Crate engine swap advise please?

[73 C10]

You still running the stretched 8# springs? Do your step-up pistons move freely?

Good question. They do with the engine off. I press them to make sure before I close the top. I haven't checked with the engine running and the top open with the screws and caps off recently. I will though.

Oh yeah. 8". I just check the stretch. They're both 1.75".

 

[rich weyand]

Good question. They do with the engine off. I press them to make sure before I close the top. I haven't checked with the engine running and the top open with the screws and caps off recently. I will though.

Oh yeah. 8". I just check the stretch. They're both 1.75".

I just check mine with the engine off.

Yeah, somehow you are getting extra gas in there on power.

What does your idle mixture read at?

 

[73 C10]

I just check mine with the engine off.

Yeah, somehow you are getting extra gas in there on power.

What does your idle mixture read at?

I've got idle at 13.

 

[73 C10]

I think he has all of them on these two pages:
http://www.carburetor-parts.com/Carter-AFB-Gaskets_c_575.html
http://www.carburetor-parts.com/Carter-AFB-Gaskets_c_575-2.html

I'm not sure if it these

http://www.carburetor-parts.com/Carter-AFB-Venturi-Cluster-Gasket_p_1402.html

or these

http://www.carburetor-parts.com/Carter-AFB-Venturi-Cluster-Gasket_p_1431.html

I think they are the second link. I'll take it apart and look before I order for sure.

Thanks for the link.

 

[73 C10]

I just check mine with the engine off.

Yeah, somehow you are getting extra gas in there on power.

What does your idle mixture read at?

I have noticed what you are talking about though. When I first stretched the spring a bit I don't think I stretched one quite straight and it would possibly have side loaded the slider and put it in a bit of a jam not alowing it to move freely. I think I corrected it though.

I do think the springs should possibly be even stiffer to get the transition timing a bit sooner.

I want to get the gaskets first.

 

[rich weyand]

Yeah, 13 at idle is good. The reason to run the idle that rich is that the mixture at such slow stack velocities doesn't get a lot of turbulence, so it can be uneven. If you try to set the idle mix at 14.7:1, some cylinders will occasionally see a mixture above 17:1, and you will have an occasional miss at idle.

I stretched my springs to have 1/4" longer at-rest length, and my engine draws the same idle vacuum as yours, so I would think you are pretty close with those.

 

[Joe383]

I have my idle around 13.5 I tried it leaner but it was a dog just off idle.

 

[Joe383]

Dam this post went far. I have been away for a wile. Looking back at like the bottom of page 6 though... Ya getting it tuned rite might yield the results he is after. Has to figure that out anyways as he might have the same problem with a new motor too. 24 pages is just too much for me to read over. Sounds like you guys have done a pretty good job of leading him in the right direction though.