DNFXDLI's 79 F150 Build Part 2

[DNFXDLI]

Okay Duncan why such a high stall speed on the converter????

Well...let me clarify..could be between 24-2600...next step down was 22-2400. It boiled down to what was going to be more fun

 

[blackhat620]

Well...let me clarify..could be between 24-2600...next step down was 22-2400. It boiled down to what was going to be more fun

More fun!!! in a street driven 4-wheel drive truck. High rpm's are usually not very conducive to truck applications especially 4x4's. Plus high rpm torque converters produce extreme amounts of heat in a street driven vehicle.

Most stroker applications for trucks the object is to keep the power band in the low rpm range. Generally speaking for a streetable vehicle you want your torque converter stall speed to be 750 - 1000 (500 minimum) rpm's below max engine torque rpm.

What duration cam are you running and what is the projected torque power band?

As for your gearing if you leave the current 3.50 R&P and switch to taller tires then you will lower your cruise rpm at all speeds so at 70 on the highway your 2600 rpm torque converter will be unlocked creating lots of extra heat on the transmission.

 

[DNFXDLI]

Max torque should be achieved at 3200-4000 rpm, which should be around 525+ at the crank. Cam duration is 224/232 @ .050...roller. Rpm with gears in place should be roughly 2600 at 70 mph with 32's...hence my thought of dropping the gear to a 3.73...which would bring it to roughly 2700. The flipside is that it could stall at 2400 ish...not really going to know 100% until it is driven.

 

[blackhat620]

Max torque should be achieved at 3200-4000 rpm, which should be around 525+ at the crank. Cam duration is 224/232 @ .050...roller. Rpm with gears in place should be roughly 2600 at 70 mph with 32's...hence my thought of dropping the gear to a 3.73...which would bring it to roughly 2700. The flipside is that it could stall at 2400 ish...not really going to know 100% until it is driven.

As you stated you will not know for sure until it is driven, that being said unless you know your torque converter builder very very well and have worked with him before, If it was me, I would put the stock converter in it then drive it and run a dyno on it. With a dyno graph, vehicle weight, transmission gearing, R&P gearing, desired shift points, along with letting the TC builder know that it is a no locking, non-OD trans along with how much street driving compared to track use you plan to do then a proper TC could be built.

If you choose to install a new TC before you dyno & drive the truck then make sure your TC builder has all the data you can supply and err to the low side on stall speed. If you wind up with to high a stall speed on this for street use you are going to end up cooking alot of transmissions.

 

[DNFXDLI]

Both the TC builder and transmission builder are good...everything from heads to cam etc. were discussed with the TC supplier. Also keep in mind that both 1st and 2nd gear sets are changed to keep the revs higher. And it goes without saying, but I'll say it anyway....the temp will be monitored..this is not a cheap transmission..I have no intention of frying it

 

[blackhat620]

Both the TC builder and transmission builder are good...everything from heads to cam etc. were discussed with the TC supplier. Also keep in mind that both 1st and 2nd gear sets are changed to keep the revs higher. And it goes without saying, but I'll say it anyway....the temp will be monitored..this is not a cheap transmission..I have no intention of frying it

Duncan,

I understand not "frying" the trans but it all depends on how you are going to drive it. On the track you can always go fast, around town or in the dirt that gets difficult. Now if you had a locking TC I would be less concerned but generally for a street driven vehicle I run the lowest stall speed converter I can get away with without bogging the engine off the line or not being able to let it sit & idle in gear. The only place a higher stall speed gains you anything is better launch off the line to lower your 10 foot et, so unless you plan on doing a lot of WOT launches off the line I just don't see the benefit of a high stall TC on a street application, compared to the downsides.

If I were you I would definitely choose a low enough R&P that you are not having to downshift while going down the road at 50 to keep the trans cool.

 

[DNFXDLI]

I don't think there will be any problems, if I were towing or carrying a heavy load then I would reconsider. The factory numbers for a 400 are 16-1900 rpm stall and there are many times where a vehicle is doing 30 mph and doing under those rpms'. I do appreciate you input however...you shoud be posting more often

 

[Fordzilla80]

A part deux with no pictures...

 

[DNFXDLI]

Don't worry, it will happen

 

[blackhat620]

Don't worry, it will happen

Yes but will that occur in this century?

 

[DNFXDLI]

Yes but will that occur in this century?

Owww...that's kinda harsh....
All I did today was more grinding, blasting and prep. Sorting through all the fasteners to see which ones can be cleaned and dryfilmed...and which ones I need to go and buy.
Also cursing the Ford shop manual coz I can't find the clutch fan

 

[Mil1ion]

What do you need that for ?

 

[DNFXDLI]

What do you need that for ?

To see if there is an exploded view and what that spring in front does...I need to clean it before getting it dryfilmed.

 

[Dirky]

To see if there is an exploded view and what that spring in front does...I need to clean it before getting it dryfilmed.

What is this "dryfilm" you speak of? Some sort of corrosion inhibitor I assume.

 

[DNFXDLI]

What is this "dryfilm" you speak of? Some sort of corrosion inhibitor I assume.

Yes..used on oilfield stuff. Very durable and thin...bonds to the surface and you can do threads etc. without issues. It comes in a few different colors as well.
It's a bit more costwise than powder, but is applied cold.
http://www2.dupont.com/Coatings_and_Release_Systems/en_US/products/dryfilm/dry_film_products.html

 

[Mil1ion]

http://www.rockauto.com/catalog/moreinfo.php?pk=815313

Temperature controlled the spring expands as it heats and causes the clutch oil to GRAB the turning spindle thus taking the fan from feathering to vicious mode.

 

[DNFXDLI]

http://www.rockauto.com/catalog/moreinfo.php?pk=815313

Am I missing something?

 

[Mil1ion]

 

[DNFXDLI]

I'm looking for an exploded diagram to see how the shaft is sealed...to determine how to clean it.

 

[Mil1ion]

i used lacquer thinner and water then a blast of air


http://www.google.ca/imgres?imgurl=...a=X&ei=nboHTviDH5KisQPO1P21DQ&ved=0CDwQ9QEwBA