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Discussion Starter #1
I've just been comparing some pics from parts eBay. It sure does look like there's a big difference between them.

Big old '97 TLS intake ports just open caverns like an old-school dragster.

2000 TLR intake ports, even these which are ported, seem to have raised floor more noteworthy than hogged-out roof. The 2000 TLR ports look like D-section high-velocity large-radius low-turbulence ports which bend the airflow, and work well across a wide RPM band keeping more velocity at lower RMP and mid-throttle. There's some guy with a website and newsletter mostly about port-reduction with epoxy...these pics sure remind me of that. BTW in these pics he's still got the rubber intake boots on and the viewing angle is a bit different.

Now that I bought the '97 head I'd sure like to compare them side-by-side to later heads. Might do better to port late-model heads alongside the guides than raise the floor on '97 intakes.
 

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The Suck, Squeeze, Bang, Blow Moderator,
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I've never heard of that before so I checked the part numbers of the cylinder heads :-

TLS V = 11100-02F00
TLS W = 11100-02F30
TLS X/Y/K1 = 11100-02F31

TLR W/X/Y = 11100-02F31

The TLS and TLR eventually had the same part numbers.

Would be interesting to see unported pictures from same angle etc to compair :O
 

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Greg,
I remember that Art was experimenting with the adding material to the intake ports on his 97' TLS engine some years ago. Art, you out there? Something about some old dirt track engine builder doing that to old Harley's to increase intake gas velocity. Stuff I remember from the old TL Owners Email list...
 

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Upside Down Super Mod,
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does the TLR have different intake lengths compared to the S? - I would imagine, unless identical inlet tracts, the shape/velocities/charecristics would be dificult to compare directly?
Deosnt the TLR have a higher power band? Maybe its the tract length (cams) more than the heads?
 

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The Suck, Squeeze, Bang, Blow Moderator,
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The TLR has shorter intake lengths by virtue of the shorter Throttle Bodys.
 

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Ports

The 97S has the biggest ports. Tim Widell working at Yosh at the time reduced port volume on their bikes and gained midrange without losing power. The factory then did it to the production heads. I did this to my 97S and got over 140hp.
 

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Discussion Starter #8

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adavis said:
The 97S has the biggest ports. Tim Widell working at Yosh at the time reduced port volume on their bikes and gained midrange without losing power. The factory then did it to the production heads. I did this to my 97S and got over 140hp.
But thats also with cams and big bore right? Was there a noticable difference in midrange from only the D shaped port job?
 

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Discussion Starter #11
It would be very interesting to carefully examine both castings side-by-side. I still think the 1997 had more top than any other, but I could have been misled by how it hit in comparison to a weaker mid. IMHO the difference does explain some peoples' disappointment swapping late-model TLR engines into 1997 TLSs.

But if I want more top from my 2001 TLR, (if there's enough metal) it might be better to slightly port the roof and sides of late-model intake ports (flattening wider at the bend, widening the ports around the sides of the guides and stems, increasing the average bend radius of the airflow by raising and rounding the roof a bit when possible, but leaving a raised flattish floor along the inner radius of the bend like "D" ports) than it would be to weld-up or add epoxy to the floors of early-model intake ports. Easier to grind away than build up. Remember those Micron pipes that flattened at the bend? That motoman.com guy has some rule-of-thumb for port area as percentage of valve area...is there room for larger valves & seats, so that ratio is maintained?

Is the old dragster idea of enlarging a chamber behind the valve is obsolete now that ports flow better? Art, did you do anything to shape the area just above the seats?

Oh well, I'm just a dreamer unless I get some sudden inheritance.
 
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