Yank Tank Molotov/3+3, 454/magnum/Allison

[SpeedlabDan]

I think Larry mentioned it in the 8.1 thread, or is polar bear burb thread. But even before that we both had to deal with the problem at Workhorse. The issue was bad enough due to improper grille opening sizing by the coach builders and other issues they built in we had to come up some extra cooling to get some air back there.

We ended up creating a kit mounting a scoop under the bumper on each side with 4" brake cooling ducts routed to force air right at the 5/7 and 6/8 plug wires. I had AZ in my region at the time and had them dropping like flies out there. Took the worst case that was killing them in 500 miles towing his bass boat with the RV to install a prototype kit (proof of concept) with home depot parts. Ended up using 4x10" floor vent registers for the scoops and 4" corrugated/segmented dryer ducts. Pre-install driving up I-17 out of Phoenix had the stock manifolds running over 1200 degrees on a 6% grade climbing. Post install had the temps down below 500 degrees for the same grade. We were pushing so much air back there it was causing the dog house cover on the floor to lift an inch off the floor at highways speed. We ended up installing two extra latches to keep it down.

Hahahaha wow! That's serious! This stock mechanical rad fan moves so much air I can pull it in the shop an blow all the dirt out of the shop if I Rev it. I guess that's why it uses such a large fan

 

[ZooMad75]

Hahahaha wow! That's serious! This stock mechanical rad fan moves so much air I can pull it in the shop an blow all the dirt out of the shop if I Rev it. I guess that's why it uses such a large fan

The thing was the fan and clutch spec'd out for the Workhorse chassis is even bigger than the GMT800 truck stuff. When the clutch kicked it the sound was like a small prop plane on a take off roll. Some customer's got annoyed at the sound until I told them, if you don't hear it and it's hot outside you better look at the temp gauge because it's probably going to overheat. The issue came down to crappy airflow. I had one customer that was a retired aero-engineer (wind tunnel jockey) and he took little inch long scraps of his wife's knitting yarn and taped them in a pattern on the valve covers and intake and then drove it with the doghouse cover off. He confirmed what we suspected that the airflow at the rear two cylinders was little to nothing even at highway speeds. Add to the fact the way the manifolds are setup, the flow from the front two cylinders goes back to the rear of the manifold allowing more heat to be absorbed into the rear half of the manifold.

At 500 degrees a stock 8.1 exhaust manifold is a dull cherry red color. Those are cast stainless steel by the way. At 1200 degrees they are almost white.

 

[SpeedlabDan]

The thing was the fan and clutch spec'd out for the Workhorse chassis is even bigger than the GMT800 truck stuff. When the clutch kicked it the sound was like a small prop plane on a take off roll. Some customer's got annoyed at the sound until I told them, if you don't hear it and it's hot outside you better look at the temp gauge because it's probably going to overheat. The issue came down to crappy airflow. I had one customer that was a retired aero-engineer (wind tunnel jockey) and he took little inch long scraps of his wife's knitting yarn and taped them in a pattern on the valve covers and intake and then drove it with the doghouse cover off. He confirmed what we suspected that the airflow at the rear two cylinders was little to nothing even at highway speeds. Add to the fact the way the manifolds are setup, the flow from the front two cylinders goes back to the rear of the manifold allowing more heat to be absorbed into the rear half of the manifold.

At 500 degrees a stock 8.1 exhaust manifold is a dull cherry red color. Those are cast stainless steel by the way. At 1200 degrees they are almost white.

Wow I hope my long tube stainless headers don't melt off haha! Hopefully there's good enough flow in the bay brub it's higher and fretty open underside, the po removed the circular 4" punch outs from the rad support so there's a little more air too

 

[sweetk30]

Do I need to post a poll about plugs? Nah its unanimous.

you the search button before you do this you nobb . there has been over 2dozen polls i bet on this .

 

[SpeedlabDan]

Th

you the search button before you do this you nobb . there has been over 2dozen polls i bet on this .

That's why I said it

 

[SpeedlabDan]

Started tinkering with the tcase shifter today. Had to mill an 1/8" off the rear shift rail lever to sneak it in the recess of the magnum box. It's almost all the way encapsulated so this will save me from divorcing the mag and the tcase now and in the future to remove it. Also picked up the rebuilt military front shaft with new boot.

 

[TuckerK5]

Where did the blue come from?

 

[SpeedlabDan]

Where did the blue come from?

That was the original color. The dark garnet red metallic is a repaint

 

[TuckerK5]

That was the original color. The dark garnet red metallic is a repaint

Are you staying with the red?

 

[beags86]

Where did the blue come from?

I would go back to the blue if you like it.
That red just don't belong

 

[SpeedlabDan]

View attachment 287426


I would go back to the blue if you like it.
That red just don't belong

I QUOTE that line all the time but no I like the red

 

[SpeedlabDan]

Are you staying with the red?

Yea for now it's a cheap job with lots of overspray that's good at 20 feet but I like that I don't have to worry about it

 

[TuckerK5]

Ain’t nothing wrong with building it from the inside out.
Mine looks better at 20’ too.

 

[SpeedlabDan]

Ain’t nothing wrong with building it from the inside out.
Mine looks better at 20’ too.

Yea i always prefer something be mechanical solid before it's pretty. That's the problem with my k5, it looks great but it's not where I want it mechanically.

 

[SpeedlabDan]

Put some high pressure -10an trans lines in and had to detach the Allison dip stick from the bell housing bracket. The lip on the fire walk that I didn't want to hack up was pushing the tube forward just enough to pull out of the trans. I can't fully remove it while in the truck to modify the bend and or the bracket.

 

[SpeedlabDan]

Finished up the install of the jb fab triple stick. Nice shifter but it was way more tedious than I anticipated. Really tricky getting everything to lay nice all at the same time. Glad I went with the 60" cables but I still have to come up with something to hang them above the drive shaft.

Tomorrow I'll put a new master cylinder in and bleed then the front drive shaft. Can't wait to try it!

 

[beags86]

Put some high pressure -10an trans lines in and had to detach the Allison dip stick from the bell housing bracket. The lip on the fire walk that I didn't want to hack up was pushing the tube forward just enough to pull out of the trans. I can't fully remove it while in the truck to modify the bend and or the bracket.

View attachment 287805

Fleece?
Those look super high quality.

 

[SpeedlabDan]

Fleece?
Those look super high quality.

Yes

 

[beags86]

Yes

Any particular source?

 

[SpeedlabDan]

Any particular source?

Direct from fleece performance