TR4/4A Longer TR4A intake manifold on a 3......

[karls59tr]

I have been running the Tr4a intake on my 3 under the assumption that I would get better flow and breathing there. the TR3 carbs are H6 correct? Anyone see a drawback to this setup? I'm running a mild street cam and header as well. Also are HS6's a better carb for these engines? Karl

 

[TR3driver]

To my mind, the main advantage of the HS6 carbs is the elimination of the jet and float bowl seals. With the H6 carbs on my daily driver, it seems I never go more than a year or two without having to change those dang seals.

I've also been told that they flow better than the H6 carbs, but that the difference isn't very much.

Supposedly (again just what I've been told), the curved tube manifold actually flows less up around redline, but improves flow in the midrange. IOW it trades off peak power for more mid-range power. If your cam has moved the usable power band up by very much, the late manifold may be hurting you overall.

But the stock TR3 intake manifold may not fit with some headers.

 

[Bremer]

FWIW, if you have a performance engine in mind and don't shy away from porting:
According to Kastner, there is a definite advantage to fitting the later type manifold. Not because the early type can't be made to flow like the later one, but because it is a lot more work to make it perform as well.

 

[TRMark]

There is an tech article here about this.

 

[6969ronin6969]

Do you have any pictures showing your setup with the longer intake? I am assuming there is no interference with the inside fender?

Thanks,

Eric

 

[karls59tr]

I don't have a pic but you will probably have to "massage" the fender slightly to fit. I made a dent in the fender with a ball peen hammer....nothing major though.