33 Degrees timing in 406SBC on Methanol???
05-09-2008, 04:41 AM
#1
Junior Member
APPRENTICE
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Join Date: Oct 2003
Posts: 19
33 Degrees timing in 406SBC on Methanol???
Looking for some input on timing on a 406 sbc. We switched to methanol this year (750 carb with mechanical fuel pump) I think we have about 164 jet in the front and 170 jet in the rear. Our plugs show color, but there not black or anything. The people (Shafiroff) we bought the short block said that we shouldn't run anymore than 33/34 degrees of timing??? With our gas motor we ran anywhere from 38-40 degrees of timing to make it run the best. Our cam is degreed 2 degrees. We don't want to hurt the motor by running too much timing....is this possible? Some other people we talked to at the track actually said to run more timing with methanol?? Any input will help....thanks in advance. Derek
05-09-2008, 10:05 AM
#2
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RACING JUNKIE
Join Date: May 2003
Location: Coldwater, MI
Posts: 2,998
33-34 is in the ballpark of where you need to be. The plug should be a bit on the brown side and thats it. My alky stuff is always squared in jets and no powervalves also. I think you'll find the more timing you toss at it the slower it'll be.
05-09-2008, 08:19 PM
#3
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RACING JUNKIE
Join Date: Jan 2006
Location: La.
Posts: 2,890
I run 38 degrees on my 377" with a toilet bowl, but it doesn't help the top end at all. The only reason i run 38 degrees is that the car weighs 3250lbs and i need it for the 60' time, in fact the car will only run 125 and should be running about 128 so it's a trade off. Any more inches and i would also run 34 degrees, like we do on the 434" motors.
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05-10-2008, 06:34 AM
#4
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Join Date: Dec 2005
Location: Rutherfordton North Carolina
Posts: 192
The amount of timing you need is determined by the combustion chamber design. most 23 deg heads with a conventional chamber like Dart will make peak power @36 deg. vortec or other 23 deg fast burn heads like 32/33 deg 18 deg heads like 33/34 deg,SB2.2 heads like 30/31 deg. Bill
05-18-2008, 02:29 PM
#6
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Join Date: Oct 2003
Posts: 144
I have found that alcohol engines do not require alot of timing.
we run 32-34 degrees.
As for tunign on alcohol, plug color is not going to work. You need to run a plug with the gold color cad plating to see what temp your engine is at, look at the ring that supports the outer electrode. It should be discolored about 75% of the way around for best mixture.
Other than that use a EGT and at wot you should see 1100-1200 degree's
we run 32-34 degrees.
As for tunign on alcohol, plug color is not going to work. You need to run a plug with the gold color cad plating to see what temp your engine is at, look at the ring that supports the outer electrode. It should be discolored about 75% of the way around for best mixture.
Other than that use a EGT and at wot you should see 1100-1200 degree's
