This is different. De-tuning a Clevo for gas mileage...
September 29 2011 at 1:39 PM
(Login danford1) Member from IP address 188.8.131.52
Normally people come here to get info on how to make their engine more powerful and faster.
As you know, I'm a bit different to start with... I need to de-tune a Clevo for gas mileage. Please allow me to explain.
I took my 68 Mustang with my built up Clevo on the final leg of the Hot Rod Power Tour this past June. WOW, what an amazing experience. I want MORE.
I drove 568 miles and used 49.1 gallons of 93 octane pump gas. That is only 11.56 mpg. My engine is set up to do high 11's in the quarter, not to cruise along efficiently.
I decided I want to go on the complete Power Tour next summer. It is supposed to run from Detroit to Fort Worth Texas. The Detroit part is easy as I'm only 30 miles from it. Driving to and from Texas is going to require great quantities of gas.
Here is what will change for sure on my car. Out comes the 4:11 gears. In goes a 3:50 set. My trans is an AOD so overdrive and 3:50 gears will play nicely together. I already have the pig so this swap is easy and close to "free".
Out comes my 3500 stall non locking converter. In goes a stockish stall and lock-up converter.
As for the engine, I have options. First off I have two engines each set up a bit differently. I will most likely use the two to build one.
The engine currently in the car has TRW/SpeedPro pop up pistons and closed chamber iron 4V heads, Strip Dom intake. I cc'd everything and have 11.8:1 compression. It also has a solid roller cam.
My spare engine has normal dished pistons and open Chamber 4V heads and a solid flat tappet cam, Torker intake.
I also have a nice set of iron 2V heads with screw in studs and 72cc open chambers. No intake for them though.
My thought was to use my pop up piston short block and the open chamber 4V heads for about 10:1 compression. 91-93 octane should work with that.
I was also thinking of going with a mild hydro roller cam for low speed drivability and gas mileage, plus with the stock type lock-up converter it can't be to wild. Probably use the Torker intake too. I know this won't be fast, I want max gas mileage on a road trip using mostly parts i have on hand.
I WILL NOT consider using a 302 or anything else. This will be a Clevo powered vehicle...... period...
I have a few carbs to pick from but that won't be part of this engine build discussion.
The car has and will retain the Hooker Super Comp 6210 headers. I used them before with the 2V heads so I know they would work with them if I go the 2V route.
So to summarize I have two short blocks, 1 with pop-up pistons and 1 with dished pistons say 0.015" down in the holes if my memory is right.
I have iron 4v closed chamber heads, iron 4v open chamber heads (I think with the 2V valves), and a set of milled 72 cc 2V iron heads. All heads have rocker studs and guide plates.
What combo of the available parts would net me the most gas mileage for a say 2800 mile road trip?
Also include the cam specs of course The cam will be the Key ingredient here.