79 F-100 Turbo 300-6 Sleeper

Thank you for posting here
I read through your build on FTE.
Very creative solutions and lots of great info.

One observation: Some of the aggressive Lunati lobe profiles have caused lifter stability problems after 5000 rpm on other engines.
The Lunati cam was switched out to a different cam and the problem went away
I'm wondering if that could be contributing to the rpm "brick wall" affect you are seeing.
 
Sick - love your build. I need a oil return pump for my new build , do you think your setup would work at 6500 -7000 rpm.
Thank you.
 
pmuller9: It could be. Although I have seen it with all the cams I've tried, the Crower only pulled to 5200 after the turbo change to the Gt45. It was a brick wall 5000 before that. I haven't checked back pressure with the 277 and the gt45, I think it's higher than with the Crower, It sounds mean again and spools quicker.

Blowing through the converter with this combo and the v6 combo t-bird all were brick walls. Kind of nice showing peak hp rpm. Perhaps the converter is playing a part as well. Will know more when the Pro Edge is re-stalled and back in. When the converter was cool the other day, it pulled to 5600 in first. Drove around to cool off a bit and tried again, had a hard time getting to 5600.

Glad to be here, I enjoy your posts and many others here that really know their stuff. :beer:

I also wanted to add, even though the engine and trans are dirty etc.., I use extreme care keeping the internals and gasket surfaces clean when working on the truck. If I decide to stay with this project, it will eventually look pretty. :nod:
 
drag-200stang":1kem8thh said:
Sick - love your build. I need a oil return pump for my new build , do you think your setup would work at 6500 -7000 rpm.
Thank you.

Thanks, love yours too!

Not sure if the diaphragm in the fuel pump would take the rpm's for long or hold up. I do run a .0625 restrictor due to a previous set up, and left it in without issue so far. I think the reservoir/plumbing would be ok. Been keeping an eye on one of these if I run into trouble: http://www.ebay.com/itm/NewBlack-Perfor ... SwkZhWRqSg
 
:banana: Slick6Turbo, that's a really excellent write up on your trucks turbo build up! : (y) I have always loved the sleepers too theirs nothing like beating somebody in their high dollar car or truck with one! :beer:
 
I really like the layout with the rear mounted turbo.
The engine compartment looks uncluttered with lots of room to work.

I went over your very well done write up a second time including your comparison between cams versus rpm.
I have a turbo 300 project coming up so I have an interest in your results.

One of the areas of concern is the exhaust manifold.
The log manifold sees exhaust pulses running the full length of the log every 120 degrees of crank rotation.
The exhaust valve opens somewhere around 70 degrees before BDC and the blowdown portion of the exhaust cycle begins
and continues till pressure equalization just after BDC. The rest of the cycle is dedicated to pumping the remaining exhaust gas out of the cylinder.

The exhaust valve of the next cylinder in the firing order opens 120 degrees after the previous sending a pulse from the opposite end of the log.
This pressure pulse reaches the previous cylinder while its exhaust valve is still open, early in the pumping cycle which raises cylinder pressure.
This increases pumping losses and more importantly it will take a lot higher rpm before intake port reversion is overcome.
In any case it delays the start of cylinder fill when the intake valve opens at all rpms.
Just as a side note:Here the piston is always under compression and does not get hammered at the top of the exhaust stroke. One of the reasons they survive.

The piston reaches max velocity at 74.3 degrees ATDC so any delay in charge motion after the intake valve opens decreases the time for the piston to transfer its kinetic energy to the incoming charge which lowers port velocity decreasing cylinder fill ABDC.
The intake duration is effectively shortened at both opening and closing and as the duration is increased there are diminishing returns.

The EFI exhaust manifolds isolate the back three cylinders from the front three. Now there are exhaust pulses every 240 degrees of crank rotation in each manifold instead of 120.
Much less negative interaction between cylinders
Secondly exhaust manifold runners collect in parallel like a tube header collector and can actually create a scavenging pulse behind each for the benefit of the next.

As you can tell I recommend putting the EFI exhaust manifolds back on.
Run about 18" of pipe beyond the flanges before collecting the two pipes with a "Y".

You should see the rpm "Brick Wall" change to a easier roll off at a higher rpm with a lot more power through out the power band.
 
subscribing to this thread as well, awesome read and info at fte, and loads of info here and tons of good guys to chat with.
 
Thanks guys!

pmuller9: The brick wall is from blowing through the converter. There is just enough left in this converter when cool(not been boosted), that is stalls to 4700 and pulls great leveling off slowly such as 5600 rpm described earlier. After is has been boosted once and the fluid is warmed up, it shoots to 5200 and stays there. You really have to actually ride in a turbo car that's blowing through the converter to get a good grasp of whats going on. Andre at Edge Converters confirmed that it can limit rpm. The other v6 was the same way, until the new converter.

I have put thought in the exhaust pulses, and also considered different cam profiles catering to the 120* firing. You cam and ignition lead a 5hp racing Briggs and Stratton differently than a multiple cylinder engine as well. Low timing helps pulling out of the corners toward the checkered flag on those...anyway... The whole exhaust system is under pressure fluctuating 5psi pressure with pulses on my best gauge. Depending on flow, anything with a Y in it and more time could cause reversion up the other pipe, not good. The log on the other hand, is like a balloon with six straws in it. Don't matter which straw is blowing or when, its flowing out the hole. The efi mani's have terrible bends in them detrimental to flow and reversion could occur there too.

