Opening Intake ports with the heads on the bike

[GoFast.....]

Has anyone ever done it. I am thinking of putting a manifold on a 98" that is 1.710

[wfolarry]

It's not worth the trouble. Couple years back S&S decided to make their manifolds '1 size fits all'. Said they tested it & there was no difference in power. Being the non-believer I am I decided to test it myself. On the flowbench - no difference. Dyno - same thing. This was their new style not the old one. That one would have fell flat on it's face. If it's a good manifold there won't be much difference if any. If it's a bad manifold then you have to start from square 1.

[GoFast.....]

I want to move from a 1.6 something to a 1.710

[Admiral Akbar]

Unless you can guarantee that the flow is going to change and get better its not worth it. I tried this some years ago on my 116 with a set of heads that 2 inch intakes and 1.64 port.. Mated from a 1.6 SnS to a 1.80 SnS and got 0 difference in performance on the dyno.. Told me that the flow restriction wasn't there.. Max

[wcgrinder]

Are you wanting to port the heads on the bike?

[Don D]

As your head porter.
I would be inclined to discourage it..
Potential gain VS potential loss.

[Faast Ed]

Are you wanting to port the heads on the bike?

I think he only wanted to open up the area that meets the intake manifold.

[mayor]

As your head porter.
I would be inclined to discourage it..
Potential gain VS potential loss.

Don, did you do the BBB 98" WT heads? 

[Mike52]

As your head porter.
I would be inclined to discourage it..
Potential gain VS potential loss.

Don, did you do the BBB 98" WT heads? 

This should be interesting.

[wcgrinder]

Difficult to keep contamination out.Performance gains would Nil with the stock bowl area.

[JK]

Ditto what Larry said.  Did the same tests at Zippers, same results (no difference).  Just bolt it on, be sure to use the correct (thinner) seals.

[Admiral Akbar]

JK,

With a 1.710 port size, wouldn't the spigot OD still be something like 1.810-20? Could still use the regular seals.. The 1.780-1.800  ports use a 1.880-1.900 spigot and need the thinner seals. Max.

[JK]

Best to check the OD as you said.  If it's the larger OD, 1.880" or thereabouts, use the thinner seals.



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[Faast Ed]

I do believe the HPI's want the thinner seals regardless of diameter.

[jsachs1]

I think HPI uses a 1.880" od manifold,no matter the id.You need their seals.
Harley Davidson makes a seal for their 44mm.style manifold,and early SE 50 mm. throttle body. Seal pt.# 27035-05.
John

[Admiral Akbar]

I think HPI uses a 1.880" od manifold,no matter the id.You need their seals.
Harley Davidson makes a seal for their 44mm.style manifold,and early SE 50 mm. throttle body. Seal pt.# 27035-05.
John

Good to know.. Are the 27035-05 thin like the SnS?  That'd be real good to know when you run out around here.. I don't think anyone, even the indys stock the SnS. Bruce

[wfolarry]

^ I do.

[fuzznut5197]

Unless you can guarantee that the flow is going to change and get better its not worth it. I tried this some years ago on my 116 with a set of heads that 2 inch intakes and 1.64 port.. Mated from a 1.6 SnS to a 1.80 SnS and got 0 difference in performance on the dyno.. Told me that the flow restriction wasn't there.. Max

So, (1.80 - 1.64)/2 = .080" lip around the circumference. I'm looking at my dial caliper, and it looks like quite a large difference. But if it doesn't do squat to match it, then I learned something today.
Thank you, thank you very much. 

[jsachs1]

Bruce,
The MoCo seal falls in between the stock and the S&S.
John

[GoFast.....]

I'll just say a bigger intake port with a bigger manifold with the right intake valve will increase flow and will show on the dyno