Quote:

Originally Posted by -=Jeff=- (Post 122125)

yes.. on the primaries

but the 93-95 will work on the 90-92 just remove the o-ring on the bottom of the injector. you cannot use the 90-92 primary injectors on a 93-95 injector housing.

So just switch to Accels. Probably need to do that anyway.

Re: 90-92 vs 93-95 IHs

Quote:

Originally Posted by A26B (Post 122140)

Question: Are you saying the 90~92 IH's in stock condition have 34 mm ports compared to 36 mm ports on the 93~95 IH's.... or the other way around?

The 90-92 ports are roughly 33mm at the top of the injector housing.
The 93-95 castings are machined to roughly 34mm from the top to about halfway down the port.

Re: 90-92 vs 93-95 IHs

I am asking if its really worth someone to go from a 34mm port to a set of my IHs that are ported to 36mm. The 93-95s breath well, I know about the oil control issues. My only concern was injectors fitting and if it was worth the $ for someone to swap 93-95s for a ported set of 90-92s

Re: 90-92 vs 93-95 IHs

Quote:

Originally Posted by LGAFF (Post 122153)

The late castings certainly have room for improvement in terms of both size and blending around the injector bosses. Whether or not its worth the money is up to the guy spending it, as you know horsepower doesn't come cheap on these cars.

Re: 90-92 vs 93-95 IHs

Lee,
I've ported the later 93-95 plenum and injector housings out to 36 mm
and the ports sure looked bigger than when I started. No doubt they wiil flow much better.