I did do a little more research on the OEM and After market pumps and must agree that the 3 stage pump is definitely better than the OEM... I took a good look at the OEM pump and the 1 scavenger gyrator that is servicing both the Wheel side of the case and the Cam chest and this is the question I asked my self.. What happens when the cam chest is done scavenging (no oil) but yet the wheel side still has oil in it? Does the OEM oil pump start sucking Air from the cam chest side which will impede scavenging on the wheel side.. I'm not an engineer but I do know that once air is introduced to the system it will hamper the pumps ability to do it's job.. The other thing I really need to emphasize is that like back when Shovels and Evo's were the main ride and when it came to the cam chest all the bushings for the cam and pinion shaft they were Bakelite, Manganese Bronz or similar type of material (brass) that will hold more lubrication then just a machined piece of Aluminum.. And I really don't care how hard it is 3061 or what ever 29775 whatever the number..... Aluminum is a not the greatest for bushings... So I will be getting an S$S plate and Pump.. Like anything else, when you do a build you don't want to short change yourself.. You get what you pay for and I don't want to pay for a headache down the road...
Funny you mention sucking air. Another thing I noticed immediately was no aeration in my oil tank. Aeration impedes the oil from doing its job properly too. More than most think.
No way would I spend the money I did on this engine and not put a 3 stage pump in. Especially with the rpms I run. Imo it should be stock. Just my opinion but the improved scavenging was obvious from day one.
I.posted before and after pics of the oil in my tank last summer.
My crank run out was .003 and I did an S&S anyway. Besides wanting to build one of the best 107s, my purpose was to address all the weak points of a twin cam. The crank and oil pump are two of them. So was the crankcase venting.
You don't need to full on sump to.have sumping issues either. IMO 7oz of oil left in the sump at all times is a.sumping issue with negative effects and one that can corrected with the DT pump and plate. And S&S since it's a copy of Dan's pump. Or so the story goes anyway.
Incidentally the Dan Thayer pump and plate requires no crank runout. Or less than .003 anyway.
Another thing I like is the big oring sealing the pump to the plate.
Datsun was doing parent metal overhead cam bearings in the late 60s. Back in the 80's, early 2000's had both a 68 and 69 Datsun 2000 roadsters. I rebuilt both engines. Fast little cars
Funny you mention sucking air. Another thing I noticed immediately was no aeration in my oil tank. Aeration impedes the oil from doing its job properly too. More than most think.
No way would I spend the money I did on this engine and not put a 3 stage pump in. Especially with the rpms I run. Imo it should be stock. Just my opinion but the improved scavenging was obvious from day one.
I.posted before and after pics of the oil in my tank last summer.
My crank run out was .003 and I did an S&S anyway. Besides wanting to build one of the best 107s, my purpose was to address all the weak points of a twin cam. The crank and oil pump are two of them. So was the crankcase venting.
You don't need to full on sump to.have sumping issues either. IMO 7oz of oil left in the sump at all times is a.sumping issue with negative effects and one that can corrected with the DT pump and plate
Incidentally the Dan Thayer pump and plate requires no crank runout. Or less than .003 anyway.
Another thing I like is the big oring sealing the pump to the plate.
Sorry you have to have some aeration .. To test is you like, dump a pint of MMO in the motor oil when 1/2 qt low..
Datsun was doing parent metal overhead cam bearings in the late 60s. Back in the 80's, early 2000's had both a 68 and 69 Datsun 2000 roadsters. I rebuilt both engines. Fast little cars
Not sure how I found this thread, but I’m obliged to comment. ’69 2000 with factory 44 MM Mikuni Solexes, and performance cam. If I got that all right.
Bought in 1981 from a customer, and ran it up through the woods backwards in around 1983 due to old tires in the twisties with a girl I had known maybe twenty minutes.
Not sure how I found this thread, but I’m obliged to comment. ’69 2000 with factory 44 MM Mikuni Solexes, and performance cam. If I got that all right.
Bought in 1981 from a customer, and ran it up through the woods backwards in around 1983 due to old tires in the twisties with a girl I had known maybe twenty minutes.
I blew one of those up.. Overrevved it and bent 3 exhaust valves.. With 250 miles on it..
Sorry you have to have some aeration .. To test is you like, dump a pint of MMO in the motor oil when 1/2 qt low..
I'm never low enough to have to add oil now that I can run on the full mark and not puke oil. That's the better crankcase venting tho. Running a half quart low is not the answer to **** poor crankcase venting.
I'm sure there's probably some aeration being created just from the return oil hitting the tank. I don't see the air bubbles I use to tho that's for sure.
Btw, I agree with shooting for 200psi CCP as a minimum. I'm running 212psi and I have no issues even on hot 90°+ days.. Not sure where the standard of 180 came from except there's many running without a good tune I'm sure. There's a direct correlation between compression and cylinder fill aka power. Not just low end either but top end as well carrying out further.
If I did decide to go to the 110" kit, how many of you would do the Flat tops @ 10.67:1 or the 3 cc domes @ 11.2:1 as shown with the Big Boys attachment? I will still use the Woods 888 cam. I'm confident I can tune it..
My bad on the Dyna; got it confused with the Fatboy. Still don't see a sumping issue but; like you, I ran the DT pump in the all bore 107 in my '02 FLHT and the S&S in the current 98" in my '05 FXSTD. LIke I said in my previous, if funds are available, why not?
I see you are re-thinking the 110 kit? Anytime I can get the targeted results with flat top pistons, I will go that route. I think you will regret not going the bigger bore route. JMHO.
My bad on the Dyna; got it confused with the Fatboy. Still don't see a sumping issue but; like you, I ran the DT pump in the all bore 107 in my '02 FLHT and the S&S in the current 98" in my '05 FXSTD. LIke I said in my previous, if funds are available, why not?
I see you are re-thinking the 110 kit? Anytime I can get the targeted results with flat top pistons, I will go that route. I think you will regret not going the bigger bore route. JMHO.
Most likely would regret it if I didn't do it but I am a little concerned about putting that much power to a crank that already has .005 runout... Most likely 3000 rpm hole shots would be out of the question @125/125...
02-25-2023, 08:48 PM
With 250 miles on it..
That's the better crankcase venting tho. Running a half quart low is not the answer to **** poor crankcase venting.
