1965 F100 Father and sons project with 240/300 Big 6

[THE FRENCHTOWN FLYER]

Hi again WW, I just found your build thread. I usually only read the Big Six section so its gone un-noticed to me for months.
Re: the intake plenum:
FoMoCo design guidelines for dry fuel intakes called for the runners to extend into the plenum by about an inch with a bell mouth. Also the plenum should extend about an inch past the end runners for efficient filling. These are little fly-spec improvements to get to an optimum manifold but do not worry if that is not possible with your current design. The improvement would be small.
Yes, the radius could be bigger. Here is a pic of one I fabbed to give you an idea of an entry, and another my friend did using a lower EFI. What I've also done is to use a radius cutter in a router to slowly remove the material.

 

[WhitewallWill]

Hi again WW, I just found your build thread. I usually only read the Big Six section so its gone un-noticed to me for months.
Re: the intake plenum:
FoMoCo design guidelines for dry fuel intakes called for the runners to extend into the plenum by about an inch with a bell mouth. Also the plenum should extend about an inch past the end runners for efficient filling. These are little fly-spec improvements to get to an optimum manifold but do not worry if that is not possible with your current design. The improvement would be small.
Yes, the radius could be bigger. Here is a pic of one I fabbed to give you an idea of an entry, and another my friend did using a lower EFI. What I've also done is to use a radius cutter in a router to slowly remove the material.

Morning FTF, glad you found us! I see the radius size in your photos. That looks like some mad science on the individual runner design. Because the tube cross section on ours doesn't have enough width to allow for a bell all the way around, I'll radius the entry heavier along the length. Once everything is tacked together I'll work the tube entry leaving the end caps off until I'm happy with how smooth it should be. As far as the end caps are concerned, if I have the room at the firewall to cap the end as machined I'll leave an inchish of room past the runner entry. I plan on contouring the mounting plate so the end caps running past the bottom plate will look appropriate.

Checking in with any propane experts out there. Does anyone know how big the cfm should be for the propane carb to get us to 350-400 horsepower? That figure is not written in stone but, is the max power rating on our turbo. We will be sneaking up on that figure for a while. The photo attached was the intake I found a while back for inspiration. Because of the traditional look of the vehicle I was looking for a design that would match up with our theme.

 

[pmuller9]

I'm assuming this will be a blow-thru turbo system?

 

[WhitewallWill]

I'm assuming this will be a blow-thru turbo system?

Yes it will be a blow through system.

 

[Engine Fan]

Check out "Raso Enterprises" alternative fuels forum for some good info on propane and turbos.
If a well built 300 makes 300hp on gasoline and you're down 15%(worse case) because of gaseous propane, you're at 225hp.
Now take 225 horsepower times roughly 1.5 pressure ratio from your 8psi and you end up with 337hp(very oversimplified)
225 mixer/carburetor is reported to be good for max 5psi, and 425 mixer max 8psi.
While you may not get to your 350 to 400 hp goal at 8 psi, the fun factor is likely full of grins.
You have yourself a very good project there, especially with your family involved.
Doing something similar with my 67 f100. Building a 300 on propane naturally aspirated to start but turbo eventually. Using the Impco 425 mixer/carburetor on my build.

 

[bubba22349]

Or you could also run a Pair of the IMPCO Mixers Too.

 

[WhitewallWill]

Or you could also run a Pair of the IMPCO Mixers Too.

Why am I so impressed with this suggestion? Because it's nuts. I was thinking of splitting the manifold for a 2 barrel plate. And if I put 2 mixers on, would I need 2 turbos. The 425 Impco looks like the solution but, a turbo'd 300 with dual blow through carb/mixers on propane. Has anyone ever seen such a thing?

 

[bubba22349]

You should get better fuel distribution on any Inline six with two Carbs its kind of like FTF's Clifford 2 X 4V Intakes either on one of his drag cars or his street car. And the Cool Factor doesn't hurt the looks either. Twin Turbos would also work great there are some examples all ready of 300 Twin Turbo'ed gas engines. I was also planning to go this route after discussing it with pmuller9 for a full on Drag Six Race Engine build using a Ford 262 that is if I can ever locate a good Short block and head.

 

[Engine Fan]

Why am I so impressed with this suggestion? Because it's nuts. I was thinking of splitting the manifold for a 2 barrel plate. And if I put 2 mixers on, would I need 2 turbos. The 425 Impco looks like the solution but, a turbo'd 300 with dual blow through carb/mixers on propane. Has anyone ever seen such a thing?

Jay storer
Looks like he used 2 200 mixers/ carburetors

 

[bubba22349]

LOL yes! So there you go its all ready been done.

