Shovel Project Harley Shovelhead Discuss Shovel Project in the Classic Harley Motorcycles forums; All that looked good on the weights, so I dont need to replace that... but the rust on the springs... back in the day, when we did chevy distributors, we ...

[unclepsycho]

All that looked good on the weights, so I dont need to replace that... but the rust on the springs... back in the day, when we did chevy distributors, we replaced them when they got rusty.... maybe we didnt need to??? maybe I dont need to now... she seemed to run ok.
Next weekend I will road test it again. (since I work till past dark now) I think I will install mufflers since it has straight pipes right now. I could get them slip in baffles...keeps the straight pipe look.

Somewhere I heard that I could use EVO exhaust gaskets...just cut off the extra hole....

[frisco-rigid]

Hi Unc

EVO exhaust gaskets fit inside the heads and have NO holes at all,, what gaskets are you thinking of..

They will seal up just fine if you mount the Headers how I told you before..

Simply get some slip-ons OR get a couple 1.750" ID X 2.25" ID or 2.5" ID exhaust adapters..You can get all this stuff at AutoZone, Checkers, etc..

Slip in an exhaust pipe "blank" of the adapters larger ID and weld.. Then add an "end-cap" adapter.. Weld on a couple mounting bolts/studs to use with some 3-piece clamps on the frame or whatever,, and you have Muffs..
Before you weld on the "end-cap", drill a hole for the Washer Trick or add a baffle that fits.. You weld so the choice is yours..
If you slip the header end a wee past the narrow part of the adapter you create a kinda "reversion" cone to help prevent reversion back flow from getting back into the header..
I'll send you a photo if you like..

As far as the S&S B..
The OEM carb that came on that sickle was 36mm venturi Bendix,, I still have one..
A 38mm will run very well but that 39.6mm B is simply tooo big..
Not enough velocity though that huge Venturi.. Your choice..

Have a ball

[Bigincher]

Hey Limpy, how ya been? Always nice to have you come in and be so pleasant about sharing your irresputable and one-minded indisputable my-way-only kind of knowledge. Maybe it's the booze, huh?

[unclepsycho]

I saw somewhere about an evo gasket working... but I spoke without taking mine apart and looking first...so I dont know what either look like YET!!! I have both kinds of bikes... but the EVO bike runs fine... no reason to take it apart. The Shovel leeks so I will have it apart soon.

I dont know where I got the info that there was some kinda evo trick to do on a shovel. I seem to think it was on another site that I no longer visit....like hotbike or something....

I'm gonna save for a MIkuni. I think the Mik 38 will be just fine.

[unclepsycho]

Originally Posted by frisco-rigid

As far as the S&S B..
The OEM carb that came on that sickle was 36mm venturi Bendix,, I still have one..
A 38mm will run very well but that 39.6mm B is simply tooo big..
Not enough velocity though that huge Venturi..

Funy I thought about putting a ring in there to constrict the opening to bring it in smaller...
Could turn it on the lathe so it is tapered etc....

I think I will just get the Mikuni

[1haugster1340]

When I bought my '81 Shovel it had the top end rebuilt with 10 over stock compression pistons. Everything else was stone stock. It had the S&S B on it when I bought it. It ran too rich so I put a smaller main jet in it and it never gave me any problems. The bike ran like a scared rabbit. Would the 10 over have made the motor big enough to handle the B?

[frisco-rigid]

Hi Haug

In the 70's I was one of alota guys in the North Bay that got B's for our 74's..

Mine ran great too once my speed and the Rpm's got high and under stout acceleration but cruising round city streets we all got missing & gurgling unless we kept High R's..

So, I called S&S and talked to a tech named Dan,, talked a few times over the years..
He said it was "dilution" caused by tooo big a venturi for a 74"..
He explained dilution but,, too many years,, I don't remember it..
He told me that even though S&S didn't print it, they did not really recommend a B for smaller than 86"..
I cannot verify that conversation however..
Lucky for you,, it just worked better..

It's interesting that when you changed the Main you got better perf.. The Main in the B doesn't "come in" till 3500 Rpm,,, were you rolling mostly at high R's..?
I just recalled this,, Dan told me to try this experiment-- remove the main jet and plug the discharge tube and run.. He said it would run perfect till about 3500 then would go no further,, I never tried that one,, I just took his word for it..

I suppose you never ran a 38mm on your 1981 so you don't have a comparison..

Several years ago I put a 38mm Keihin on my 93".. It started and ran waaaay better than the B's and E's I ran on it,,,, till about 60 when it fell on it's face..
That smaller venturi produced such High Velocity the lower speeds were Fantastic BUT the 93" needed more voluum at higher R's..

