hello

got a lincoln mk4 1974 with a rebuild 460, c8 heads, crane cam, holley carb etc
when it`s on temp. it runs great, but when it`s cold it like he isn`t running on 8 or so. when i give fast full throttle (or how do you call it) it gives backfire`s. but when hot it runs great, no problem at all.

hope you can help me, greets from holland.

 

First of all, welcome to the good ole USA, come visit us some time.

Now, it sounds like you have a choke problem, I would bet you have an electric choke. If you do you need to get it adjusted. I will not even try to explain that one, I only run manual chokes, because a good tuned Holley don't need a choke very often. If it is a choke problem you are washing your rings with unburt gas and killing your oils viscosity. Also if your Holley don't have power valve blow out protection, you may have blown the power valve with the backfire issue.

Your C8VE heads are closed chamber heads that produce higher compression. If you have stock style pistons you might be able to run ok on high octain pump gas, but if you have flat top pistons you will have to much compression to run pump fuel. (what you buy at your local station)

Be sure you have your timming set right before you do anything, this could cause a major problem to.


Good luck.
David

 

First you need to make sure the choke heater is working, if it is electric. Need 12 volts to the wire to the black cover on the passenger side of the engine on the carb when the engine is runnig. Both the manifold heated and the electric chokes adjust the same. Engine cold and not running, loosen the 3 screws holding the black round cover so you can turn it. Now throttle to wide open the get off it. Now turn the black cover until the choke valve in the top of the air horn is just closed. Tighten the screws and start and run and make sure the valve opens. About the only thing that goes wrong with the manifold heated chokes is the tube from the manifold to the choke assembly rusts out, making the choke real slow to open.

 

hello

thanks for the replies, and i`m sure i`m gonna visit the usa some time, and i`m sure i`m gonna like it. i am sure that my timing is set right. my pistons are speed pro hypereutectic pistons h535p, they are flat tops but they have a compression distance of 1.752, that wil give 185 psi. here in holland we have 98 ron octane fuel that`s a higher octane then in the usa. (correct me if i`m wrong) so that wouldn`t be an issue to. so i think the choke is a good one. i will be check this one out.

thanks again greets from holland

 

mine does the same thing, i think its cause it lacks a hot air tube like the stock breather had at one time. in the cold the fuel doesnt atomize as well and it doesnt get metered correctly through the idle circuit causing it to load up and stumble. after about 2-3 miles mine runs great. i plan on rigging up a tube off the header. look at lxmans gallery of his 77, it has what im talking about.