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PHM 40's on '98 Cali EV

Carlo Guzzi

Carlo Guzzi

Tuned and Synch'ed
Joined
Jul 9, 2014
Messages
26
Yeah, I know - a bit left field but, does anyone have any experience in jetting PHM 40's on a mid valve '98 Cali EV? Ball park stuff would be appreciated. Current iteration is 57 idle, 140 main, 266AB with K4 needle, 60/5 slides. Has some mild porting and a LM4 K&N airbox.
Runs very lean in mid-range on this jetting combo.
Cheers!

P.S. anyone who wishes to tell me that;
a) Cali EV's didn't come with PHM 40's
b) I have desecrated a beautiful cruiser
PLEASE don't bother!
(Take note : 'The Groper')
 
40s are way over size for that engine. 30 to 36 would be max. The valves and cam just won't work well. To get closer to correct with the 40, you could use the setup I use for 1100 Sports. About the same size jets, but with a 265 atomizer and the K5 needle. It is the needle and atomizer that control mid range, not jets.
 
john zibell said:
40s are way over size for that engine. 30 to 36 would be max. The valves and cam just won't work well. To get closer to correct with the 40, you could use the setup I use for 1100 Sports. About the same size jets, but with a 265 atomizer and the K5 needle. It is the needle and atomizer that control mid range, not jets.
Click to expand...

Thanks John,
I have a B10 cam installed, mild porting and the right size manifolds.
My thinking was that if the LM 850 with mid valves could run 36's then, this 1100 mid valve engine could manage 40's (given the cam/porting/manifold changes).
She went out for her first run today and was actually quite responsive and clean running.

I'll give the AB265's/K5 a go on the 40mm's first but, wouldn't AB265's be even leaner than the AB266's?
Be interesting to see the difference and, if I have to go back to 36's to get a clean running engine I guess I'll do that.
Appreciate the input.
 
40s were used on some late CA IIIs that had the 1000cc LeMans engine installed. Those ran like scalded dogs, but they had the big valves. With you cam, porting and manifolds, the 40s just might perform well, but the efficiency RPM will be higher than with the 30 or 36mm carbs. Have you found this? https://www.guzzitech.com/forums/resources/categories/misc.24/ You will need a spreadsheet program to do the calculations.
 
This is an interesting process.
When I started out, I noted that the EV had 36mm ports and mid size valves but that it also had 40mm throttle bodies. So, the stock EV was (in a sense) already running 40mm with mid valves. Whilst carbs cannot have the accuracy of the EFI system, it did suggest that the heads could take 40mm flow if metered correctly.
(I also noted that the 40mm throttle bodies had a big step where they met the stock 36mm manifolds and port entry - which had to be bad for flow efficiency).
I took the Reno Leoni approach (i.e. big carbs on small ports for Ducati 250 singles) and made sure that the large 40mm carbs 'coned' on to the ports so that there was a gradually decreasing bore up until (just before) the valve guide and thus (hopefully) retaining/enhancing the venturi effect in the port.
Seems to work quite well in terms of retaining responsiveness with excellent pick up in the mid range and not a peaky power band at all.
(I'm sure, as you say, that 36mm carbs would have given crisper mid range response though).

As to jetting, I actually found that I had fitted 138 mains and suspect that this was strangling the needle's ability to flow fuel.
I've made some progress since I posted with current iteration: 145 mains with the K4 on richest setting. This gives a nice light coffee colour from mid range running and is actually pretty good on the transition from idle on to the slide/needle.
Appreciate your input on this John
 
You will find early California 1100s had 30 mm carbs. Basically same engine as the 98 EV. I think the reason for the 40 mm FI throttle bodies were economics. Cheap to purchase. The 1100 carb sports had larger valves and different cam to handle the 40mm carbs. Controlling air flow with a butterfly is different than with a slide. Also the FI mapping should compensate for the air flow (reduced velocity). The injector atomizes the fuel, and a carbs need high air velocity for a good mix. You are part way there with the cam, hopefully things will settle out.
 
Interesting, but according to the Stein-Dinse parts list, the last Cali 1100 before EFI is listed as 36mm carbs and mid size valves?
 
Try a 268 needle jet and the needle clip in the middle position. 140 mains sound about right. Not that you'll ever really be on them during street riding. A California engine with a B10 cam will be a lovely motor. The racing kit for an 850cc Lemans used 40mm carbs with mid valves. A mid valve 1064cc with a cam will be fine with 40's.

People forget a California engine is a big bore Lemans :)
 
Now this response matches my experience with this engine. Even with the mid range lean condition she was responsive and very powerful on her first outing - great pull through the range.
Thanks for the tip, I'll order up some AB268's.
 
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