[92GA]

Got some questions on timing issues. Swapped to E85 on my sons bird with a #16 headed 406. 12.5/1 comp. How much timimg you guys running on E85 & iron heads. Threw the carb I had built for my 406 sbc on the Pontiac last weekend. Was picking up 30/35 degrees in the 1/8. So I know it was plenty lean. Fattened it up some. The car ran the best times ever and we went from a 28" tire to a 32" tire. Was running about 41 degrees on my alum headed sb with the E85. Having a heck of a time trying to get this thing to idle, wants to die when pulled in gear. Didn't do that on gas, but never idled very good because of the low initial timing. May go try and add some timing to get it to idle better.

[TA454]

I am running 42 deg on my E85 496 w/ steel heads

[92GA]

Originally Posted by TA454

I am running 42 deg on my E85 496 w/ steel heads

Thanks. I ended up increasing the initial timing to 14 degrees and got the engine happy at idle, and am able to drop it in gear now. Sounds better on the E85 than it did on gas, but ended up with about 41 degrees total. Guess I'll try it Sunday and see if it likes it. Only ran 35 degrees on gas. Thinking about making some nylon stops to limit the total to see where the engine works the best. Then weld it up.

[TA454]

I used to only run 36 deg @3500 RPM on gas also.when I ordered my carb from Pro Systems they reccommended the 42 deg setting. I have 22 deg mechanical in the distributor. which in theory gives me 20 at start up. with those settings once the engine is warm i can idle @ 850 RPM in gear.

[tininjun67]

not a good comparison, but I run 40 degrees in a 400 with e85 also, but it has horribly low compression with a set of 4x's on it. probably less than 8:1. lots of initial will help with the idle. do like you were thinking and limit the mech advance some. this is a driver though.

[92GA]

Just got back from the track a little while ago. Going from 35 degrees to 41 degrees slowed the car .07. Looks like I'll have to make some spacers for the dist.

[92GA]

When to the track yesterday, hotter than ell. Made some teflon spacers for the dist. 17 initial 34 total. The car picked up 1.5 mph over the best on gas. Still picking up more heat than I exspected on E85, don't seem much better than when we were on gas. The car does et and mph better than gas though.

[J.C.you]

it may run better on less than 34 total timing.

[Torment]

I like to see about 10-15deg increase from the line to the stripe. I also look for about 50% burn of the plating off the the face of the plug - I use NGK plugs that allow for this read. I've leaned it out more and haven't really seen any appreciable gain from there.

[92GA]

Originally Posted by J.C.you

it may run better on less than 34 total timing.

It ran best on gas at 35, timing line on the strap is only about 1/2 way to the bend. It used to be a little farther than that on gas. I will try a little less next time out now that I've got it running better.

[92GA]

Originally Posted by Torment

I like to see about 10-15deg increase from the line to the stripe. I also look for about 50% burn of the plating off the the face of the plug - I use NGK plugs that allow for this read. I've leaned it out more and haven't really seen any appreciable gain from there.

Boy, wish this thing would only pick up 10/15. That's about what I was getting on my sbc with this carb. We're getting 20 on the run but keeps climbing even on the return road. Same thing it did on gas. Starting to think something else is the problem. Only running a moroso pump drive, that may be the problem. Was thinking head gasket at one time, but don't lose any water, and no bubbles in the raditor, no water in the oil.

[Torment]

Those Moroso drive kits are low rpm marginal cooling for sure. I'd put a good electric like Meziere or CSR on it before I spent too much time chasing heat issues. Good luck!