spartyon

I was watching Chop Cut Rebuild on SPEEDTV last night and at the end of the show they explained that a lot of racers tap into an oil passage at the rear of the block, run lines to the valve covers, and inside they ran lines around the top of the covers and drilled little holes so that fresh oil would spit over the rocker arm assembly and essentially cool them off. They explained that this was a little trick that racers used back in the day and how it would help allow the valvetrain to live a little bit longer.

Any one ever done this, seen it done, or have any advice as to how to drill the holes in the line inside the valve cover? I would assume that there is a good method kind of like using a nitrous plate to spray nitrous into a mist.

TA_drag

they used to do that on the old 292 fords due to a top end oiling problem. There was still a few of those dinosaurs around when I first started working on boats in the mid 80s.It appeared to me to be a band aid rather than an improvement. I havent seen it done on any motors since. I have never seen a valvtrain starve for oil on a Chevy unless a pushrod was clogged or everything was very carboned up.

ede

the top of the engine is the last place i'd spend extra time and effort trying to get oil to, at least on a SBC

406TPI

iTrader: (1)

This is a very common practice on race motors...not so much a drag race motor, however, I still have seen it on those too. You are more likely to see it on circle track and road race engines.

grover85

iTrader: (1)

We had special valve covers for the ls1 in our race car. It was totally unsessiary. We actully dont use them anymore.

spartyon

Could you elaborate? I only see this as an improvement with no disadvantages.

Apeiron

The oil supply to the valvetrain is already more than adequate. It's not an improvement if there's no additional benefit for the effort. A common modification with solid roller cams and roller rockers is to reduce the oil flow, not increase it.

83 Crossfire TA

iTrader: (2)

You guys are missing the point… it’s not to improve lubrication, it’s to cool the springs (and rocker ***** if you’re still running them). Yes, plenty of oil gets up there, but that’s after it’s gone through the whole engine and is about as hot as it’s going to get, so it doesn’t do much for cooling, and doesn’t really splash around enough up there to cool either. Heat is the big reason why your super duty, bulky springs come out after a few hard runs with a fraction of the spring rate that they went in with, especially in road race type situations that the engine is run for some time period.

I'd argue that it it actually makes sense in some applications to restrict oil flow to the valve train and then install squirters.

ede

didn't miss the point at all, it still seems foolish to me, if i were to do anything i'd add a cooler to the system.

83 Crossfire TA

iTrader: (2)

Oil would still have to go through the whole engine to get up there, still spray very little oil on the springs, which is where it’s needed, and if you got it cool enough to do any good it would be too cold in the bottom end of the engine…

spartyon

Well, I have some 3/8ths aluminum fuel line laying around and some old valve covers. Should I try it or just not even waste my hour of time making it? It seems like an extremely easy setup to make.

JPrevost

I think it'll do more harm then good on just about any sbc. What would you rather have; "cooler" valve-train and spun rod bearings or a "hotter" valve-train and a running engine?
By tapping into the pressure side you're effectively reducing the pressure and volume of oil that will get to the rest of the motor which includes rod and main bearings. I wouldn't bother unless you've got an extra electric oil pump laying around that you want to utilize.
Yes heat kills springs but if you run your oil temps and coolant temps where they SHOULD be you won't have a problem keeping the springs/rockers/valves alive for a long life.

Vader

You may be able to still buy spring cooler manifolds for rocker covers. Most people used to just fab up their own. They're not much good at straight tracks, but endurance engines might benefit, like in offshore racing or stock cars.

spartyon

So adding an oil cooler to the setup, which I was going to do anyway, will be the best benifit. I just thought I would ask about this topic because it looked very interesting on that show and I wanted to find out more about it.

