Turbo/propane/intercooler 240 ci in 1965 F100.

[WhitewallWill]

Hi All, I am accumulating parts for a 240ci currently running on propane and while reviewing parts I have vs. parts I need, my question concerns the need for an intercooler. My first crack at the turbo install will be under the bed behind the rear end. Logic is because I don't have to mess with anything under the hood on the first round and I can drive it while building it. I won't run an intercooler in this scenario as the pipe length should suffice. Once I move the turbo under the hood, do I need to run an intercooler given the propane fuel system is cold cold? The relative costs have me considering options. Scavenger oil pump, at least a quiet one, isn't cheap but, no intercooler in this case. Ultimate plan is EFI exhaust manifolds to single 3" exhaust with under hood turbo location. I can see the possibility of turbo in the rear running good enough that it may stall back there and never make it under the hood. I kind of like the stealthy nature of out back. Oh the options we must consider!

 

[pmuller9]

Hi Will
The turbocharger outlet air temperature at 10 psi of boost is about 200 degrees F when the ambient temp is 75 degrees F.
For under the hood, If the propane has a cooling affect as it enters the airstream, an intercooler will probably not help much more.
You certainly won't need an intercooler for a rear mount turbocharger.

If you use a high quality scavenger oil pump and the turbocharger responds fast enough for the job, you might as well keep the turbo rear mount.

It may also be possible to use a power steering pump as a scavenging pump.

 

[WhitewallWill]

Hi Will
The turbocharger outlet air temperature at 10 psi of boost is about 200 degrees F when the ambient temp is 75 degrees F.
For under the hood, If the propane has a cooling affect as it enters the airstream, an intercooler will probably not help much more.
You certainly won't need an intercooler for a rear mount turbocharger.

If you use a high quality scavenger oil pump and the turbocharger responds fast enough for the job, you might as well keep the turbo rear mount.

It may also be possible to use a power steering pump as a scavenging pump.

That's great info, thanks. You are probably the first person that didn't try talking me out of putting the turbo in the back. A power steering pump for scavenging is novel and a heck of a lot cheaper than a purpose pump. I take it you are thinking an electric version?
One more question is about running a muffler. I've read conflicting info about the need to have a muffler for a rear turbo as the turbo itself does some noise cancelling. I have a 3" inlet/outlet Flowmaster Super 40 and I will be fabbing the full setup so what do you think - Muffler or no muffler?
By the way, I reached out to Schneider Cams with your recommendation. Jerry confirmed your suggestion, just waiting for a lead time from him. Would you recommend an upgraded single valve spring?
Thanks again for all your help.

 

[pmuller9]

I was thinking of the standard belt driven power steering pump.
Mount it low enough so the pump's inlet was even or below the turbochargers oil outlet fitting
I know a good electric scavenging oil pump is around $400 but it still has a limited life span.
I have better faith in a mechanical pump.

I would try it first without a muffler and if you find it too loud then you can add a muffler.
This is one of those things you can do in stages.

A single coil upgraded spring will work.
A turbocharged engine needs more spring pressure on the intake valve seat in order to close the valves against the manifold pressure.

Are you staying with the stock valve size in the 240 head?

 

[WhitewallWill]

Good advise. Will look into the power steering pump idea as I might have an extra one. I'll plumb it through the fuel pump block off plate. Everything I've read on the rear turbo points to oil scavenging as the achilles heel of that system so an electric may well be good to avoid.

I got a quote for a Promaxx 4-5 months ago but, thinking I'd prefer to P&P the stock head first especially if I have the 240. Do you think there is much of a benefit to changing up the head especially if I get roller rockers and upsize the valves?

 

[pmuller9]

If you change to a head that has a larger combustion chamber you will decrease the compression ratio.
The stock head has around a 68cc chamber, The Promaxx CNC ported head has a 73cc chamber.

I would do a moderate valve size increase because the 240 head chambers would have too much shrouding for a 1.94" intake valve.
Consider the Chevy 1.84" intake and the 1.60" exhaust valves.

 

[WhitewallWill]

I think I follow you. So if you tried to unshroud for a 1.94 intake valve you would inadvertantly upsize the combustion chamber and bring down the compression?

 

[pmuller9]

I think I follow you. So if you tried to unshroud for a 1.94 intake valve you would inadvertantly upsize the combustion chamber and bring down the compression?

That is correct.

 

[WhitewallWill]

Excellent thanks.

 

[jgregg13]

I got a quote for a Promaxx 4-5 months ago but, thinking I'd prefer to P&P the stock head first especially if I have the 240. Do you think there is much of a benefit to changing up the head especially if I get roller rockers and upsize the valves?

Just my opinion for what it's worth (probably not much). Boost makes up for breathing limitations. If you need more power, just add a couple more PSI of boost. Mine is yet to run but I'm running stock head and valves with the stock cam. I just unshrouded the valves and cleaned up and deburred (rounded edges) the chambers to lower compression a bit and reduce hot spots. Unless you're building a race engine, I don't think you need a bunch of other options. I'm also using ARP head studs and rod bolts, metal cam gears and a high volume oil pump.

 

[WhitewallWill]

Just my opinion for what it's worth (probably not much). Boost makes up for breathing limitations. If you need more power, just add a couple more PSI of boost. Mine is yet to run but I'm running stock head and valves with the stock cam. I just unshrouded the valves and cleaned up and deburred (rounded edges) the chambers to lower compression a bit and reduce hot spots. Unless you're building a race engine, I don't think you need a bunch of other options. I'm also using ARP head studs and rod bolts, metal cam gears and a high volume oil pump.

Hi John,
I have a picture in my mind of a bat house on a pole. If it is yours then we have definitely talked. Anyway, opinions are the reason I'm on this forum so I appreciate yours. I'm going to run my existing head and take pmuller9's advise on the 1.84 intake, 1.6 exhaust valve, roller rockers and P&P the head. I may want to take the truck to the strip, something I've never done before. It's a father & sons project so thought I would get a little more out of the engine and maybe push the boundary a bit. I will do the ARP studs and metal timing gear. Dialing up the boost is a possibility. I have told myself 6-8 psi but, 10 is a possibility if we build it strong enough.

I'll check out Mabel on your site. 'Clementine' is our girl's name.
Will

 

[jgregg13]

Yes, it's the bat house, 'cause we're a bit batty here. If you're in the area, drop in. Mabel Goodwin was my grandmother"s best friend who had a '48 Chev business coupe and my brother and I when we were very young would ride standing in the back holding onto the rope across the back of the seat (no back seat).

 

[WhitewallWill]

Ha ha. Priceless. Story I heard a long time ago was about tearing down kid's wooden playground structures because they were dangerous. The backstory was about picking the swing with the nail sticking out of the seat because you used the nail to hang on to. We will most certainly drop by if we are in the area with suitable notice of course. Went through your thread on Mabel and I remeber seeingit in t.

That's what a thought looks like when the phone rings and off you go. I saw your car many times while walking the dog just never ran into you to chat about it I guess. You would have been peppered with questions had I caught you.

 

[trkkr]

here is some good information https://www.ford-trucks.com/forums/1393610-79-f-100-turbo-300-6-sleeper.html