Spacers between UIM and LIM ?

[zarkoff65]

Are there any advantages to using spacers between a 3400 UIM and LIM say 1/2 to 1 1/2" thick .Therm ,enhancing air flow ? If so where might I find said spacers?

[bob442]

i believe there was no gains...how ever there was more to be had from a 3500 upper intake alone IIRC

[Superdave]

Spacers do not enlarge the cross section of the runner, therefore do not increase port flow. They increase runner length which can have a very slight effect on power band but overall there will be little to no gains. The only realistic use for them would be for gaining clearance and/or direct port nitrous nozzles.



Welcome to 60v6!

[zarkoff65]

thanks for the input.Ive ordered a 3500 top-end head kit for my 3400 04 Imp from WOT.Saw a few mentions of the use of intake spacers and wondered why.Im learning a lot by just browsing this site.

[AleroB888]

I made mine out of basswood. A thermal difference is only realized when used with a forward-facing hood scoop, and in that case is very effective. It can actually be too cold in the winter. However, I never tried the hood scoop alone without the spacers. I may eventually try a brake cooling fan on it without the scoop, if I live long enough.

[Superdave]

Phenolic (or any heat insulating material) spacers do sound like a good idea but cost VS gains are very tiny.

When i ran my engine in a FWD config with the 3500 UIM and a good CAI, i could take the car out for hours in the summer and my UIM would be a little above ambient temp. Of course it would heat back up if the car sat in one spot and idled but that's not that bad.


I guess in short, there are better places to spend your hard earned money. You'll be very happy with the 3500 parts, If you haven't already i'd consider a mild cam to make better use of the improved flow.

[zarkoff65]

I have several plates of 0.40 phenolic and time to machine them no prob.As for my build its a 04 IMP 3400 CAI, 1 5/8 headers,2.5" TIGed cat and res into a SLP dual exhaust, 65mm TCE tv,have ordered a 3500 head kit.I have time constraint issues right now have to wait till spring to do engine pull for cam change.Will talk with Ben about choice of cam & parts needed when Im ready.