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R1 Carbs (lots of pics)


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You would think so after all  a larger displacement engine is using the same amount of air as a higher revved smaller engine, but Bogg Brothers page on the Ri swap said the jets were enlarged for a larger displacement. Maybe they were borderline lean on the smaller displacement? If/when I go this route I definitely will have a wide band and take it's readings as law.

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  • 1 month later...

I wanted to update my install after I've more or less gotten the bugs worked out. As stated a couple of posts above, I went with the FZ1 side draft carbies and made a manifold to suit for my 610 Wagon. I am currently running the following for jetting on a stock L20B:

Main Jet: drilled to 1.6mm

Pilot Jet: Stock

Pilot Adjustment Screw: 1/6 turn out

Needles: Stock

Needle Position: Moved down 0.68mm from stock. (I did this by removing a washer and filing the phenolic spacer on the stock nonadjustable needles.)

Air Bleeds: Stock

 

I tuned it using a Wideband, and at a 75 degree ambient and at 890' above sea level I get the following AFR readings.

Idle: 12.5-13

Cruise: 14.5-14.7

WOT: 11.4-12.6

 

I've left the tuning as is for now. I will likely have to re-address when I add the rear mounted turbo.

IMG_9552_zps0f5rmwat.jpg

 

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G-Duax, to be honest I'm not sure. The filters are a tight squeeze to get in there. I had to collapse the rear portion of the rear filter to get it between the booster and the throat of the carb when installing. At the closest point I have 3/8" clearance between the filters and the booster so if it does contact it isn't very frequently nor very hard. I plan on ditching the filters in the long run for a plenum so I can force feed these bad-boys.

 

Mike, I'm currently running without the vacuum advance. I have the initial timing set at 15 degrees BTDC for right now. I plan on picking up a CB Performance black box and integrating it with the stock points dizzy to provide timing control in the near future. However, I probably wont pull the trigger for that purchase until just before I'm ready to mount the turbo.

The PCV valve/system is currently TBD. I have both the crank and valve cover vented to atmosphere with filters. I thought about using an exhaust venturi setup, but I'm not sure how it would react being placed before the rear mounted turbo. The PCV system is something I really need to hash out but I haven't.

 

I'm pretty sure it's a 79' engine. It has the round exhaust ports. I replaced the motor about a year ago due to loosing compression on #3. It had a dropped a valve seat on that cylinder when I bought the car that nicked the piston. I put a new head on the car but I think the Hitachi had it running so lean it may have caused a hot spot where the nick was. I haven't torn the motor down to check. I bought the motor off a guy that said it came out of a "truck", all I know is that it runs like a top.

I'm not terribly familiar with the 4 cylinder L-series so is the later motor of any significance?

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I run the vacuum advance, but have the adjustable pod on the distributor, and have the screw turned in so to actually have very few  degrees being pulled in at high vacuum.

Do most advance mechanically, and have it set at 34 degrees total. Probably could pull 36 degrees if I run 92 octane.

 

Have never run a pvc, just vent the fumes, but being in a warmer climate, I don't have a moisture problem, as long as I run the engine up to operating temp every time it goes out. Keep in mind that the pvc was a knee jerk add on to cut pollution on 'merican V8s that had a lot of blow-by, even when new back 50 years ago. Ring design has improved greatly since then, and the fact that an L-series is designed better than a small block pos, means less pollutants.

 

I also run a crankcase vacuum set up when I have a finished project, that uses exhaust flow to evacuate the crankcase (pull a vacuum) at speed.

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  • 3 weeks later...

One of the factors for going to bike carbs for me besides price was the fact that the FCR down draught carbs cleared the master cylinders. As a race car the lack of a vacuum advance wasn't an issue for me. I've been running bike carbs for 8 years now and find them much nicer than DCOE carbs.

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  • 3 weeks later...
  • 2 weeks later...
On 11/15/2018 at 2:00 PM, crewdogch47 said:

Hi guys does any one have 3d files for the l16,l18,l20 intake for bike carbs? 

