high egt

Posted By: 67valiant

high egt - 06/09/14 08:46 PM

ok im running a 406 with a 570 comp cam 850 speed demon 11.1 comp indy heads 360-1 temps were 1400f with egt in #3 and #8 jetting the front up from 86 to 90 temp now 1250 -1300 on #3 jetted back up from 92 to 98 still have 1400 on #8 was at 33 degree went to 35 still about the same is it the gas im using ? I run av 100 the guy use to run 92 mix with 108 50/50 with a 830 holley any ideas ?

Posted By: Airwoofer

Re: high egt - 06/09/14 08:55 PM

Is the #8 header tube crushed?

Posted By: 67valiant

Re: high egt - 06/09/14 09:04 PM

nope new motor last year no probs at all

Posted By: MR_P_BODY

Re: high egt - 06/09/14 09:24 PM

Very well could be the fuel... I've never tested with
AV gas so I dont know for fact.. put some race fuel
in it to see if it is the fuel... I normally run at
1250 + 50
EDIT
Also if you have tested for best MPH you could be
adding fuel and not burning it(fat in the cyl) and
its burning in the tubes... for a quick check add
2 more jet sizes and see if your EGT goes up higher

Posted By: v cummins

Re: high egt - 06/09/14 09:33 PM

Check out a four pattern cam with # 8 exhaust opening two degrees earlier and intake closings two two degrees later. can do all long runners but just doing # 8 will work fine. Do you have a single plane intake ?

Posted By: 67valiant

Re: high egt - 06/09/14 10:43 PM

sounds good mr p I did look at the plugs it they did look lean and when I jetted up rear the egt stayed the same 1400 1425 and ya its single plain idy intake

Posted By: Cab_Burge

Re: high egt - 06/09/14 11:37 PM

Are you using all eight EGTs or moving them araound? If all eight, it may be time to start working on the intake manifold to cure the fuel distribution problems

Posted By: MR_P_BODY

Re: high egt - 06/10/14 12:21 AM

Quote:

Are you using all eight EGTs or moving them araound? If all eight, it may be time to start working on the intake manifold to cure the fuel distribution problems

I'm thinking he has 2 and thats it... I use the egts
on all of the tubes at 1" to balance the intake

Posted By: Thumperdart

Re: high egt - 06/10/14 01:44 AM

Quote:

Quote:

Are you using all eight EGTs or moving them araound? If all eight, it may be time to start working on the intake manifold to cure the fuel distribution problems

I'm thinking he has 2 and thats it... I use the egts
on all of the tubes at 1" to balance the intake

THIS................At Pettis when I worked in the dyno room settin everything up to be run in we used all 8 and Jason said it was the best way he knew to do it and I didn`t question him either way.

Posted By: TRENDZ

Re: high egt - 06/10/14 02:34 AM

Late ignition will cause high egts without engine melt down.

Posted By: 67valiant

Re: high egt - 06/14/14 01:14 AM

ya just 2 egt probes one on #3 and #8 ya so I was thinking to bump timing up ? to 36-38 it was on dyno with 830 annular with no probs