 

[Engine Fan]

The Impco 200 is definitely boost friendly compared to some of the other mixers by design. No hat requiredused throttlebody from 4 cylinder Dodge Journey on Impco 200

 

[WhitewallWill]

You guys!! So it would look like I'm on for at least a carb/mixer regardless. Either another 225 to run a dual carb setup or a single 425. The hat for the turbo is the mystery item for me. Any suggestions for how I split the charge pipe from the turbo and could the turbo keep up or are we just moving the line. Small turbo to start, large replacement turbo for the dual carb setup because the little guy isn't enough. Lovin' this stuff.

 

[pmuller9]

The turbocharger size depends on the engine displacement, the rpm range it will be making power at and the amount of intercooling.
It doesn't matter how many carburetors/mixers it will be blowing thru as long as the mixers are sized properly for the engine displacement and power band.
You can use a single turbo with a "Y" split to the hats.
If you use a "Y", the two legs going to the hats need to be close to equal length.

Are you keeping the 240 or going to a 300 six?

 

[WhitewallWill]

The turbocharger size depends on the engine displacement, the rpm range it will be making power at and the amount of intercooling.
It doesn't matter how many carburetors/mixers it will be blowing thru as long as the mixers are sized properly for the engine displacement and power band.
You can use a single turbo with a "Y" split to the hats.
If you use a "Y", the two legs going to the hats need to be close to equal length.

Are you keeping the 240 or going to a 300 six?

Thanks for the clarification on the turbo, sitting at computer searching out another problem with our disk/drum distribution block. Anyway, I haven't pulled a plug yet to figure out our stroke length to confirm displacement as we are focused on getting on the road for this upcoming weekend.

Budget would suggest keeping what we've got so if there is a Y hat available I like that idea. I could install the turbo for the single setup we have then Y the Hat with the larger list of bolt ons including our intake in whatever iteration we decide on. The dual carb idea with our homemade log intake seems like an easy segue and certainly ups the cool factor. The intake is not ready for final decisions but, cutting in 2 single port plates wouldn't entail any additional work over what we signed on for to begin with.

 

[pmuller9]

I could install the turbo for the single setup we have then Y the Hat with the larger list of bolt ons including our intake in whatever iteration we decide on. The dual carb idea with our homemade log intake seems like an easy segue and certainly ups the cool factor. The intake is not ready for final decisions but, cutting in 2 single port plates wouldn't entail any additional work over what we signed on for to begin with.

It would be two separate hats, one for each mixer and a "Y" connection between the hats from the turbocharger or intercooler.
You would use Silicone tubing to make the connection from the "Y" to the hats.

Or a Silicone "Y" with metal tubing connections

Or you can use an intercooler with a single inlet and dual outlets

 

[WhitewallWill]

It would be two separate hats, one for each mixer and a "Y" connection between the hats from the turbocharger or intercooler.
You would use Silicone tubing to make the connection from the "Y" to the hats.

Or you can use an intercooler with a single inlet and dual outlets

Good to know such a thing exists, up until a few hours ago I didn't know I 'NEEDED' it.

 

[WhitewallWill]

I see the Impco 200 ease for plumbing especially with a right and left version available. Looks like going with the multi carb would be simplified with this approach. Spent some time on Raso Enterprise's site. My learning curve is pretty steep right now. Best to approach this with an analysis of the power we can get from a single 225 vs dual 200 or dual 225's (which internally are supposedly the samish as the 200's). I will look into tacking our manifold together soon so we will be ready for mockups this winter. The price of propane helps with consumption but, I'm taking opinions on what living with any of these options would feel like. The single 225 has run fine NA. My question would be will turboing this carb be enough. In it's simple form it might make sense to turbo using the stock manifold with our hat then decide if I will do single or dual carb on our homemade manifold I can't answer what ENOUGH is for me yet but, 250 horse would likely be close enough to target with the balance of the engine built well. Decisions. To kick off, exhaust is the quick and easy and with the turbo it could be a good start. There's our starting path.

Jay storer
Looks like he used 2 200 mixers/ carburetors

View attachment 12393

 

[WhitewallWill]

Stuck a wire into the #1 plug hole and cycled it to find we had a 3-7/8" stroke so we have a 300 with a 240 head. Looking in the hole it looks like we have dished pistons. Drove to work a few times this past month. The T18 transmission is holding it back. Starting fabrication to mount the turbo in the back. Planning 3" single exhaust to the turbo and maybe 2-1/2" charge pipe back to the engine bay depending on how much room I have getting past the Z bar and steering linkage. V8 crowd, when I mentioned it had a 6 a guy remarked we had a ways to go.

 

[WhitewallWill]

Well, it's been a while but, drove the truck the whole summer. Mocking up exhaust while driving so made a buck off the truck to make parts, made the 2 into 1 Y last spring. Getting piping sorted from the turbo back to the engine bay. Intake is getting welded now and checking in with experts on dual vs single mixer size before cutting carb plates. Did some panel striping and slapped some real whitewalls on. New Master and booster. More work on inner fenders.

 

[WhitewallWill]

Not quite done yet but, in progress.