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Re: Megasquirt II ---> First Step in Fuel Economy Build
72chevyK10 sorry.
it was a major surprise to me, 049 heads, flat top pistons stock cam .460/.480 from memory. Performer intake, hooker headers xpipe, front half exh twin 3" rear twin 2.5"- did this witb broken foot so didnt end up finishing exh. 33"tyres 3.73 diff. Had vacuum feed water inj tho that didnt seem to affect mpg but ran intake very cool. A/F meter wouldnt read past 16:1, lean out cruise portion only until drivability issue than backed up one step. Part throttle is 13-14:1 and wot is too rich at 11:1. When I fitted headers cruise ran at 12:1 so I am WAY off the chart with current rods and jets. I didnt mean to imply im a tuning master. Ive since swapped head after valve seat went(old motor, pistons were still coated in carbon so not too lean). Even under part load keep high vacuum.
Now it is 7-7.5:1comp no 3 cyl is 30+lb lower on comp test- like this before. Mow avg 16 mpg aus think 13us best ive gotten latly is 18aus 15us. Down on power alot. Still get 13-14us grossing 11-12000lb. Building a new short block shortly for it.
I may have just fluked it but ill try for 20-25mpg with new eng and 3.42 diff
Also, hei initial 18* total 36-38. Cant remember, check later but think it was limited to 20* vac adv
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