I am wanting to purchase a set of these oil restricting push rods for my LS6 heads. I have searched on the forum, and have not seen anybody post a part number.
I've checked their catalog, even emailed tech for assistance, and they just sent me the dang catalog if you haven't visited it, there are no engine catagories, etc.... it's just an endless listing of sizes, tips, etc..... i really do not care to "guess" at this purchase. thanks in advance

 

Call Terry Manton of Manton Pushrods. He is very helpful and will answer all your questions directly. He delivers quickly and his products are excellent quality.

 

Why do you want oil restricting push rods?

 

He's likely using a HIPO set of roller lifters and large cam. Some folks swear by them saying that restrictive push rods help keep the lifters pumped up and keep the top end from getting way too much oil which can happen with aggressive ramping cams.

I'm not a fan of them in a street car.

 

i autocross and do some track days. i've had this car for 5 yrs. this 1st cpl years i shelled 2 motors due to low oil pressure. i was recommended by this great forum to use a melling oil pump and an external oil cooler. problem solved but now i have so much oil flow, that it accumulates in the valve train. even with a catch can, after a few big sweepers, oil gets in intake, air cleaner, through exhaust, etc... it's a mess. most of the racers have had to use push rods which restrict some oil flow to the head to eliminate the excessive oiling.

 

too much oil in the heads under hard hard braking has caused several engines to go bang.

 

Folks that have this issue, are they running other than stock lifters?

 

Drilling holes in the lifter guides is another popular way to combat the issue.

Instead of restricting oil to the heads, just allow it to drain back from the heads that much quicker.

 

Link bar lifters is another option.

 

I have had oil issues on the track and am in the process of a fix. I ported out all the oil drains in the heads and smoothed out as much as I could of the head to promote drain back. I also ditched the lifter cups which looks absolutely horrible for drainback and am installing cam motion link bar lifters. Smith bros pushrods as well with .040" hole. This is about as much that I know that can be done to help. Next step is a dry sump oil system.

 

I am finding this thread interesting. Didn't know people were having problems with oil drain back.

Trackboss, I am familiar with the dry sump systems, but I don't quite understand how that would help with head oil drain back unless the real issue is that the engine just plain runs out of oil because the pickup tube in the pan just doesn't have enough oil around it. Under high G forces the oil could be directed everywhere but downward allowing the pickup to suck air. Before restricting oil from high wear (high pressure contact) areas like the valvetrain parts, a dry sump system to me would be best. JMHO

 

YES that is one of the reasons


High speed left hand corners is the other cause.

Most ppl dont brake or repeated brake as hard as in road race / road track applications and why most ppl dont see this. And for the majority of C5 and C6 owners it is not an issue. Well over 1g in braking, from 150-130 down to 70-60 mph for a high speed corner. Doing this 3-5 times every 2 min for 30 to 40 min at a time. 3-4 times a day, for two - three days.

Some times the braking is so hard and in such a short distance that the car "feels like it is" doing a motorcycle stoppie. I run the GM T1 suppension, with 305 tires up front ( great for stopping )

I put a 3 qt accu-sump on my engine back in spring of 04. Best mod I did for my engine. with 25,000 hard 3000 to redline miles, two sets of spring changed, one set of valve changes, M1 15-w50 oil and changing oil every 500 miles, ( two weekends on the track)

springs went from stock to 918s, and 918s a second time. valves remained the same, the stock C5Z valves.

change the 918s the second time do to the recall, but had no issues with the first set. change the valves just because. but no problems with the first set. used 918 springs as my cam has a 581 lift so no need to have too much spring.

 

AU N EGL,

Your regiment of oil and component changes obviously is working. Do you have any oil restricting components like the pushrods or any of the other changes mentioned in some of the earlier postings in this thread?

Have you had any issues with the Accusump system? How much work to install it?

