MotorHead

The machine shop suggested that I run oil restrictors in the two oil passages that supply the heads/rockers etc. Does anyone have andy experiece with this?

I also have a 7 qt Moroso pan and Melling 99-HV-S high volume oil pump that he said he would not run. He suggested a SpeedPro pump with the Z28 higher pressure spring. :D

BTW this is for my new 406ci with a solid roller cam.

Pete79L82

My recomendation is not to use restrictors on low RPM motors (under 7000 rpm) With roller cams, the valve springs generate a lot of heat. You use the oil to remove the heat away from the springs. If you use a restrictor then you have to compansate for the lack of cooling oil, such as valve cover spray bars or pressure fed rockers with spring oilers. Restrictors come in .030, .040 or .060 diameter holes. If he insists on restrictors I would use the .060 or even enlarge the hole to .080 to ensure adequate spring cooling.

gkull

I agree with your motor man about the pump. I have something simular

My last 383 lasted nearly two years with .060 back of the block oil restrictors. I partialy blame them for lifter failure. I then drilled out the restricters through the front and side to side with .100 which more than doubles the flow and I still have 70+ pounds hot with 5W-30 or 10W-30 at anything over 3000 rpm

MotorHead

Thanks guys I thnk I will use them but I will drill them out to .100"

This is a street motor that will not see any extended high RPM's and it makes peak power at 6000-6500 RPMs :D

VETDRMS

They aren't in my 406. Did he give a more specific reason why you need them, other then "you do"?

:cheers:

I ended up locking my timing out at 32 degrees, got my idle straightened out and have 15" of vacuum at idle. Response is amazing, it really liked all the extra timing.

MotorHead

His opinion was a solid roller lifter doesn't require a lot of oil ( the rollers themseives get oiled from crank spray ) and the upper parts of the motor ( rocker arms etc ) don't require more than a dribble. He wants to see more oil stay on the rotating assembly ( crank, rods etc. ) Or in other words concentate it on the center of the motor.

I think that is more or less what he said :D

Is your Vette running now, what did yo do about the distributor gear ?


[Modified by MotorHead, 4:25 PM 4/11/2004]


[Modified by MotorHead, 4:28 PM 4/11/2004]

clem zahrobsky

with edge orfice lifters there is no reason to cut back on the oil supply to the top end. the interference fit valve springs need all the oil the can get to cool because of the rubbing action. i have seen dyno tests were the oil was cut off to the top side and using see thru valve covers you could see the exhaust vale springs turn red hot in less than 60 seconds. :chevy

SmokedTires

That sounds about exactly what my engine builder told me too. I have restrictors in mine & will soon see how it works out ;)

Stinger66

My motor man would allways put 3 pipe cleaners in each pushrod of my Super Late Model Stock car motors. He wanted to keep the oil in the pan also. There was still plunty of oil comming up to the rocker and springs but it must of been cut by 50%..

I believe with proper baffles and windage trays and doors in a quality oil pan you can keep the oil you need in the sump and maintain the flow of oil to the top without restrictors or pipe cleaners... Just my opinion :steering:

427Hotrod

Don't use them if you even remotely think you're ever going to be cruising at low speed or idling around. Roller lifters really require a good bit of oil and they actually fail usually because of lack of oil. At low speeds there just isn't enough oil spray to keep them lubed. Trust me ...I've been there!

You can use the newer ISKY or Crowers with the direct pressure pin oiling. Don't use the Comps...junk. They cost much more but should last a lot longer.

Roller lifters have a very restricted oil feed hole to the top end anyway that already cuts lube going up there. No need to restrict further unless you are racing at mega RPM all day.

You can use the HV pump if you have a good sized oil pan. You can also use the HV pump with the mid range Z-28 spring. Biggest thing it will do for you is keep idle and low speed pressures higher. You can use a Z-28 type pump (stock with bigger spring) too. It will work OK, just have a bigger spread between idle and high rpm pressures.

Remember that roller lifters also are a little smaller diameter and by design leak more oil by them.


JIM

gkull

I was out driving my Vette Sunday. I pulled out my 1 inch front spring rubber lower A-Arm spacer to slam my car back down. Then I did an oil change and installed 10w-30 synthetic (Mobile 1)

With my relatively new motor, @2000 miles since refresh and an operating temp of 205 degree water and 230 oil temp. I have 40 psi at my 900 - 950 idle out of gear. 70+ from 3000 on up.

So I think that .100 restricted is OK!

I should also add - To the guy using pipe cleaners - I tried oil restricted push rods before. they just have smaller holes in them. That might be a good idea to keep oil pouring through the wheels. I haven't seen them in years, so I don't know if anybody makes them anymore.


[Modified by gkull, 10:56 AM 4/13/2004]