Lifter oil restrictors

Does anyone make a kit to reduce the amount of oil to the lifters on our engines ? With a standard flat tappet lifter the galley is closed but when you run the solid roller they have that real skinny portion that lets the oil flow at a higher rate and may reduce the amount of oil to the mains and rods. Is there anything I can do to reduce the volume ? I also start out with 70psi at th back and drop below 50 psi at the front durring the race. I have a 14qt pan and external filter and cooler with cold water running into cooler first. I run full synthetic VV855 20w-50 Valvoline Racing Non Street Leagle oil. The engine is a BBF 513 (.080 and 4.14 and 6.7" rods) fully water jackted with iron heads making a lil over 700hp @ 6200. I have oil returns in front and rear of lifter valley, everything is blended and enlarged on oil entry and return.

BTW - I am running 6 to 8 miles at a time, Comp Jet Circle racing in APBA.

Thanks
Jim

The only way is to install bushings in all the lifter bores, you can only restrict using screw in restrictors for one side.

rmcomprandy wrote:

dfree383 wrote:The only way is to install bushings in all the lifter bores, you can only restrict using screw in restrictors for one side.

AND, when installing lifter bore bushings in a production block the entire main oil gallery should be enlarged, FIRST.

If the correct lifters are used and installed the correct way, there will be little difference in oil delivery to the top between a solid flat tappet and a roller lifter; in fact, because the correct roller lifter is "Edge Orifice" fed, it will usually pass a bit less oil to the top.
Use restricted pushrods if you want to further reduce the oil going to the valve train.

The oil returns from the cylinder heads go directly to the crankcase and the front cover area and not to the lifter valley.

On all my heads and block I have drilled a lil larger than 1/2" and made large funnels in the corners, I have also made the passage fit te head and block so they are actually using the whole hole.

Now can anyone show me what you are talking about ? Where do I get the restrictor ?

You just run a tap in the crossover passage on either side and bottom out a set screw with whatever size hole you want. I have bushed about 30 blocks in the last few years and we put .030" in the bushings and .062" in the crossover. I have enlarged the pass side galley on a couple, but didn't see any difference and quit fooling with it unless the customer wants it. the tap size is either 5/16 or 3/8. I'll have to look at my tooling for that job to make sure.

JR Performance Motorsport wrote:Does anyone make a kit to reduce the amount of oil to the lifters on our engines ? With a standard flat tappet lifter the galley is closed but when you run the solid roller they have that real skinny portion that lets the oil flow at a higher rate and may reduce the amount of oil to the mains and rods. Is there anything I can do to reduce the volume ? I also start out with 70psi at th back and drop below 50 psi at the front durring the race. I have a 14qt pan and external filter and cooler with cold water running into cooler first. I run full synthetic VV855 20w-50 Valvoline Racing Non Street Leagle oil. The engine is a BBF 513 (.080 and 4.14 and 6.7" rods) fully water jackted with iron heads making a lil over 700hp @ 6200. I have oil returns in front and rear of lifter valley, everything is blended and enlarged on oil entry and return.

BTW - I am running 6 to 8 miles at a time, Comp Jet Circle racing in APBA.

Thanks
Jim

The "neck" of the roller lifter body does not reduce the amount of oil to the mains and rods; if anything it enhances the passenger side lifter gallery's oil supply/availability for the mains and rods. Generally speaking, if you want to restrict oil to the top end then I would suggest a combination of Randy Malik and Dave Willingham's suggestions: a lifter valley crossover restrictor combined with restrictor pushrods. Those two changes will limit the top end oiling and might improve your 50 psi oil pressure reading at the end of the race.

Now...that being said...given your severe duty application I will say that starting at 70 psi and still having 50 solid psi after 6-8 miles of WOT 6200 rpm is pretty impressive, and adequate pressure....AND that top end oil restrictors which reduce the oil to cool to your valve springs in your specific application is about the biggest mistake you could possibly make in changing your endurance race engine's oiling system.

Paul