 

Nope just good old normal push rods. Nothing special. They are GM supplied push rods for the LS1, not the LS6. I just made sure they are straight.

the accu-sump and oil cooler was a bit of work. I did not install it. Phoenix Performance west of Philly did the install.

under the left front fender


Trans cooler( left) oil cooler (right) radiator in back and CAI on top.




no oil cooling or coolant problems what so ever Plus lots of air for the CAI

car is a front not a bottom breather ( Z06 screens are duct tape shut for better aerodynamics )



back OP topic

a dry sump is the best option. HOWEVER, they are very expesive. an accu-sump is a good alternative.

for DD, drag racing, or weekend spirited driving just add an extra quart of oil. Change the oil often and send samples to bob the oil guy for analysis. That will tell you what is going on inside your engine.

again I use M1 15-W50 in this vette. but 5-w30 in the street vette. We have two and one under construction

 

The gen 3 gm v8 motors primary oil up top and more oil than needed is pumped up there. Combine that with a shallow oil pan (corvette) very little room for breathing because of the deep skirt block and 6 bolt mains, and road coarse use and the oil stays up top. I believe the modifications that I am doing and listed above will be an improvement. Will have to wait and see.

 

So far no part numbers, contact PUMBA he did smith brothers PR stock z06 with 1.8 crane RR's and 90mm TPIS intake conversion.

 

AU N EGL,

Thanks for sharing the photos of your setup. Very nice! Having higher volume of oil available to the engine seems to be the right direction.

Trackboss,

I'm a little confused with your post, if you don't mind could you elaborate a little more on what factor the deep skirt plays? Also, how has it been gauged that "more oil than needed" is delivered to the upper engine? Is this statement on a stock engine or an engine that has mods, like a higher volume oil pump or other oil system mods?

 

The bottom of the block has small passage ways from front to back so it makes it a bit more restrictive for the motor to breath as the crank is pumping and the crankcase gets pressurzied. More so at high rpm. Old school V8's don't have the problem. Too much oil getting to the top is my assumption and has been covered many times in road race applications. The rotating assembly is what needs the the lubrication the most. Rockers and springs need very little. If you look at a diagram of the oil passage system on the gen3 motors the crank is not primary oiled as in older motors. That contributes to a lot of oil getting up to the heads. Also, if you look at the factory pushrods, the holes in them are quite large. In my opinion the valve train does not need a whole lot of oil to stay cool and lubricated. If its a super high rpm motor that is road raced then oil squirters are plumbed in with custom valve covers to cool the springs and prevent excessive oiling.

 

Oil flow to the valvetrain is directly metered by the lifter assembly. Some of the earlier lifters could flow more oil than current GM lifters. These early units might cause an excess amount to the the upper head area. If you are running current lifters there should be no need for push rod restriction.

It is easy enough to identify problem lifters with excessive metered flow. The valve cover can be removed and laid so the coil to plug wires are still connected and the ground connection kept. Fashion a piece of cardboard to fit between the exhaust side of the head to deflect oil back into the top of the head and away from the exhaust manifold. Start the engine and let idle. Check for oil flow from the rocker where the pushrod rides. It might even take a few second before oil starts to flow. A lifter that is not metering the oil flow properly it will flow out of the pushrod side of the rocker like a fountain. If you have one of these high flow lifters the best course of action would be to replace it.

As far as the hole size of the pushrods, 1/2mm I believe, this again has nothing to do with controlling the oil flow, it is just the messenger carrying what the lifter is metering to it.

I'm not real sure what you mean by “the crank is not primary oiled as in older motors”. The mains are fed by a common gallery. Rod bearings are indirectly fed by the crankshaft from the gallery.

As far as oil squirters, I have seen the type in the LS7 and LS9 for piston cooling, but I haven't seen dedicated squirters for the valvetrain. It's been a number of years since being around the racing arena and things are always changing so I could be missing something.

 

It is true that lifters are the first restriction for oil going up to the valvetrain. I have a '99 so that may be the case, but just about every C5 run hard on the road course over fills the heads.
If you look at the oil system diagram for gen3 vs. older gm v8's you will understand why I say the crank is not primary.
Valvetrain oil misting is far different than what you are referring to. Most all high end race motors (nascar, etc.) do that. Here's an example. Scroll down to part#6832
http://www.moroso.com/catalog/catego...?catcode=37400