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Post by 88ss on Jan 30, 2006 2:02:57 GMT -4
Hey Everyone,
I am going to a solid camshaft in my SBC for next year - and I am wondering if I will need to run oil restrictors.
I understand the philosophy of why I should use them, but I can't seem to find any info about the down side if I don't use them. Other than power robbing.
Any advice?
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Post by sam on Feb 5, 2006 9:17:22 GMT -4
With a good quality set of roller rockers you then do not need all the oil up there because you replaced the pivot style rocker which required all the lubrication, also you get rid of the oil running back down over the rotating assembly which in turn robs power, the restrictors helps keep the oil in the oil pan where it should be.The experts say to use because you will gain power.
So as far as I can tell the only disadvantage to not using them is that like you said Rob it is power robbing and just how much power it robs is a good question. ?
Sam
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Post by 88ss on Feb 6, 2006 0:09:21 GMT -4
Hey Sam,
Wow - 109.38MPH - your going to have to get some weight transfer in that lil S10!!
I've got it in my head not to install restrictors because there's a slight chance you could under oil the top end and have some failures you don't want. If it robs 15HP - I still can make it up somewhere else like the oil pan and/or windage tray.
I'll definately be dumping the HV oil pump I was using last year, 90-100 PSI at top RPM is just stupid.
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Post by sam on Feb 6, 2006 8:01:16 GMT -4
That is a lot of pressure , could not of been much oil left in the base. Some years back I learned that a HV pump was not a good thing to use, had one in a sbc with a solid cam and I use to use it and after one summers use I took it apart to change the heads and camshaft so I decided to have a peak in the base, low and behold it had scuffed the bearings.
A good friend told me that a good quality stock style pump is all that you need and true to the word so far I haven't had any troubles sense .
And you are right Rob, some weight transfer wouldn't hurt in the S10, coil overs and a ladder bar setup might be in it's future. 60 foot's are 1.96's to 2.10's range.
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Post by Road Rage Racing on Feb 6, 2006 23:37:57 GMT -4
HV pumps are something most people think they MUST HAVE for some reason. Like Sam said, all you really need a quality stock type pump.
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Post by Site Admin on Feb 11, 2006 15:45:20 GMT -4
Sam is correct, HV pumps do not belong in high reving race engines. It is counterproductive to install restrictors then a HV pump. Oil pressure, not volume, keeps the crankshaft bearings in their desired position as opposed to the base pan or the ashphalt.
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Post by 88ss on Feb 12, 2006 17:04:57 GMT -4
Yeah - I've learned (the hard way of course) that HV wasn't the way to go. Had it in my head to run a fairly stock motor and use a light weight oil with the hi volume - didn't work as expected.
Have you used oil restrictors with solid lifter/roller rocker combo? Or better yet - did you run that combo without and had any complaints? This is Gary Keans right?
Rob
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Post by sam on Feb 12, 2006 19:50:59 GMT -4
The person that made the post is our track director (I hope I got his title right).... anyway it is the gentleman that runs around on the red scooter with the headset on. ;D ;D ;D
Sam
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Post by Site Admin on Feb 12, 2006 22:40:40 GMT -4
For a number of years I have used restrictors, solid lifters, roller gear, standard volume pump, no valley plugs or screens and have never had a failure due to oiling problems @ 8500 RPM
It depends what RPM you are going to turn the engine as to whether you may want to use them or not.
If your max RPM is fairly low then you may not need them.
The solid lifters need oil only for lubrication of the camshaft end and the block, not to keep the lifter full. At higher RPM's Restrictors allow plenty of oil for the upper end as well as can increase pressure to the lower end where you need it.
Without restrictors at high RPM you can put far more oil up top than is required which robs HP and more importantly you can easily empty the base pan. Add a high volume pump to that and you can have most of the base oil in the lifter valley at the end of the run. Some add lifter valley drain back plugs and a screen on the front drain but that just ensures that nearly all the oil remains on top and starves the lower bits at the end of the run while under hard braking.
Hope this helps.
Mitch
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Post by 88ss on Feb 13, 2006 13:51:43 GMT -4
Thanks Mitch - that's exactly what I was looking for. I'll probably be spinning it to 7-7500 on the high end. As my bottom end is stock (I'm not saying this is intelligent!!) I never thought that there could come a point that I could empty the oil pan. Are solid lifters any more of a restriction to oil flow than hydralic lifters?
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Post by Site Admin on Feb 14, 2006 0:32:38 GMT -4
Not much, once the lifter is full it does not use much oil. They both oil the pushrods and rockers. As far as emptying the base, that's one reason people use an oil accumulator. I use a quality Moroso 8 quart trap door pan, 2 quart automatic accusup, 10 1/2 quarts of oil and I can still make the 15 LB light flicker on braking if I try real hard after an 8500 RPM run. Just another tid bit of info, the oil pressure gauge still shows 40 or so lbs when the 15 lb light is flickering because the gauge has a restrictor to prevent massive oil loss in the event of a line breakage so the thing lies. You can have 0 pressure long enough to destroy a crank before the gauge will drop but the light is near instant.
I therefore use the gauge to see the actual pressure before the run then use the light only during and after the run.
Aren't I just a wealth of useless information...............LOL
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Post by Bad Influence on Feb 15, 2006 15:33:49 GMT -4
Well I'd say that was a great bit of useful info.I have the same problem under braking myself. I went to the 2nd race this year and I lost oil pressure on the braking; only I had the light on and the gauge on 0 psi. I drove it a ways and then shut it down. It took a long time for the oil to run back; when I drained it out I had 9 quarts, so it goes to show that the accumulator does a great job there.
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Post by ChipperChapman1090 on Apr 2, 2006 19:40:10 GMT -4
On a typical SBC with a stock 5 quart system and a good stock style pump, at 6000 rpm there is 3 quarts in the top of the motor, almost 1 in the filter and only one left in the pan. I beleive I read this in CHP, but will never forget it.
I was running 15W40 in the Camaro and had troubles with the pressure dropping about 50 feet before the traps, as soon as I would hit the brakes it would start coming back. Switched to 10w30 so it would hopefully drain back to the pan quicker and it it cured the problem, so I assume the lighter oil does drain back a fair amount quicker. Something to consider.
Also, I've been spinning this thing 7000 through the traps with the stock pan and pump, but a Canton 'Big Block' spring in the pump.
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