This sounds similar to a problem Rick [Rick55] was having with needing some juice or it wasn't running right off idle, pretty sure he has the same cam with a 465 carb. He finally sorted the problem all it was for him was upping the jet sizes considerably and now all runs sweet so he said. Maybe Rick will see this an confirm.



"Came too close to dying to stop living now!"

Thanks. I'll have a look at the alignment this weekend, for now the car is outdoors and its raining....as ever in this wet country 😀

When composition head gaskets are used, which are included in most gasket sets, rather than original style shim gaskets, you have to remove about .030" from the heads and / or block just to get things back where they were.  More or less than that and you do need to pay attention to the alignment.

I'm sure you'll find the problem.  Even if you had swapped to another engine, no other engine is immune to these types of problems and you could still be fighting the exact same thing.


Lawrenceville, GA

Thanks , I know that the heads and the block were milled, problem is I don't know by how much. I'm guessing this might be my problem. I did a smoke test on the engine but couldn't see any leaks, however i did have an intake leak on first start up after the rebuild and had to replace the gasket. I think this needs further investigation. If I take the manifold off I think i would be able to see where it's sitting by the indents left on the gasket. It's an original Ford 4 barrel intake.

Mike, I had the same sort of frustrations more than once. Just some more thoughts, as I think you've got either a vacuum leak or a bad carb. Funny to have two of them bad.

What manifold are you using. There's been some conversations about some manifold/carb combinations not sealing well from the base plate to the manifold. I've not run any stock manifolds in years and I don't remember the particulars, maybe someone will chime in.

Also, did you deck the block and/or mill the heads? If so, did you dry fit the intake and check the head manifold surfaces were parallel? In some cases you have to mill the manifold also. I think Ted's site has something that addresses that.

Years ago I ran an RPM300 Isky, which I think was a little more cam. It liked 900 or so rpm at idle, maybe a bit more when it had the fordo in it. But it was definitely a street cam.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Thanks chaps, seems it's a characteristic of this cam. I'll get it back running and see what i can do with the carb. Annoying when it ran sweet before i rebuilt it even though i had 2 blown head gaskets, one cracked head and a cracked block 80 thou overbored. I wish I'd dumped it now and put another motor in it.

Looks like everyone's engine experiences different results. My 292 with the E4 idles nicely at 625 RPM, this is a standard trans car, just a slight rumble, you can hardly tell its got a cam which is what I wanted. I'm using a small rejetted 390cfm Holley. 12 degrees initial timing with a 34 degree mechanical advance distributor. Best I can get is 14 HG at idle..

I have the Isky E4 in a 272 engine with the stock compression ratio and have had a variety of carbs on it over the last 145,000 miles since it was rebuilt.  The Carter/Edelbrock carbs were the most troublesome in getting them dialed in right.  Holley carbs ran well but fuel mileage was always a bit less than desired when getting the drivability just right.  Put a lot of miles on the engine with a Road Demon Jr. 525 carb that ran quite well with fuel mileage in the 17-19 range but when it needed a kit after 13 years of driving, I simply installed a new Summit 500 cfm carb which I have not had to tinker with at all.
 
The vacuum advance is hooked up to the ported vacuum port at the carb while the intial timing is set at 12-14° with the vacuum advance unhooked.  At idle, there is no vacuum advance signal at the distributor and idle and the timing does not change when the vacuum advance hose is hooked up.  That simply means the throttle blades are in the correct position at idle.  Haven’t done a legitimate fuel mileage check with this particular Summit carb but it’s good.  While the E4 camshaft does have some rumble to it, the idle is smooth at 800 rpms and the idle mixture screws are totally adjustable.

Lorena, Texas (South of Waco)

I tried all sorts with the Holley Chris, gave up and bought a new Edelbrock. In retrospect I should have persevered with Holley as I don't like this Edelbrock one bit. I'm guessing I'll have to live with it now, I'm sick of messing about trying g to get it to idle nice.

Hi Mike,i 've the same cam in my truck,forget a smooth idle!I have the same problem with idle mixture screws,things got better by plugging vacuum advance to a manifold source and opening the secondaries a bit on my Holley at idle,i don't know if you can do that with an Edelbrock.With this set up i'm having 16-17 HG of vacuum at 800 RPM.