Vannin' Home Forums Chevy Performance (GM) Building high MPG Motor for a 93 Vhevy Van

the TBI one is vaccum controlled.. there;s a port in the TBI casting that feeds it direct manifold vaccum.. and remember, there's the links here that show you how to make your regulator adjustable.. same as the aftermarkets..

OK I missed that..of course it is internal...

Rich

Well after hours of carefull research I found two possable great cams, GM Factory only to learn thay are no longer for sale...

Any one know where I can get cam number 10066049 or 14093643

The first one is from a 88/89 Camaro and the second one is called a L98 Corvette and IROCK Camaro..

have you looked into what they call the LT4 hotcam? the profile is available in other than LT1 cam format so you can get the profile on cams for regular GM blocks. Also.. have you given any thought to the engine simulator programs? Desktop Dyno has proven time and again to be incredibly accurate.. Hotrod magazine says to deduct about 5% on the horsepower ratings, but otherwise nearly spot on.. the last one i had, had EVERY cam profile you could find,. listed by manufacturer and model numbers.. I built my last race car motor in Desktop Dyno and it gave me 428hp and 397ftlbs torque.. timeslips and car weight confirmed according to the HP calculators I was at 425 hp and 390 torque. that was putting some rather bizzar combos in the computer. have to look and see if i have my old copy layin around.

After much talk on these boards and with engine and cam makers…

I find there is no magic motor I can build, in fact I already have a motor with the peanut cam, my stock van motor has the same power and torque as the caddy model did.

OUCH…

It would be a slight improvement as in a fresh built motor but no real improvement.

OK I am giving a 383 very hard look.

I still want a mild cam, I still want a low RPM Motor, but a stroked 350 will give me more torque and HP even keeping things mild.

So if I run a stock to a TPI 350 Cam will things work? Can I stay with the 350 injectors as I am NOT building a hot rod…will a slight tune to the ecm cover the change?

I am hoping the 383 will not get worst MPG VS a 350 built the same way…

I am hoping a 383 due to its bigger torque will in fact get better MPG pulling a Van.

And combos do I want?

And what do I not want?

Thanks guys.

Rich

I put 302 heads on my 351 ford saved gas and whent like stink

I'm tellin ya.. a 350 with 305 heads, will make a torque monster.. if you're just towing, then this is the way to go.. you'll likely never see the high side of 4500rpms anyways in your normal driving, so... a 383 is going to suck more fuel.. the more cubes of air you use, the more fuel you need to back it up.. You can put 1.6:1 rockers on the exhaust to help the flow outward as well as some headers.. If i had to build another motor JUST for towing and mileage, that's what it would be.. unless you're goin racing, a 383 is a bit overkill. you will for sure need a different cam to utilize the added cubes.

I hear you but even engine builder I know say that is totaly crazy, and will not work, a) because it will need Jet Fuel to run with the compression ratios, and the chamber is not alined with the bore and it hardly takes any maching to hit water...

And with my swirl port heads they are all ready smaller...

Rich

Your engine builder is insane.. the bore centers are exactly the same.. and if you have stock pistons, the compression is fine.. as i stated above. This has been done countless times, both superchevy and hot rod mag did write ups on it and all the mods to the heads including the chambers. no offense, but your engine builder is a quack.. the chambers are perfectly aligned with the bores.. only smaller.. and all you have to do is round off the chamber edges.. you're not taking large sections of metal out.. just rounding them off. wouldn't mind conversing with your engine builder. You should see some of the things the pro-mod race car guys do with 305 heads... all the small block chevy stuff is the same.. only the bores are smaller.. nothing is shifted.. it;s all basicly the same casts.. same blueprint..