'65 L-79

[Jeremy Hedges]

I have a '65 L-79 that has been completely rebuilt, the original carb was rebuilt to specs by holley. I just have got this car where I can drive it and at high rpm's (over 4000, it has a 4:11) it start to bog down, it almost seems like it is loading up, it just looses power. I checked the carb and both the front and back bowl floats are adjusted according to the manual (right at the bottom of the sight screw). What could be the problem?

Jeremy Hedges
#31711

[Duke W.]

Re: '65 L-79

It could be ignition related. Bring the revs up to 6000 no load with a dwell meter attached. If the dwell angle varies more than two degrees the distributor needs to be overhauled because the breaker plate is wobbly and/or loose bushings and too much end play. Also, you should use the 28-32 oz. breaker arm tension points.

If it passes the above test - less than two degrees dwell variation at 6000 - then it could be the carb. Have you checked that the secondary throttles are opening properly?

Duke

[Clem Z.]

Re: '65 L-79

make sure the heat riser valve is not on upside down or stuck closed. i have seen both and the engines will bog down at full throttle.

[Roger Legge]

Re: '65 L-79

Possibly a weak fuel pump? Fuel filter needs replaced?

Roger

[Rich G.]

Re: '65 L-79

My 66 L79 ( 3:70 rear) driver was like that. Finally got around to fixing a broken vacuum advance and replaced points with HEI (probably not necessary) and timed it yesterday and the results are like night and day. Used to stop "pulling" around 4500. Now it revs to redline under load without a hitch. I drove it all day today just because it's running so good!

Rich

[Rich G.]

Re: '65 L-79 Addendum

Forgot to mention that I also found the vacuum advance line connected to the wrong place. (Ported vs. Unported) There's a thread going on about this under the topic of "Total Advance"

Rich

[Edward H.]

Re: '65 L-79

as silly as this sounds I had an almost identical probem with my 69 non matching BB which has some engine mods. After 2 yrs and replacing fuel filters, fuel pumps,coils, distributors,countless jets, power valves, and nozzles. It was as simple as the air filter. I stumbled across the K&N website and they have a formula for calculating air flow, which I did and found out that the replacement paper filter wouldn't flow enough. I took the air filter off and it ran up to 5500 with out a hitch, before it would start to bog down around 3500. I have since bought a filter that exceeds the requied cfm and it runs like a charm. good luck