I've experimented with smaller and tooo big and Waaaay tooo big carbs and realized that everything I've always read about venturi size was indeed true..
I did the experiments so I learned First-Hand, Not just reading or hearing it..

Now---what we need is a true "2-barrel"..
Start rolling with about 36mm and slowly another 15mm throat would open up.. Yeah baby..

[1haugster1340]

Originally Posted by frisco-rigid

Hi Haug

In the 70's I was one of alota guys in the North Bay that got B's for our 74's..

Mine ran great too once my speed and the Rpm's got high and under stout acceleration but cruising round city streets we all got missing & gurgling unless we kept High R's..

So, I called S&S and talked to a tech named Dan,, talked a few times over the years..
He said it was "dilution" caused by tooo big a venturi for a 74"..
He explained dilution but,, too many years,, I don't remember it..
He told me that even though S&S didn't print it, they did not really recommend a B for smaller than 86"..
I cannot verify that conversation however..
Lucky for you,, it just worked better..

It's interesting that when you changed the Main you got better perf.. The Main in the B doesn't "come in" till 3500 Rpm,,, were you rolling mostly at high R's..?
I just recalled this,, Dan told me to try this experiment-- remove the main jet and plug the discharge tube and run.. He said it would run perfect till about 3500 then would go no further,, I never tried that one,, I just took his word for it..

I suppose you never ran a 38mm on your 1981 so you don't have a comparison..

Several years ago I put a 38mm Keihin on my 93".. It started and ran waaaay better than the B's and E's I ran on it,,,, till about 60 when it fell on it's face..
That smaller venturi produced such High Velocity the lower speeds were Fantastic BUT the 93" needed more voluum at higher R's..

I've experimented with smaller and tooo big and Waaaay tooo big carbs and realized that everything I've always read about venturi size was indeed true..
I did the experiments so I learned First-Hand, Not just reading or hearing it..

Now---what we need is a true "2-barrel"..
Start rolling with about 36mm and slowly another 15mm throat would open up.. Yeah baby..

Hi, Frisco
I believe you that the carb is too big for stock motors. Maybe it wasn't the main jet that I replaced, as per our local independent wrench the one I changed was the one that was in the middle of the carb body, after removing the bowl and looking straight up into the body of the carb. If I remember correctly I took out a 78 and I put in a 73. ??? If it was hot and I was stuck in traffic, after about 10 minutes the engine would start to backfire through the pipes. That was the only time I ever had any trouble. I talked with people who had stone stock bikes that would do the same thing in this type of situation. ??? Though I did run the that bike at high R's sometimes the majority of my riding was/is at normal cruising speed's. I had the stock carb but never put it on the bike.

[unclepsycho]

I was gonna try my Mik-45 on there.
Seems like we discussed this, and it was decided that it should work fine... since the bike will only draw as much air as it needs....(I wish I could remember the thread)
Is that due to the slide... does the slide make it a "variable venturi"? (my words) with the max opening at 45mm.

I will hafta buy a flange for it to adapt from the manifold to the carb.
Or
I can make one from a piece of flatbar, a short length of pipe, and a piece of radiator hose as the rubber sleeve....

I guess I got another shop project for today now....

I will take pics if it works.

[frisco-rigid]

Hi Haug

Yes, that was the Main-jet but it shouldn'ta affected the idling in traffic at all.. Maybe it was still just loaded up tooo rich from your higher R running that day..???????
And back-fire through the pipes after sitting in Hot traffic------ gee, you know,, just hard to tell now waaaaay after the fact and all..
The thing about the B is that until you get up to about 3500 the intermidiate is in charge and That's usually the jet that guys get wrong,, usually waaay too rich.. The Inter comes in just after idle & goes up to that 3500 mark..
I developed a trick to ease the "off-idle" transition and S&S has one for the Later transition..
Gotta remember,, the B is my Fav carb after the Mik..


Hey Unc
"Variable Venturi" is actually the term used to describe the Mik kinda carb..
The adapter you speak of, that fits up to the Shovel/Evo type Manifold, is what I use,, they work perfect and cheap..
I wouldn't hesitate to run a 45 but the 42 is actually what is recommended for a stock Shovel..
I had to use an additional SU "drop-down" adapter to fit my 45 under the tanks.. I believe the 42 slips right in,, not sure however..

This is a long-shot sugg only----- you might ask your bud at Elvis's if he has a good condition old 38mm Keihin,, you know, prob pretty cheap and will give a real good comparison experiment,, might even like it..