Horizontal Cummins

[tcolley]

Looking for a serial number for an aftercooled horizontal Cummins to source some parts for one that was originally an upright engine. Probably a Crown application with a Big Cam. Also would be interested in a complete horizontal Big Cam. Thanks.

[HB of CJ]

Try the various Crown Supercoach or Gillig sites.  I think the blocks and stuff were the same with only some Crown specific pancake parts.  Same with Gillig.  My 1974 Crown (VIN 37317) had a Small Cam 250.  Lots of the stuff would have bolted right up from the old up right Big Cam series except specific pancake Jake parts and upper rocker box oil drain stuff.  Also obviously the pan.  All the major inside stuff was the same.  I think (?) the "pulse exhaust" manifolds were slightly different for the pancake turbo mounts.  Hope this helps or PEM if 'ya wanna'.  HB of CJ (old coot)

[tcolley]

It's a pancake specific part that I'm looking for, only my engine started life as an upright so my engine serial number won't show what I'm looking for in the parts breakdown. I need the intake crossover for an aftercooled pancake engine. It's different that an upright because the mounting of the turbo is different. The 350 in my bus now is supposed to have an aftercooler on in but the previous owner kept the intake from the original 335 because of the lack of said intake crossover. So I'm trying to locate one and put the aftercooler on the engine like it's supposed to be.

[HB of CJ]

Cummings had many different arrangements for the plumbing to fit.  If you could access a big dealership, perhaps for a small fee they would let you look through their manuals?  Are you going to run an air to air inter cooler, or a water cooled water radiator supported after cooler?  Both worked just fine up to about 400 hp.  Or PEM with a snail mail contact address.  I think I still have some engineering drawings somewhere.  Never threw them out.  HB of CJ (old coot)

[tcolley]

I'll be running the stock Cummins water jacket aftercooler, no air to air. I've run several Big Cams like this making around 550hp and they all did fine. I went to my local Cummins shop today and wasn't able to put his hands on the parts book for the pancake motors. The easiest way to find what I need is to start with the serial number of an actual aftercooled pancake engine and my Cummins parts guy can pull it right up on the computer. If I can't track one down then I'll be on the hunt for a horizontal Big Cam parts book.

[Iceni John]

I've posted this thread on the Crown Coach Junkies forum  -  maybe someone there knows the answers?

John

[HB of CJ]

Sorry for any confusion.  I was alluding to the left side type radiators on Crowns.  They can support about up to around 400 hp.  More for short periods of time.  Pulling the air through that big fan and relying on the air pressure differential method of cooling is the limiting factor instead of like a normal tractor front end radiator with the road speed wind blast.  Hope this helps.  HB of CJ (old coot)

[Iceni John]

The only reply I got from a CCJ member is:
I have a 1975 Crown with a NHHTC-335-FFC. It is not aftercooled. Aftercooled engines have an A in the model number. The shop manual for the 855 does not list an aftercooled pancake engine. The aftercooled engines listed are of higher HP than the pancake. I think the air intake crossover for the upright engine might be the part he is looking for. Hope this helps.

Another CCJ member from Hawaii said:
Guy contacted me on my Crowning Around site John............I'm dredging up a data plate for him.............
Is that you?

I don't know of anyone who's converted an upright Cummins for a mid-engine Crown or Gillig, but there's probably one somewhere!

John

[HB of CJ]

Cummings probably did not market a larger than 335 pancake Big Cam because of the lack of market.  No need.  More power was not required in a Crown or Gillig.  Having said that, memory now suggests, (always suspect) that there were some odd ball turbo inter cooled or after cooled pancake Big Cams used in very high altitude mining applications like in South America.

Also possibly in high altitude rail road self propelled passenger cars?

We were going to use BC factory USED 475 parts including pistons, cam, lifters, injectors, fuel injection pump, transfer feed pump, crank balancer, large fuel lines and a custom air to air inter cooler placed in front of the left side mounted Crown Supercoach radiator ... plus a big "Map Width" BIG turbo along with a nice big V12 air filter, custom air intake and a low resistance exhaust system.

About 300 pounds of fuel pressure, about 35 pounds turbo boost.  About 500 hp with about 1500 to 1600 torque.  Mechanical variable timing.  Advanced timing in the low side, retarded timing in the high side of the appropriately sized Fuller 10 speed Roadranger.  Probably 1750 U joints or equal.

Then we found out that the heat rejection over about 400 hp would have overwhelmed any type of OEM or close Crown Supercoach radiator.  Then illness struck and the Crown was sold.  Oh well.  HB of CJ (old coot)

[tcolley]

I got it all sorted out. Crown did put some aftercooled pancake Big Cams in some busses in the 80's and I was looking for a serial number for one of these. Pretty sure they didn't make a pancake Small Cam. My Gillig originally had a 335. When it crapped out the previous owner replaced it with an upright aftercooled Small Cam 350 using all the pancake parts from the 335. Except he couldn't keep the aftercooler on the 350 because the intake crossover for an aftercooled pancake engine is different from the crossover on the upright engine. I picked up a parts book off of Ebay for Big Cam pancake engines which includes an aftercooled 350 so I was able to obtain the part number I needed from there. $740 from Cummins but found a used one at an equipment dealer in Wisconsin for $375. I'm gonna get it bought tomorrow and hopefully have the aftercooler on the bus in the next couple weeks.

[Iceni John]

One of the CCJ members has a unique Crown RV factory-converted from one of two mobile labs that Crown built for Hewlett Packard.   I think he said (but I could be wrong) that his bus has 375 HP from its Big Cam  -  if that's true, I guess he would have an aftercooled engine?   Whatever he has, his bus just cruises!

John