Don Terrill’s Speed-Talk

Yes, the 74-30. Feels a lot like silcone sealer when it sets up. You can work it loose around the edges and spray a little wd-40 around it and push it out thru the valve opening. Takes 12-24 hours to set up.

Rick

What cam core did Comp use and the lifters are tool steel? How do they look and what oil were you running? There's been some discussion awhile back where running a nitrided cam with tool steel lifters was a big no no due to similar hardnesses?

Bob Hollinshead wrote: ↑Sun Jan 14, 2018 12:18 pm What cam core did Comp use and the lifters are tool steel? How do they look and what oil were you running? There's been some discussion awhile back where running a nitrided cam with tool steel lifters was a big no no due to similar hardnesses?

Regular cast core nitrided. Trend tool steel edm lifters.

All the cams looked great after running. They were all broke in with 1.3 rockers, but full spring pressure.
We used Shell rotella with some eos on first ones and I think we had amsoil 30w breakin oil by the last one.

We ran more oil pressure for first dyno sessions, then went to low volume pump and low pressure spring on last day of testing.

Randy

Noticed you had about 45 psi., how much HP gain from the pump change? Did you use a different oil at the same time as the pump change?

77cruiser wrote: ↑Sun Jan 14, 2018 7:18 pm Noticed you had about 45 psi., how much HP gain from the pump change? Did you use a different oil at the same time as the pump change?

It was surprising. If I remember right it was more than any of the oil pan swaps. We weren't expecting anything but there was a little there. Im sure Randy remembers more specifically.

CGT wrote: ↑Sun Jan 14, 2018 8:25 pm

77cruiser wrote: ↑Sun Jan 14, 2018 7:18 pm Noticed you had about 45 psi., how much HP gain from the pump change? Did you use a different oil at the same time as the pump change?

It was surprising. If I remember right it was more than any of the oil pan swaps. We weren't expecting anything but there was a little there. Im sure Randy remembers more specifically.

I always wondered if oil psi made a difference.

There seems to be some kind of weird disconnect between engine builders' experience and the hydraulic industry in general. The internet is rife with formulae such as: http://www.metaris.com/hp-calculator.php for calculating the power requirements of a hydraulic pump. Even with generous assumptions, say 12 GPM flow and 120 psi internal output pressure upstream of the relief valve, the calculated power demand is fractional, yet it is well-accepted in racing circles that small but worthwhile power gains are to be had by minimizing 'excess' capacity...

Provided the pump is not affecting timing some how as it can in ford chev etc there is not much in pump drive hp but a lot in oil viscosity.

MadBill wrote: ↑Sun Jan 14, 2018 9:34 pm There seems to be some kind of weird disconnect between engine builders' experience and the hydraulic industry in general. The internet is rife with formulae such as: http://www.metaris.com/hp-calculator.php for calculating the power requirements of a hydraulic pump. Even with generous assumptions, say 12 GPM flow and 120 psi internal output pressure upstream of the relief valve, the calculated power demand is fractional, yet it is well-accepted in racing circles that small but worthwhile power gains are to be had by minimizing 'excess' capacity...

I have witnessed this contest having 2 points difference between the winner and second place; also .8 of one point difference between 3rd and 4th place; (in the money or no money).

Also, It is not just the oil pressure itself but, more pressure creates more oil "throw-off" in the crankcase from the crankshaft assembly which does consume some flywheel power.
Fractional power demands can be the difference between finishing places here.

Walter R. Malik wrote: ↑Sun Jan 14, 2018 9:58 pm

MadBill wrote: ↑Sun Jan 14, 2018 9:34 pm There seems to be some kind of weird disconnect between engine builders' experience and the hydraulic industry in general. The internet is rife with formulae such as: http://www.metaris.com/hp-calculator.php for calculating the power requirements of a hydraulic pump. Even with generous assumptions, say 12 GPM flow and 120 psi internal output pressure upstream of the relief valve, the calculated power demand is fractional, yet it is well-accepted in racing circles that small but worthwhile power gains are to be had by minimizing 'excess' capacity...

I have witnessed this contest having 2 points difference between the winner and second place; also .8 of one point difference between 3rd and 4th place; (in the money or no money).

Also, It is not just the oil pressure itself but, more pressure creates more oil "throw-off" in the crankcase from the crankshaft assembly which does consume some flywheel power.
Fractional power demands can be the difference between finishing places here.

Ah yes , as far as an EMC point system is concerned you've made a good point there.
I was coming from a 1/4 mile perspective not an EMC one !

I don't remember the exact amount of power gain, but I remember the discussion over lunch about "if" "how much" the gains would be.

It did gain and was enough it was more than margin of error of dyno. I remember one of Joe's customers went to lunch with us and was saying that low volume pump won't gain. He was surprised when we started making pulls after the change.

That whole testing of, thin synthetic vs 15-40 conventional, finding the best of 3 pans, low volume oil pump with a pressure drop from 75 to 45 psi, made a noticeable difference. The combination of all of it was certainly worth some power.

I think Walter is on the right track. Lowering pressure and less volume puts less oil flying around in the crank case. I don't think most of the gains are from power to drive the pump.

I couldn't see any amp difference required to drive a stock pump vs the low volume, when at the same pressure, when I was testing them.

Randy

Would be interesting to see just how low on pressure/flow it could go before 'just' hurting a bearing, then give it a few psi safety margin. If the gains are mainly from less internal oil drag/windage then another 10/15 lb less may worth even more. May also create some expensive shrapnel in the process!!

MadBill wrote: ↑Sun Jan 14, 2018 9:34 pm There seems to be some kind of weird disconnect between engine builders' experience and the hydraulic industry in general. The internet is rife with formulae such as: http://www.metaris.com/hp-calculator.php for calculating the power requirements of a hydraulic pump. Even with generous assumptions, say 12 GPM flow and 120 psi internal output pressure upstream of the relief valve, the calculated power demand is fractional, yet it is well-accepted in racing circles that small but worthwhile power gains are to be had by minimizing 'excess' capacity...

Bill,
When you prime the oil system. What rpm is the drill turning the oil pump with what fraction of a HP?

Stan

My drill I'd guess typically gets ~ 3-400 RPM (6-800 engine) once the pressure comes up and depending on clearances, temperature and viscosity, ~ 20-30 psi. I don't know the range of the resulting flow rates but my S.W.A.G. is it draws <0.10 hp. (I suppose I could use a corded drill and compare amps running free vs. under pressure, assume a number for efficiency and calculate the power demand, but that sounds too much like work!

MadBill wrote: ↑Mon Jan 15, 2018 9:32 am (I suppose I could use a corded drill and compare amps running free vs. under pressure, assume a number for efficiency and calculate the power demand, but that sounds too much like work!

I did the amp meter test on a stock pump vs a low volume pump. Similar pressure between the 2. Stock pump was a few psi more.

I didn't see any amp difference in them. My cordless screw gun took the same setting to drive both pumps.

My less than scientific tests didn't see any difference.

Randy