Board index Flathead Power-Technical Questions, Answers, and Suggestions Big Twin Flatties Oil Pump

Oil Pump

Moderators: Curt!, Pa

Post Tue Jan 28, 2014 2:50 pm

Posts: 542
Location: Wa, USA
Today I received my new oil pump from Calas HP in Sweden. After 8 years of research, planning, testing and machining, the pump modifications I made failed horribly. I got less than 2 miles down the road and lost oil pressure. Crankcase internal pressures were so high that oil oozed out of everyplace possible including James bead seal cylinder base gaskets. About the same time as all this, I saw the reports on the Calas feed pump and scavenge pump upgrade. I stopped what I was doing and saved my pennies until I could afford to order them. Everything looks really nice and I am looking forward to getting it working. I will update this with installation and testing reports as things progress.

Post Wed Jan 29, 2014 3:17 pm

Posts: 216
Location: Georgia
I made the feed pump upgrade a couple of years ago. Works great. Please post pics and description of the return pump.
F

Post Wed Jan 29, 2014 4:23 pm
CHP

Posts: 14
fhsmith1 wrote:
I made the feed pump upgrade a couple of years ago. Works great. Please post pics and description of the return pump.
F

There are pics and a little video on our site. www.calas-hp.com

Carl

Post Wed Jan 29, 2014 9:22 pm

Posts: 497
Location: Six miles East of Cheney, Wa.
So what went wrong?

k.

Post Thu Jan 30, 2014 2:23 am

Posts: 542
Location: Wa, USA
Not really sure of the cause, yet. I suspect breather timing and possibly a sheared drive pin in the pump. After I saw the CHP pump, I knew that it was the way to go, and just parked the bike until I could get one. Now I will take things apart and make it all better.

Post Fri Jan 31, 2014 4:10 pm

Posts: 497
Location: Six miles East of Cheney, Wa.
Will be interested in hearing the post-mortem analysis. !! Good luck. (not that you need it)

ken

Post Thu Feb 06, 2014 9:53 pm

Posts: 11
Location: wisconsin
fhs, did you install scavenger and feed pumps or just feed pump?

Post Fri Feb 07, 2014 1:55 pm

Posts: 216
Location: Georgia
old man,
I just upgraded the feed pump. Still have original type return pump.
F

Post Sun Feb 09, 2014 3:44 pm
jib

Posts: 575
Location: devon,england
just seen this pump on ebay

http://www.ebay.co.uk/itm/HARLEY-DAVIDS ... 19e8268a74

looks like some of jims modifications n some improvements . jib
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Wed Feb 12, 2014 8:19 pm

Posts: 11
Location: wisconsin
F; full time crank oiling? If so:grooved pinion pin or pinion bushing? Piston oilers? Any sign stock return can't keep up with feed? MB

Post Thu Feb 13, 2014 7:08 am

Posts: 542
Location: Wa, USA
Started teardown yesterday. The oil filter was full of metal, so it looks like a complete disassembly for cleanup is in order. I should have it all apart today. The shavings in the oil filter appear to be all aluminum, so I think my oil pump modification ate itself.

Post Thu Feb 13, 2014 1:14 pm

Posts: 542
Location: Wa, USA
The plot thickens. The cam chest has a large amount of shavings in it. The oil pump shows no evidence of the kind of damage that would produce the amount of shavings present. The cylinders and pistons are scored, but no chunks missing from the pistons.

Post Thu Feb 13, 2014 7:23 pm

Posts: 542
Location: Wa, USA
Have the cases split and still no culprit. The only thing left to check is whether the aluminum rod bearing cages munched.
Image

Post Thu Feb 13, 2014 8:34 pm

Posts: 216
Location: Georgia
old man
I put mine back mostly stock. No full time rod oilers, no piston cooling jets.
F

Post Sun Feb 23, 2014 11:28 am

Posts: 542
Location: Wa, USA
It seems that all the crud in my engine was not shredded aluminum as it appeared to be. It is Devcon liquid aluminum epoxy. I used it to plug the hole in the right case where the cylinder stud holes break into the case when I drilled it for top cylinder oiling. The plug apparently loosened with age and the oil pressure pushed it out, causing a loss of oil pressure and filling the cam chest with shredded Devcon.

The new plan is to plug off the top cylinder oiler, groove the pinion bushing for full time oiling and rely on the increased output capability of the CHP pump to get enough oil to the cylinders. I am also saving for new S&S cylinders to replace my old tired sleeved cylinders. Despite everything I have tried, they do not appear to be able to handle the heat well any more.

Post Mon Feb 24, 2014 8:56 am
GuS

Posts: 368
Location: Bergen, Norway
Woody
Sorry to hear about your problems.
Hat off to you for sharing all your testing and progress even when it failed.
I have enjoyed following your progress and have learned a lot from you.
Thanks.

GuS

Post Mon Feb 24, 2014 1:58 pm
jib

Posts: 575
Location: devon,england
so woody , your modifications to the pump are still viable , just the devcon blocking the oiling passage a prob ? regards jib
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Mon Feb 24, 2014 6:40 pm

Posts: 542
Location: Wa, USA
Thanks, Gus.

jib,
There was no damage to the oil pump at all, so yes I think that the modifications are still viable. The two issues that caused the most problems were clearance problems between the frame and the extended return pump, and timing the breather because the sleeve is from a sportster and the timing mark is different. I decided to go with the CHP pump because it is just a much better idea and a much cleaner and easier installation. Even if I had not had the latest problems, I would eventually have made the change.

Post Sat Mar 01, 2014 9:00 am
jib

Posts: 575
Location: devon,england
woody would you like to sell that pump of yours , am putting wl/kh engine in a rigid triumph frame so n clearance issuses , regards jib, pm me if you like.
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Thu Mar 20, 2014 6:47 pm

Posts: 542
Location: Wa, USA
After more inspection, I found that the cause of this problem was that I used the pourable Devcon that remains flexible. I chose this because I thought it would be better than the very hard stuff because of the expansion rate of the aluminum. Apparently the oil pressure behind it was enough to push it out like a wine cork after you shake the bottle. I had this on the road previously with a stock pump with no problem. The increased pressure of the pump modifications was more than it could handle.

I was able to get enough good threads in the hole in the case where the stud holes break through using a 7/16-20 tap to use a set screw to plug the hole. I will loctite and stake the set screw to retain it.

The rod bearings look OK, but had a lot of Devcon smashed into everything, taking up all the clearances. Cleaning and reassembly starts this weekend.

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