1980 LTD Street Head stock valves

Here's some pics, charts & numbers.

Stock head signs off at 68CFM @.500" lift @10 Inches.

Intake boots are for BS34 Mikuni


Centerline Pitot readings were taken at .400" & .450" lifts

1&2

1&2

3&4

3&4

1&2 numbers

Sorry but 3&4 numbers pic is too blurry...

ya know thats a terrible thing to do to a guy who just had surgery for a hernia! :woohoo:

Bottom picture showing a blurry 85.6cfm?

Larry, would you get those numbers from a 1st generation Kz head? Or even one that has had J motor valves installed?

porchev914 wrote:

Larry, would you get those numbers from a 1st generation Kz head? Or even one that has had J motor valves installed?

Yes, all the KZ heads, 900 & 1000.

It's a valve size / throat size relationship along with the bowl that will mostly set the pace for the flow.

I've got to the point where if the stock 36mm valves are shot I will quite often just jump up to a J intake because with the shorter J valve it's not all that much more work to sink them where they need to be.

That in turn gives you more lattitude to play with throat size and taylor things for the way the guy rides the bike.... Hope that makes sense

On this particular head, the guy has some old police BS34 carbs. Not my favorite by any means but I completely understand budget restrictions so I just change strategy a bit for things like that.

As far as I'm concerned BP could use all the BS34's advertised on Ebay and plug the leak in the gulf with them..... :woohoo:

Sorry, I wasn't paying attention! :S I was thinking you were working a J head :dry: :whistle:

Correct me if i'm wrong, but you've achieved an approx 25% increase in flow on that head. Is this your street porting, or strip porting Larry? Either way, bitchin looking work :woohoo: