The Ford Barn

37 ford firetruck · 07-05-2016, 08:34 AM

I am using this carb on a stock 1937 flathead 85 horse. Rebuilt the carb and replaced all gaskets, power value (7.5), new holley jets. (.51), and accelerator pump. The carb performs well but leaks into the intake when the engine is shut off...fills the intake above the throttle butterfly and leaks out of the throttle shaft. I suspect power valve is leaking. Other thoughts would be appreciated.

ford38v8 · 07-05-2016, 12:06 PM

Power valve mating surface is different on new valves. You must machine the surface flat to match the carb. Insure that the gasket is sealing by filling the bowl with fuel and setting the carb on a paper towel/table overnight.

Couple other points... Accelerator pump should be leather. The new blue ones are crap.
And because the 94 is not stock on the '37, you'll need to block the third hole on your manifold to protect your power valve. This is usually done with the correct gasket.

flatjack9 · 07-05-2016, 12:22 PM

A leaky power valve gasket will not show up as leakage in the throttle bores. Float might be too high. When the engine is shut off, heat from the engine will heat the fuel causing it to expand and leak out the nozzles.

37 ford firetruck · 07-05-2016, 08:36 PM

Thank you for the input. The carb is later than the engine and is properly fitted; however, the float height is definitely going to be something I check another time.

tubman · 07-05-2016, 08:58 PM

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Worn throttle shafts on 94's are not that hard to fix. I've done it a number of times. I got the oversized shafts from Mac's and the proper reamer from Amazon.com; I think it was $7.95. I reamed the bases to fit the new shafts and re-installed the throttle plates. The throttle arms on the Mac's shafts are really cheesy and held on by a screw. I grind ff the peening on the original shafts and use the original throttle levers on the Mav's shafts. Make sure you use some Loc-tite so they don't fall off.

07-05-2016, 08:34 AM	#1
37 ford firetruck Junior Member Join Date: May 2016 Posts: 9	Holley 94 model 59 I am using this carb on a stock 1937 flathead 85 horse. Rebuilt the carb and replaced all gaskets, power value (7.5), new holley jets. (.51), and accelerator pump. The carb performs well but leaks into the intake when the engine is shut off...fills the intake above the throttle butterfly and leaks out of the throttle shaft. I suspect power valve is leaking. Other thoughts would be appreciated.

07-05-2016, 12:06 PM	#2
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 6,646	Re: Holley 94 model 59 Power valve mating surface is different on new valves. You must machine the surface flat to match the carb. Insure that the gasket is sealing by filling the bowl with fuel and setting the carb on a paper towel/table overnight. Couple other points... Accelerator pump should be leather. The new blue ones are crap. And because the 94 is not stock on the '37, you'll need to block the third hole on your manifold to protect your power valve. This is usually done with the correct gasket. __________________ Alan

07-05-2016, 12:22 PM	#3
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,527	Re: Holley 94 model 59 A leaky power valve gasket will not show up as leakage in the throttle bores. Float might be too high. When the engine is shut off, heat from the engine will heat the fuel causing it to expand and leak out the nozzles.

07-05-2016, 08:36 PM	#4
37 ford firetruck Junior Member Join Date: May 2016 Posts: 9	Re: Holley 94 model 59 Thank you for the input. The carb is later than the engine and is properly fitted; however, the float height is definitely going to be something I check another time.

07-05-2016, 08:58 PM	#5
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,319	Re: Holley 94 model 59 Sponsored Links (Register now to hide all advertisements) Worn throttle shafts on 94's are not that hard to fix. I've done it a number of times. I got the oversized shafts from Mac's and the proper reamer from Amazon.com; I think it was $7.95. I reamed the bases to fit the new shafts and re-installed the throttle plates. The throttle arms on the Mac's shafts are really cheesy and held on by a screw. I grind ff the peening on the original shafts and use the original throttle levers on the Mav's shafts. Make sure you use some Loc-tite so they don't fall off.