Vader

Most of the installations that require (or should have) spring cooling manifolds also use a cooler:

avitet

it's used by some prostock racers like warren Johnson and as far as know all the Nextel cup cars run it and if I remember right you can buy valve covers already setup to run oil sprayers it dose increase the life of your valve springs

grover85

iTrader: (1)

You can but it wont be worth it. They are usally made out of aluminum. But are you spinning your motor at 8000 rpm's for 500 miles? Or are you running needle bearings for the cam and rockers?

spartyon

I have some crane gold's going on the motor. It is a 383 with a team g intake, ported iron head with 1.94 intake and 1.6 exhaust (882 castings i think), holley 750, 510 lift cam, and probably a 100-150 shot of nitrous.

grover85

iTrader: (1)

I would just run a oil cooler then. When I had my temp gauge hooked up to my oil cooler in the summer it would never get past 210 degrees.

83 Crossfire TA

iTrader: (2)

I don’t understand what you guys are missing… the last place oil goes is to the valvetrain, so NO MATTER WHAT you do with coolers and other BS the oil will not be an effective coolant for the rocker/spring assemblies because it’s already going to be hot and there is not enough volume directed at the right parts.

If you’re running big valvesprings in an application that will see more then a few minutes of use at a time there is something to be gained here WRT to spring/valvetrain life.

For normal street/strip use, then you're wasting your time

Apeiron

The last place? In a small block chevy?

avitet

i agree that its for the most part not needed but i wouldnt go so far as to say that it is useless all that i was saying in my pervious post is that there are valid uses for them and that they can help extend valvespring life in cases that they are needed like if you do alot of road racing or possible if you open road race other than that i dont think i would worry about it just an added expense for the average street strip motor

JPrevost

I don't think anybody is missing your point but I think you're not understanding that a cooler WILL lower the temps of the oil everywhere in the engine. Just because it gets heated up by the rest off the block doesn't mean that the temp of the oil by the time it reachs the rockers/springs is going to the same temp. It's thermal dynamics. I find the cooler the oil the longer the engine lasts, oil coolers should be a no brainer but often it isn't .

JPrevost

And F1 doesn't use head gaskets (I'm just making a point, don't take it personally).

Apeiron

I'm still trying to figure out how the valvetrain gets oiled last in a stock SBC.

grover85

iTrader: (1)

True I thought the last place to get oil was the oil pressure gauge.

grover85

iTrader: (1)

True I thought the last place to get oil was the oil pressure gauge.

JPrevost

It's not, good eye. The oiling isn't all in series, there is some parallel oiling going on which, when messed with, can effect things down stream. That was my point about adding anything that takes oil volume!
I can't find the sbc engine oil routing diaghram. Anybody have that, please post it, it's great tech data.

Apeiron

<img src="http://216.121.161.76/files/SBCOiling.gif">

askulte

Do it if you want to, but I think it's pointless on an engine that's not built for endurance racing. Very aggressive solid lifter cames have heavy springs that generate a lot of heat at high rpms.

If you don't:
Race at 7000-8500 rpms for 1hr+ at a time
Have an aggressive solid roller cam (generally race only, 5000+ rpm powerband)
Have heavy valve springs

You wouldn't gain from it. You then have oil drainback issues from the head back down to the oilpan. As long as the orifices aren't too large for each spring (guessing .020 or so?), it shouldn't drop oil pressure appreciably. Most folks running valvespring spraybars also run a 20 quart 3-5 stage dry sump oiling system that pulls from each head as well, and puts out quite a bit more oil volume than a stock or HV wetsump pump. Just something to chew on... Yes - heat kills valvesprings, but the spraybars are usually used on engines that need new valvesprings after every race ('Cup), or every few races (TransAm, GrandAm, WC, ALMS, etc), not street cars with hydraulic lifter cams.

grover85

iTrader: (1)

Actully just a note. heavy valve springs are not a good idea. They have done tests on motors with heavy valve springs and they actully can bounce back open and can bend valves.