The bottom line: I have see horrible turbo plumbing to the turbo, only to be done proper later with zero benefit. Real world testing is the only way. My truck spools great with excellent back pressures, no reason to change things. I do understand where you are coming from in theory however. The efi mani's could work better, headers with proper heat treatment could work better...Their is a guy selling 1000hp mod motor turbo kits, he will sell you his headers or you can use your manifolds. He said dyno testing showed no difference in power.

Agreed, turbo boost keeps pressure in the cylinder and on the piston....keeping the rod alive. Low timing and proper AFR's save pistons and head gaskets.
 
Sick6

Thanks for the more detailed explanation of the converter problem.
Had a similar problem with a nitrous car. Car was fine on motor running 9.10 ets.
The owner wanted 8s so on went the nitrous, engine went to 7200 rpm and stayed there through 2nd and 3rd gear. Ran an 8.8 1/4 mile but it was strange.

A few years back was involved with 10.5" tire outlaw class as well as NHRA top sportsman. Twin 88s on 430 cid SBF over 2000 hp
I was recording both manifold and exhaust pressure with Racepak sensors. Average manifold and exhaust pressures were the same, 1:1 ratio.
With pressure sensors I could see exhaust pressure at the collector going down to zero and up to twice the average pressure.
This was a good indication that pressure and scavenging pulses existed along with good isolation between cylinders.
That was with large tube equal length primary pipes to the turbine flange.

The advice I got from those racing the 300 recommended the efi exhaust.
With 18" of pipe after the manifold flanges before the two are collected there is enough velocity and air mass in each pipe to prevent reversion.
The pulses coming out of one pipe is 180 degrees out of phase with the other which creates scavenging for both as they meet and travel down the single pipe.
The consensus here is that a full length header is worth more when open but loses its advantage over the EFI with back pressure from an exhaust system.

I wasn't thinking about improving the spooling as much as finding you more horsepower.

I appreciate your input
 
Good stuff pmuller9.

I think you are correct, there would be enough velocity to prevent reversion with the Y's. Also, the bends may not be too detrimental to flow but do lose heat as seen in dyno videos, bends glow cherry red first. I have been considering coming out of the h.d. mani laterally rather than down improving flow and heat retention, along with other bends in the feed pipe that are no long needed because of cross member removal. I may do all these things and yield no noticeable improvement!

There have been guys that tried headers with rear mounts, and put the manifolds right back on. On the other hand, there is also a guy that used headers and gradually stepped down pipe size on the way back to the turbos and claimed there was no difference in e.t. or spool from front mount. This throws a wrench into velocity vs. flow debate, and may be the best of both worlds. I have considered coming out of the mani with 3" and stepping it down gradually to 2.5" at the turbo. My thought is the hot expanded gasses aren't forced into a 2.5" pipe so soon and the heat is carried farther downstream. The pipe size shrinks along with the gasses keeping velocity stable with less restriction.

On that note, perhaps the log works best with the 13+ foot long 2.5" "header" on my truck. Maybe the efi mani's would not work any better with the long 2.5" pipe, but could work better than the log/2.5" straight combo if stepped down more gradually on the way to the turbo??? Trying it is likely the only way tell.

A big monkey wrench in the gears is this: Drove the truck with a friend taking video of the back pressure gauge for safety. Boosted the truck, drove a mile to cool tranny, turned around and boosted the truck from a 20mph roll similar to the other videos. The truck pulled harder than it even has, getting squirrelly but hooking enough to pull hard. Finished up and parked the truck. Went to take my brother for a ride a few days later and no boost. The 2.5" exhaust pipe had shrunk and pulled out of the slip coupler that is about 2/3 the way back. Made some adjustments and welded it solid. The truck never pulled that hard again. Brings a whole new element to turbocharging with a possible adjustable exhaust venturi in the mix!

Thank you for the idea's, and effort. I will experiment down the road and may wind up with efi mani's...my main focus now is to settle in on a cam and turbo combo so further testing can be apples to apples.

Have a Merry Christmas!
 
Using the stock fuel pump as an oil pump for the turbo is just inspired thinking.
I'm really digging the hell out of your truck.

Congrats, great build.
 
Thanks gassercoupe!

I've worked on such an assortment of things for so many years, i'm drawn towards mechanical reliability and simple. If points ignition was accurate, that's what would be in the truck :nod:

I have also developed a system I call "the cure" for controlling the power valve in the carburetor externally to control fueling when boosted. It is similar to the "crutch", but is fully mechanical...no wires or motor to fail and has worked flawlessly for over 2 years on another vehicle, and flawless on mine. Adjustable and costs about $20 depending on what's available on ebay.

I would like to talk to Brent Davis(created the crutch) about "the cure" prior to releasing details out of respect as he is selling his crutch systems for around $400+.

I can tell you that the carb can be rebuilt to stock using a standard rebuild kit and power valve. Modify one circuit to channel control somewhere on the outside of the carburetor and plug the original power valve hole in the base plate or body. More details soon, will start a thread here when ready.
 
Well, it's time to say goodbye. I have decided to take a break from forums.
Good luck with all your builds and take care.
 
Sick6Turbo":1mjs0h6b said:
Well, it's time to say goodbye. I have decided to take a break from forums.
Good luck with all your builds and take care.
Dale
I'm really sorry to see you go
I appreciated you taking the time to share your projects and I learned a lot from them.
You really have some excellent "out of the box thinking" solutions.
Please reconsider posting here as you make progress.

Sincerely
Paul
 
late to the goodbye here however, hope to chat with you again sometime dale, as well. i will pm you with what i think of the cam and specs you suggested awhile back for a custom grind. i put an order in with lunati should be a few weeks away.
thanks
 
I see the valves on the table in the back ground and the manly box. Some more head work before the track opens?
 
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