engine building advice

[crm318]

here in the next few months i will be building a 350 that will be cruising the country. it will be going into a chevy van. i need some advice on building a very efficient motor. im thinking of a 350 with 882 heads, factory iron intake, new quadrajet, factory cam (or any cam that could get better mpg/power), HEI, open element air filter, and hoping for headers and chrome sidepipes. what do you guys think? is there a better cam other than factory (.390/.410) that could get better mpg? are there any better heads to go with for mpg? im going for fuel efficient only.

[cooters]

rv cam, vortec heads, and a edelbrock performer intake. Do not run an open element air cleaner, find a good one from a truck and vent it from the front.

[prostreet1967]

get some 87 up heads and tbi setup off a pickup good gas mileage and decent performance for a daily driver. o by the way don't use roloc disc for cleaning mating surfaces on engine debris from the disc will tear up the bearings

[RACINJASON22]

I aggree with cooters, making alittle more power over some of the stock pieces will actually be more pocket freindly in the end. example- parts he listed. As long as you don't go crazy. there are pluses and minuses to the open element air cleaner. I think what cooters (correct me if I'm wrong) is trying to say is tha on a van there's alot of trapped hot air more so than on a pick-up and designing a good cold air intake would be a very good choice.

[TheSasquach]

If it were me, I'd go to Randys ring and pinion ( http://www.ringpinion.com/Calc_RPM.aspx ), and use there calculators to figure what RPM the engine will be operating in the majority of the time and find a cam, intake, and head package that makes peak HP at that RPM. that is where you will get the best MPG from. and definatly make good big cold air intake system to a duel snorkel air cleaner. David

BTW Im speaking from experence i built a .060 over 383 big block Mopar in a 3900# '69 Plymouth Satalite that made extremely nice HP and insane torque and got 23MPG from it.

[jimfulco]

Small-chamber heads with good swirl, D-cup pistons, itty bitty cam, something like a TBI 350.

[PanelDeland]

I agree with the engine stuff cooters suggested.Then go to an OD tranny or a gear vendors unit.Tire hieght will make a difference also.Unfortunately you will probably not get very good milage pushing a "wall" down the road.If you are really looking to get a van as efficient as possible you might also consider lowering the suspension a bit to lower wind resistance,maybe a front air dam,use narrow tires to reduce rolling resistance.Unless it's a passenger van a wall behind the seats will enable you to cool it on a lower AC setting.Maybe look into underdrive pulleys to free up some horsepower.
You might also look into whether the extra torque from a stroker might give you a better chance of meeting your goal since you are looking at using it in a heavyvehicle that is only slightly more aerodynamic than a "brick".Volumetric Efficiency is the key to power and making the engine a better "air pump" in the rpm range you need is the key.

[AR15DEFENSE]

Originally Posted by prostreet1967

get some 87 up heads and tbi setup off a pickup good gas mileage and decent performance for a daily driver. o by the way don't use roloc disc for cleaning mating surfaces on engine debris from the disc will tear up the bearings

^ I agree.. with all of it, gm had a TSB on the roloc discs a few years back

go with TBI, will take more time to setup, but in the end you will have much better fuel mileage as well as being easier to diagnose

[crm318]

well this is actually a swb chevy sport van. the engine compartment on this thing is like an air funnel. i wont have enough money to do a whole lot. the route i think im going to have to take is having a th350 with a 2.73-3.08 gearing.

[AR15DEFENSE]

Originally Posted by PanelDeland

go to an OD tranny or a gear vendors unit.Tire hieght will make a difference also. Unfortunately you will probably not get very good milage pushing a "wall" down the road.

I agree with this too. low gears are good, skinny tires are good, but I think a van shaped like a door wedge would be best.

[GREASEMONKEY72]

i agree with what all as been said, any pics of the van by chance? and if it has dual head lights you can make a nice intake system using the inside light holes

[crm318]

[martinkh]

Lots of dueling advice!!
If you keep 350cid, the cast vortec heads are a good deal. Use a true dual plane intake and a 600cfm quadrajet. I like crane cam's MPG series carb. MPG/RV type cams will float the valves at around 5,500 rpm, so you don,t need any intake that says it makes power after that.

Otherwise, k&n filters are pretty good. Regular HEI is just fine, but maybe the money you save by not retrofitting TBI could go to something like a jacobs ignition, but then you add an electronic failure mode to your engine (but they are supposed to be reliable). Or the 700r4. A well tuned q-jet is wonderful, and the vacuum secondaries make it very efficient, not much less than TBI. The difference in price would well put a 700r4 under your rig, even if you wait a few months to accumulate the cash for it.

[crm318]

well this has all been good advice. i appreciate it alot. i will do alot of research this weekend.