Gen 1 Intake Plenum on 2nd Gen OHV

[Afrojoe]

Can anyone verify for me that a Gen 1 aluminum intake plenum will fit my 98 OHV? I've heard that the smooth plastic from the Gen 2 may flow better, but I'd really like to convert it to the metal intake both for quality/"Metal! H*ll Yeah!". I'd likely paint it and maybe some light porting. Any of you guys done this yet? Guess if anything I could pick one up and return it if she doesn't fit.

 

[Dono]

No problem with fitment.
No gain in porting the upper. There is improvement to be found in porting the lower.
I don't see why you couldn't paint the plastic upper. The plastic is lighter, so there is also a win there.

 

[Afrojoe]

I've heard some say that the plastic ones fail at some point. I've heard some say 100k,150k, 200k, and then some that haven't had issues. I could paint the plastic one I'm sure, but I don't know that I'd want to sand it to give the paint a texture to adhere too. I mentioned porting because I heard the interior of the aluminum ones are rough which led to decreased air intake, but then again that's not the limiting factor in the ohv is it. Lol. I guess the main reason I want to go to metal is perceived quality/strength of material and to make painting easier along with having a spare plastic one for future use. Since there are no fitment issues I guess I'll look into getting one at my local pick a part and decided based on the price. Thank you for the confirmation on fitment.

 

[benjammin97624]

The intakes do bolt on. I have a question about the egr. How do you get around that in the swap without a check engine light or does it make that much of a difference.

 

[Rhett]

The intakes do bolt on. I have a question about the egr. How do you get around that in the swap without a check engine light or does it make that much of a difference.

If you had a non-EGR plenum it would almost for sure throw a check engine light unless you find a way to dial that out via ECU tune. But you can get a 1st gen intake that has the EGR port on it...

91-92 won't have EGR, early 93/non-Cali emissions won't have EGR, late 93/Cali Emissions will have EGR, and all 94's will have EGR ports in the upper intake mani. So basically if you want to keep EGR you're looking for a late 93 or 94 upper intake manifold aka plenum.

A word of warning, the manifold you find, may have high miles on it. Make sure its EGR port is cleaned out of carbon buildup. It will be a tube cast onto the driver's side of the intake, and if it is clogged up with even small pieces of carbon, it can give you the infamous "EGR flow insufficient" code. Soak the manifold in kerosene overnight to soften the carbon, then use pipe cleaners and high-pressure water to blast it out, or better yet...media blast with walnut shells or similar.