I have been putting together a custom nitrous cam with Crane. It was to be a roller but I was told by people other than Crane that the 3.4 block will not work with a roller cam because of inadequate oil pressure/coverage. Can anyone verify this? Vsixtoy?
Doward?

 

I will be perfectly honest and say I have no clue- I have yet to tear apart the block I have and inspect the stock flow passages. I know the GM aluminum race block has three oil passages bored into it for better oiling at high rpms. I haven't investigated yet what if any it'll take to increase3.4 blocks, or the 2.8/3.1 for that matter also.

 

From what I am reading in the GM power manual, it only talks about inadequate lubrication to the rod bearings on the crank at high rpms. They actually state the the "...CHevorlet V6/60 is remarkably free of any failures caused by inadequate lubrication."

It does talk about inproving the oil pump flow and pressure for racing engines by enlarging the pumps crossover passage AND the pumps pressure bypass passage both to .410".

 

topic

Go to the bottom of the first page. This is where this problem was brought to my attention. What is the link for the v6 60* degree website.
Thanks,
Jim

 

I'm not buying that guys opinion one bit. A roller cam has longer duration and drops off steeper than a hydraulic, but is still less friction. The oil valley is wide open in these block- the guys high as a kite.

 

www.60degreev6.com

Actually, I understand it's supposed to be a problem of 'over oiling' it?

The FWD blocks (roller) have 3 oil passages - the RWD blocks have 2. I'll be comparing the two blocks as time goes on (I've got one of each)

 

How would 'over oiling' be a problem?

 

Doward I 'm sure means cavitating the pump or even blowing seals from too much pressure when the oil is cold on warmups.

Here's a shot of the lifter valley of a 3.4 showing the canals that direct constant flow from the rockers down directly onto the cam lobes and lifters.

 

cool pic

 

Its the best part of this forum. immediate pictures of what is being discussed. Nothing better when showning an example then posting a picture. This is why I have fun on TGO.

 

Ok, so what would be the difference between a solid roller and a solid flat tappet cam involving over oiling. I am already running a solid flat tappet cam in the 3.4 now and I haven't noticed any problems. I guess I don't understand why this would be a problem with just the roller cam.

 

Over oiling a cam is not a problem. The only over oiling problem you can have is cavitating the oil pan and starving the pump because you are pumping it too fastout of the pan back onto the engine. You have this happen and go around a hard corner, the remaining oil in the pan (since low) goes to the side and the puimp runns dry for a second or more- disaster strikes- the engine is no longer being lubricated.

 

Ok, I see. So the roller would flow that much better than the flat tappet. I guess my next questions would be about a larger volume aftermarket oil pan or maybe one w/ baffles. Or would the roller each out flow those mods.

Rookie question time:
If the roller would flow that much more, would that mean that oil pressure would drop?
I have a high volume oil pump on the car now. Would going back to the original oil pump help/hurt the situation?

 

You need a little oiling help that's all.
The oil pan needs a windage tray to keep it in the pan and bafels to make the oil take a longer way to the pick up and allow more time for the bubbles to seperate.
A vaccum pump would help to, it will make the bubbles bigger (less pressure = more gas volume) and float to the top faster.
The worst thing is when the oil gets aerated there is still pressure in the system but by being bubbly it lets friction happen while the driver unknowingly keeps on going.
Get rid of the bubblies and you fix the problem.
The pick up is well covered by oil, a little help will keep it covered.
The key to keeping one of these engines going over 6500rpms is oiling.

 

Thanks guys. You all rock! As someone already said, instant help is awesome and I am totally blown away by the quick, KNOWLEDGEABLE responses. I know in the past, I have been argumentative to say the least but you guys earned my respect tonight.
:hail:

 

Jerriko,

The roller cam is not going to make the oil system flow any more or less than a flat tappet or a hydraulic cam. The system will flow the same.

What we are saying is that if you want to run higher rpms, we suggest you up the volume and pressure of the pump slightly for more flow into the entire system. Now when doing this, you will need a larger oil pan with more volume of oil in it so you are not cavitating the pump. You want the pump to remain entirely under the oil always so the pickup screen does not starve or pick up surface bubbles.

I am currently looking for another 2.8 pan so I can begin to weld in side chambers to increase the pan from 5 quarts to 7 quarts.

Dean

 

I priced one of those pumps (GM part# 10051104) at sbdc2000.com and they wanted $90 for one.
They will ship over here so I can grind it mod it and drill it.
I'm also geting a 3.4L crank to mod soon it will all be on my cardomain site along with the Titanium welding.

 

My understanding (I have not yet seen or tried this myself! So honestly, I don't believe it till I've seen it with my own two eyes! ) is that the FWD roller blocks actually have 3 oil galleys - a main crank feed, and two seperate cam lifter galleys. In teh RWD block, the oil simply feeds into one, and across the block, to feed in the other side. From what I've been told, the problem comes from teh rollers not wanting as much pressure at the lifters? That in order to reduce the pressure, a restrictor would need to be used, but due to the RWD block design, it would starve one side of lifters?

Again, this is NOT MY KNOWLEDGE. MEARLY WHAT I HAVE READ/BEEN TOLD. Obviously, I've got my own FWD roller block, and RWD non-roller block, so I'm going to be comparing the two over the next coming weeks. First, I've got 2 intakes and a set of RWD heads that I'm working over, to sell off, first, to help fund the turbo project.

Oh yeah, on the topic of that - might have a 62-1 lined up for it