KillerRS

why not just switch to a dry sump and do it right if you feel the need to add more oil to the valvetrain.

spartyon

Me, personally, I was just interested in this idea. I thought it to be a cheap way of prolonging the life of the valvetraing (primarily rockers and springs). That is why I posted this. Didn't mean to get into any kind of debate. Just wanting to learn a little more. I appreciate all of the comments on here because I did not know that it would have a drastic effect on oil pressure.

askulte

I'm not conviced it actually does have a drastic effect on oil pressure. The Melling M155HV wetsump oilpump apparently pumps 4.5 GPM at idle according to the tech I had on the phone, which is almost a can of soda every second. If ya did it, and saw low oil pressures, then you know it's time to upgrade. To figure out how to do the spraybars correctly, I'd become friends with someone that has a set, and take measurements. Getting the aim right would be important as well. Try it, and if it doesn't work out, ya lost a saturday. No biggie. Not that I think it'd make 100,000 mile valvesprings last 200,000 miles... More like making 1000 mile valvesprings last 1000 miles instead of 100 miles w/o them, but that's beating a dead horse.

JPrevost

I'm not either but here is more wood for the fire. Simple thermodynamics says you need mass flow rate to do any kind of cooling. The higher the rate the more heat energy is transfered away or into the stationary part. So if it is MASS flow rate then you need volume, not just a small mist. For this reason, and the fact that the sbc engine has the mains and rod's oiled last... I'd just worry more about not spinning a rod bearing than trying too cool down the incorrect springs for the job. Having seen what low oil volume (not pressure) can do to an engine I just hate to think what would happen if you removed enough oil volume from the current wet sump system to effectively cool the springs/rockers. You'd have to move about half of that soda can a second considering the surface area of the springs/rockers. Then there's the whole problem with oil being a coolant that I can't get over.

83 Crossfire TA

iTrader: (2)

Tons of people reroute oil turbos and even to oil coolers/external filters without any negative effects, even with stock oil pumps. A lot of engine builders building more serious setups reroute oil to assorted small squirters and other deals (ex, nozzles aimed at the bottoms of pistons to cool them) to cool other components in the engine.

Turbos have a bigger orifices inside them then what we’re talking about here, and although it does take volume to achieve big cooling, the fact is that very little is actually needed to make a difference where there really isn’t much to start with.

For the most part, with a normal oiling system I’d be much more worried about the pump pumping the pan dry, especially with extra oil going to the top of the engine then I would be about the pump running out of capacity to maintain proper flow/pressure to vital engine components, and that is always the case in a race engine, especially with HV pumps, which is the reason why large sump pans and polished/coated oil return passages exist in the automotive world.

That being said, like I’ve already said and agreeing with Andris, I don’t think that there is an advantage in this for the average street engine/drag engine, this is something for big valve springs used for long periods of time…

spartyon

Now here's a question. When I do add my oil cooler, do I also increase the oil amount as well? Wouldn't this solve the if the pan went dry problem? Not to mention that it isn't pouring oil onto the rockers and springs like a garden hose. It is basically spraying them like a nitrous jet. Basically I think it would be creating a restriction if anything. I don't know, I am not an expert on the aspects of liquids other than I need to have them.

JPrevost

A lot of those race engines with valvetrain cooling don't have the mains and rods oiled last in the circuit. They also have large sumps and external coolers. Then there's the whole problem with how they rebuild the engines after every race BECAUSE of the metal to metal contact on the bearings. Every race engine I've ever seen built has used "looser" bearings to accommodate the extra metal temps and the forged parts expanding/twisting etc. In those cases the oil pressure isn't enough and they rebuild the engines every couple seasons. From my perspective I can't think for the life of me why anybody would give their valve springs more worry than their rod bearings no matter what the oil routing. As for turbo's, they don't require much oil, that's the beauty of them! They don't load like a rod/main/cam. Their major issue is axial and vibration. Unbalanced and yes, you would need a lot of oil but not if it was build correctly and maintained.

SERPENT99

if there's a problem with the springs and rockers staying lubed and cooled, this would help, if there's no problem, there's no benefit.

Anyone remember the oiling tabs they had in some valve covers? the suspended oil would collect on the tab and drip right into the rocker piviot. Simple and effective.