new carburetor setup

[Jim Allen]

The photo shows a Tillotson 19-E carburetor mounted on the isolator block for a rear exhaust QD. The isolator block & the 3/16" aluminum adaptor need to be modified to except the 19 mm (.7480") bore carburetor. The velocity stack comes from Tower Hobbies. A short, very stiff pulse line will be placed between the carburetor's bottom side & the isolation blocks side.

Ja

 

[Patrick Mulvany]

You got me there Jim.

Never knew Tillotson built carbs for small engines?? For that matter I didn't know they were still in business??

Later!!

Pat

 

[John Finch]

Saw it yesterday at the Smithfield race. Looks good.

John

 

[Wally Duarte]

Like the fact you are always doing R&D Jim , would be even better to see some results , just saying

Wally

 

[RaceMechaniX]

CMB also used a Tillotson for the CMB35RS. Carb worked well and remained more consistent than some of the Walboro carbs.

Jim, I machined some bellmouth entries for these, if you want one let me know. 31mm center to center for the mounting holes.





CMB 35RS airhorn.pdf

 

[Dennis Somers]

At SRI we have used the same size carbs on Pioneers, K30s, and J&Gs for 10 years. We mod them, and label them SRI 3000. They are very reliable and responsive carbs.

 

[Jim Allen]

CMB also used a Tillotson for the CMB35RS. Carb worked well and remained more consistent than some of the Walboro carbs.

Jim, I machined some bellmouth entries for these, if you want one let me know. 31mm center to center for the mounting holes.

DSCN1701.JPG

DSCN1700.JPG

CMB 35RS airhorn.pdf

Thanks for the generous offer, but I have been testing this carburetor on my dyno with the OS max velocity stack & the latest tuned pipe. I have modified the stock isolation block on the .7480" round side to flow smoothly into the .8400" X .4800" rectangle side. Doing this makes the total areas of the round & rectangular holes approximately the same. I have added a very short, stiff, pulse line from the isolation block to the bottom of the carburetor. The carburetor works extremely well with tuned pipe pressure & a rigid fuel tank.

Jim Allen

 

[Steve Seebold]

Where does one get these carbs?

 

[Jim Allen]

Steve,

I purchased the HE19-A carburetors from Discount Marine Parts, 4524 D Road, Bark River, MI 49807. Phone 906-466-2180. They also have the rebuild kits for these carburetors. Be aware that there are Chinese copies of this carburetor available on web sites. Carburetors sold by Discount Marine will contain the top plate shown in the photo.

JA

 

[Jim Allen]

I'll have more information concerning the performance of this carburetor with the new, semi curvy type, tuned pipe shown in the photos. The modified OS Max velocity stack was machined to a .748" ID & it does improve the carburetor's performance over the entire engine operating range. The velocity stack cost approximately $25.00 & is easily bored with the fixture shown. The simple fixture shown has a disappearing center pin which is pushed inside for boring the carburetor's bore after bolting the carburetor in place. After pushing the pin inside the carburetor's bore is indicated within .0001" for the boring process. The velocity stack already has a 1.220" center to center bolt hole pattern.

A .0312" thick, three piece, stainless steel butterfly will be added to remove any obstruction in this area. Sealing "O" rings will be added to the butterfly's shaft on both sides of the carburetor body to prevent any air leaks in this area.

NOTE: A special adhesive is being used to permanently bond the machined #360 brass fuel nipple to its #66 Nylon nipple. The same adhesive is used to bond the carburetors brass pulse line nipple to the delrin isolation block. (Bondit tm B-45TH)

Jim Allen

 

[Buckshot]

Current factory carb for the CMB 27 Alpha Evo is a similar unit.

 

[Jim Allen]

Thats correct Buck. There are many similar models around, some manufactured in China that are sold on E-bay. I'm using the Tillotson HE -19A - 525.

 

[Buckshot]

My carb is a Tillotson HE-19A-512

 

[Jim Allen]

This carburetor with a "DECENT TUNED PIPE" would make this engine, even in stock form, very competitive for oval racing!