 

I have this..exported from a 3d printer file I made. The holes for bolts, cooling and ports are shown as .25" here and are used for location. I printed them this way and used a center punch to mark where I'll drill the actual holes, each of which are obviously not 0.25" diameter in the end. Port size depends on your head. I printed 2 separate, traced the outline, punched at each hole location and variously used a bandsaw and drill to rough out each flange.

l16intakeflange-1.jpgIt's 

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for aluminum tig, you want AC so that the electrode positive half of the cycle breaks up the oxidation layer (cleaning) on alumnium surface and allow negative half of the cycle to get through that layer and put the heat into your metal. AC tig machines that can supply enough current for thicker aluminum get expensive though.

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I've always been able to track down someone local that would weld up one of my aluminum projects.

Something small, like a 4-cylinder manifold is typically $50 - $75.

The blower manifold for my 6-cyl Toyota was $100 (20 years ago, so figure $200 these days).

Still cheap for a one off, that I see hot rod shops charge $1000 for a pre built one for a pig-iron V8.

Just have everything pre-cut & fitted before taking it to them, and if alignment is critical, then everything marked, or a pre-made jig of some sort.

And don't use steel cutting tools for any surface to be welded, or if that is the only way you can, take abrasive paper to the surface that needs to be welded.

Microscopic iron particles raise hell with Tig welding aluminum.

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That is almost a must Mike, and only use abrasive paper, or stainless wire brush type tools.

And do it just before you weld.

If you do it one day, let it set over night, the aluminum will start to oxidize, and cause problems.

Edited by G-Duax
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  • 3 months later...

I'm getting close to having everything I need now to start putting it all together but have some dumb questions for you all:

 

On the carbs, do I just need to run a fuel inlet and that's it? I hear the breather tubes can be left alone but can I block them or put a small filter on them etc? Looking to tidy it up. Is there a fuel outlet and does that need attention?

 

I'm going to run an electric vac line to the brake booster and so I'm right to get vac ports on every inlet port for the advance yea?

 

Finally, have you guys mounted your fuel pumps near the tank or in the bay as I've heard bike pumps prefer to push rather than suck if that makes sense. Thanks

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6 minutes ago, frank88 said:

I'm getting close to having everything I need now to start putting it all together but have some dumb questions for you all:

 

On the carbs, do I just need to run a fuel inlet and that's it? I hear the breather tubes can be left alone but can I block them or put a small filter on them etc? Looking to tidy it up. Is there a fuel outlet and does that need attention?

 

I'm going to run an electric vac line to the brake booster and so I'm right to get vac ports on every inlet port for the advance yea?

 

Finally, have you guys mounted your fuel pumps near the tank or in the bay as I've heard bike pumps prefer to push rather than suck if that makes sense. Thanks

 

carb vents need to be left open

 

there should be no fuel return line but in some rare cases I have seen one

 

electric vaccum line?  Not sure what you are trying to say here.  Regarding vac advance the optimal setup would be to run a line from each runner to a small vac canister and then run a line to your vacuum advance- this will dampen the pulses.  you can run a vac line from a single intake runner to the vac advance canister as well, in all truth you may not notice much difference.

 

always mount your fuel pump as close to the bottom of the tank as you can, no fuel pump "prefers to suck".  Space constraints may not allow an ideal mounting location but get as close to the bottom of the tank as possible.  Also, mount your fuel filter AFTER the pump, yes it leaves the pump open to contaminants, but it will also work better, you're more likely to ruin a fuel pump from placing the filter before it rather than after it.

 

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Just now, frank88 said:

Thanks for this. Electric vac pump is mentioned a couple of pages back for the brake booster so you can run vac lines from inlet runners just for the advance



I thought he may have meant an electric vacuum pump, but it would be simpler to just change his master cylinder, run a vacuum canister, or run hydraulic assist.

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1 hour ago, ap72license said:

...but it would be simpler to just change his master cylinder, run a vacuum canister...

 

Change my master to which type?

 

Surely the vacuum canister would only be used for vacuum advance and not for the booster as well so wouldn't solve the problem?

 

Cheers

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