Cam comparison: hydr. FT vs hydr. Roller

[Krooser]

The fact that this is an LPG engine it will benefit from less over lap if economy is the goal thus building more low end. I have had many fleet tow trucks from our wrecking yard that were LPG fueled and I tried everything with in reason to get the best power and economy from them. Both sm amd bb engines and they all enjoyed less over lap. Any sign of lumpy idle and the fuel mileage suffered badly while they seemed to make better power and different RPM's but the bottom line was they were commercial trucks and while they ran 10-14 hrs/day and hard work towing It turned out to be a better option to just go more inches which gave the best of both worlds.
All our trucks had BBC or BBF 385 engines in them and while the cost of fuel remained under .020 cents/liter for many years back in the 80's it slowly when through the roof to the point where gasoline was cheaper to buy and run based on the fuel demands of the trucks I tried for years to get then right and better on LPG but the fuel was getting worse here and would not take the higher comp. it did 10 yrs prior then came the cost per trip thing.

While engine wear was much less on LPG fuel and oil looked like it was just changed I just don't see it being better economy with more overlap. Some of the best MPG we got was done with custom cams made with less then a factory stock cam had. They would run out of power at about 4500 rpm but that was the point of the exercise.

Better fuel MPG and less wear and tear.

That's mostly the reason I went with the XE256 cam when I put this engine together. It appeared to be the most logical cam to go with.
To be honest, the current cam works very nice as it is; Stock idle, very good vacuum, pulls good in mid/upper range...
The car currently makes 234hp on the chassisdyno.
It's just that... I want more.

The mileage however still sucks badly. I can't get it over 12mpg. 15mpg if I baby it on the highway.
Partly I think this is because of the heavy (Dodge truck) transmission (A518/46RH) which has OD only, and a 'late 60s 727 stock stall convertor from a fullsize Chrysler.
The transmission will be changed for a lighter (A500/42RH) version in time with OD+Lockup, and matching smaller diameter lockup stall convertor. First gear on these transmissions is a bit deeper than the 46RH. I really expect this to have some effect on mileage.
So because is bad as it is, I decided to have some more fun out of this engine, while keeping this an every day driver.

A head change is planned too. I have a pair of 65cc SpeedMaster alum. heads waiting.
I will mill them to similar cc as the current castiron heads and give them a nice multi-angle valvejob and hopefully gain some low lift flow as well.

Looked at your website....nice to see you're having fun with your cars.

[BigBlockMopar]

Thanks. Always too much projects. Never enough time.
And always the urge to improve things and not leave anything alone.