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MOP
08-04-2005, 07:03 AM
What would be considered normal oil usage in a stroker motor? I have real short Lunati pistons with 1/16-1/16-3/16 rings, the oil ring cuts across the piston pin hole. I do have very good oil control from the Lunati Pro Mod crank which throws the oil away from the rods and the Milodon windage tray. I never see any smoke but am using a ½ quart in a little over 100 miles. I noticed this the day I ran out of gas a 1K and have since duplicated it, I run it mostly at 3500 and then some. I am running Kendal GT1 straight 40 but on Kenny (MinxMan) advice will be switching to 20/50 as his testing charts show better protection with 20-50 same brand. I now have 53 hours on the engine and feel the rings should be set.

Phil

Rootsy
08-04-2005, 07:19 AM
We have a Bleeeder! :shocking:

huh sounds vaquely like those 347 ferds with high oil ring locations... do your pistons have the little inserts that go over the pin cutouts to close the gap?

MOP
08-04-2005, 07:40 AM
Yup! A few think the rings may not have set yet, I pulled the plugs they are a real good color with no deposits. No kicks with the way it runs, though am still fooling with the carb lag out of the hole.

Phil

farmer tx
08-05-2005, 12:29 AM
What shape is your engine oil cooler in?

MOP
08-08-2005, 08:52 PM
Mark I had it cleans and pressure checked, it is the two section one for the Merc high perf small blocks back in 85. I have a spare 10" that I may sister up with the exsisting one and use a Tstat to mind the temp. I have not hooked up an oil temp gauge yet, one of my need to do's!

Phil

mphatc
08-08-2005, 09:18 PM
Is your oil getting to temperature? Is this a closed loop cooling system?

Part of the problem is to heavy an oil for break in and to consistant of a running speed. This engine should have been broken in by 10 hours of marine use!
After this many hours with such a heavy oil, I strongly suggest a some run time at a much lower viscosity . . 10w-40 low engine speeds and lots of "hole shots" with lots of throttle and NO high revs, MAX load to force the rings against the cylinderwalls. Keep the revs under 3500-4000, and no rough water running on this thin oil. I also suggest a non detergent oil for this.

Let's hope that there is still some honed texture on the cylinderwalls to seat the rings, and that it hasn't been polished off!

FWIW. my 302 Ford, .020" over has 20 hours in boat use, 8 dyno pulls to 5800 max RPM as break in, never smoked a bit and hasn't used a drop of oil.
I've built 15 race engine since January, none use oil, all were broken in on thin viscosity oils, but to a strict diet on RPMS! 25 years of the same procedure and no blown engines!

Mario

MOP
08-08-2005, 10:51 PM
Mario it is closed cooling ½ system stays rock hard at 180, I started off with Dryedene 10-30 diesel oil and 1 quart of bronze break in stuff. That was recomended by a bud that breaks his blower motors in that way, he says he gets better piston time and ring seal doing that. I ran that mix a little over an hour then went to Kendal GT1 10-30, for the next 5 hours all runs were at varied speeds with hole shots but none over 3800. Since then two more changes both with 40. The first time it hit the 5k range was in the last few days with the new Bravo and over 50 hours on it, the BH loaded the hell out of it the first few hours. The first run with the 28's which was just a few minutes with one hard launch it only turned high 3's, with the 24's it turned low 4's did not break into the upper 4's until I put the 22's on it believe me it has been loaded and launched well above average. I am going to switch to 20-50 on Kenny's advice, he has the charts showing it holds up better then the 40. Oddly I have never seen any smoke what so ever and the plugs look great, I dropped a note off to Randy (BG) he feels that with the short pistons it is pretty normal and not to worry about it. I am going to try a bigger cooler I have on hand, reason is I loose 15-20 psi after a hard run which come back up when I get back down to 34-3500. I still get 70 psi cold start and 60 hot running but like I said it will drop to 40-45 after a long run over 4K Want to hook up my oil temp sender also so I know what the temp is then see where I need to go.

Phil

rayjay
08-09-2005, 01:41 PM
I dropped a note off to Randy (BG) he feels that with the short pistons it is pretty normal and not to worry about it.

Phil

Phil,

With the oil control ring running through the pin's hole, and consequently being unsupported, you're probably looking at having a bit more oil consumption than you expect. It's the price you pay for the long rods and keeping the top ring far enough down from the piston crown that the temperature in the combustion chamber doesn't fry it. Do your pistons have inserts for the pin holes to add (some) support to the ring?

I went through this on a 6" rod 400 I built. Sold it before I ever got a chance to really live with it. I was looking at the pressure build up inside the block and the possibility of running a vacuum pump to evacuate the block. Moroso makes one for the SBC, as I'm sure a number of people do. Supposed to help the engine make more power, but from my experience the extra power comes way up in the RPM range where you are probably not running it.

Might be cheaper just to live with it and let the engine use the additional oil.

Oil cooler might only help a bit with the consumption, especially if you let the oil get to 200degF like you should.

rayjay

MOP
08-09-2005, 06:34 PM
rayjay I have a full Lunati Pro Mod 6" stroker, it does have the ring supports. I think I may not be getting enough oil cooling at high speed, I will hook up my gauge this week. Also grabbed a bunch of 20-50 GT1 today and another super filter, will swap out the oil this week also. I have been picking the brains of the circle track boys, some laugh and say heck they shoot a quart through every race not to worry, I am a ton less concerned about it now that I have gotten good input from so many.

Phil