20 replies to this topic

[ACJ]

Hi all
I was wondering if anyone can shed some light on oil restriction for 308 ?
I have known this is common with other makes. But lately this topic has come up with 308. One was to put like jet in before the lifter (I cannot see where or how) to have leas oil to the top end. But if you run solid cam you don’t get a lot of oil up there any way ? I have a 308 block apart now and its suppose to have some sort of oil restriction in it but all I can see is the cam bearing cover the holes to the cam. They don’t line up very good about ¼ of a hole is open ?
The other one was drill a hole a the top front of the block under the manifold where the oil feed comes up just under the little walsh plug and run an external line to the 3^rd cam bearing for added oil to the cam for hi RPM?
I have never had any problems with oil feed or pressure before. Maybe a bit concerned about filling the rocker covers with oil but it’s a bit hard to check at full noise. My next billed is going to go a bit harder agene so I was just making sure thanks

[jason365]

FOLLOW LXSS350,S LINK ABOVE THATS MY ENGINE, WE HAVE FULL CONTROL OF HOW MUCH OIL GOES UP TOP AND IT WORKS.

[TerrA LX]

I have a 308 block apart now and its suppose to have some sort of oil restriction in it but all I can see is the cam bearing cover the holes to the cam. They don’t line up very good about ¼ of a hole is open ?

This was an old school builder "trick" to boost oil pressure, the cam bearings are installed slightly rotated to restrict the cam feed holes.

[V-SLR5000-P]

I've heard the story that pipe cleaners in the push rods was the way to resrtrict oil feed to the top end in group C days. Maybe a Les Small tweak. Anyone else heard of this??

[warrenm]

The "pipe cleaner" trick actually works, I used to use this method, twist 2 together then push into the pushrod. Solder works ok, then drill a smaller hole.

[Evan]

I just recently went over my 308 to get more oil pressure and restrict the top end.

Here are the things i did that got me constant 60-70psi at full noise compared to the fluttering 30-40 psi that i had previously that consequently damaged my big end bearings. I didn't not go a full mains priority system like in that thread but just did a few tweaks.

1. Blueprint a standard volume oil pump as per that Aussie V8 thread. Don't be a slow learner like myself and get a system 1 oil filter from rocket ind.
2. Replaced the standard size cam bearings with 0.002in under size. Use one piece bearings instead of the ACL type with the split in them.
3 Hammered roll pins into the center of my push rods to restrict flow to the covers. I can post some to you for $5. PM me.
4. Weld up the 3mm hydraulic lifter breather hole on the cam retainer bolt. Put it back in and mark the side of the bolt that points to the oil pump drive gear and drill a 1mm hole into the center of the bolt. Its still important to lubricate the oil pump gear.
5. Remove and plug the timing chain lubricator. I just put a dob of weld on it.
6. fit a good quality high volume (8 liter minimum) oil pan. The Good ASR pans come with a larger diameter pick up.
7. De-bur and polish the valley.
8. Put large breathers on the rocker covers. Mine are baffled with a about a 2" diameter.
9. Remove the dip stick and run a pipe from the dip stick tube to the rocker covers so it can vent. You can run it to a catch can also.

I think thats it.

Evan.

Edited by Evan, 22 October 2011 - 08:54 AM.

[ACJ]

Thanks for all the good information. But now it just makes me ponder more.
1, so are you saying the 308 feeds the cam oil before the crank or at the same time from the same supply? Because I thought ford was the only motor that feed the cam before the mains?
2, I like the thread from LXSS350 has some very good information there. But I was a bit confused with a couple of things.1, I understand feed the crank its own oil supply and controlling the oil to the rockers. But are you restricting or adding flow to the cam bearings? 2, If the original oil pickup and oil pump have the ability to fill the rocker with oil and suck the sump dry would ant it mean its got good flow? Just off track for a second, did you get this motor dyno in the finish and if so were you happy with its out come? Very nice work and good detail thanks.
So for a street strip car if you could restrict oil before the lifter (or with the lifters) and had most of the oil going to the crank and cam bearing I gather this would be OK. So is this possible with out going to LXSS350 extreme or with out hammering needle roller bearing in your push rods?

Edited by ACJ, 23 October 2011 - 12:45 PM.

[jason365]

just to clear up a few things for you ACJ in my priority mains conversion we feed most of the oil around the back of the cam bearings then down to the mains the cam bearings dont actually see any more oil than ussual.the ability of the oli pump to move the oil isnt the problem its the rest of the oil circuit thats backwards, also filling the covers with oil is a drainback issue caused by small oil returns in the heads and valley the problem is multiplied in stroker and hi rpm engines due to greater crank case pressure caused by blow by.if you look closely on my engine we have fitted external oil returns on the backof the heads.
the engine makes around 400 hp at the wheels and will do ten hard laps of mallala without the oil pressure lights coming on{there set at 30 & 18 psi}in fact the oil pressure rarely drops below 50 psi under power.this used regulary for hillclimbs and circuit sprints but for a steet strip engine a good sump with edge orifice lifters and a good breather setup along with clened up oil returns and polished valley will do the trick.

[jason365]

oldjohno, we must have been typing at hte same time, spot on what you say.
as for pipe cleaners ive used them before a bit crude but they do work.

[ACJ]

So am I right to say for the averages street, strip most of the problem is breathing?
I have the big sump. A crane 288 solid cam, roller top end and happy to go to 7000 on the dyno (last time it was 404RWHP at 6950rpm). I have a high torque power manifold, if I had 2 large breathers in the center of the under part of my manifold and not in the rocker covers and with or with out the edge orifice lifters would this be enough or stupid

[jason365]

try to fit two -16 fiitings for breathers in the valley as you just said but id be using the edge orifice lifters aswell, 7000 rpm is alot and you will need to restrict the top end oil for sure.got a mate with a 550 hp 383 holden who doesnt listen to me and his oil pressure light comes on at the end of a 1/8mile run.its a time bomb waiting to explode but coz i dont charge for my advice it musnt be any good.also 7000 on the dyno is one thing, the sump is in a steady state, you would have very little oil left in it after a couple of pulls if there is no restriction,if the car was accelarating, braking , cornering or a combination of all that low sump level will un mask the pick up for sure.

Edited by jason365, 25 October 2011 - 10:30 AM.