Oil Pressure???

[CMC17]

Not sure how much is too much.

With the old motor I was seeing 60psi at startup and around 40psi after a race.
With the new(er) motor installed, I'm seeing 80psi at startup and 100psi if I rev the motor. Doesn't too much pressure froth the oil?

...off to the dyno this week.

[mitchntx]

100psi!!!!

You'll wash the babbit out of the bearings ....

[donovan]

60 - 40 is pretty normal...

80-100 WOW!

I don't know what that will do... :?:

[CMC17]

It's got me baffled too!

I used the same oil pump (2yrs old) that came out of CMC17's old motor. I did notice that the gasket where the oil pump mates with the block had a small tear/hole on one side of it. I made sure when I installed it in the new motor that it was sealed properly.

:shock:

[marshall_mosty]

Eric,
I'm surprised you have an oil pressure gage. :)

Honestly, I have no idea about the oil pressure. The only thing I would worry about is blowing out one of the oil gallery plugs (ask Michael about that one).

Also, the higher pressure obviously takes more HP to generate, but you know that already. 8)

My car sees 50 psi pretty much all the time. That's with my electric AutoMeter gage.

[donovan]

It could be clearance issues causing the high presure... maybe the oil passages are smaller or the passages are tighter than the previous engine.

[CMC17]

I blacked out the gauge from 40-100. If I see the needle fall below 40, them I'm in trouble, otherwise everything is going to be ok. lol

:shock:

Lets see how it does on the dyno this week. I'm calling ahead for a mop and bucket.

[oz98cobra]

If it was a Ford mod motor, those pressures would not be alarming, but for a 5.0? That's waaay up there! Sure you didn't fill the crankcase with gear oil by mistake? ;)

[CMC17]

If it was a Ford mod motor, those pressures would not be alarming, but for a 5.0? That's waaay up there! Sure you didn't fill the crankcase with gear oil by mistake? ;)

I thought about going with a lighter oil once I saw the oil pressure.

Current oil: Royal Purple 20w/50 (6qts)

http://www.tek-racing.net/cmc17/ItLivesCMC17.mpg

[oz98cobra]

related Corner Carvers post with some possibly useful info:

http://forums.corner-carvers.com/archive/index.php/t-3319.html

[CMC17]

related Corner Carvers post with some possibly useful info:

http://forums.corner-carvers.com/archive/index.php/t-3319.html

Thx Daron!!!

At least I only have 80psi at startup and no 100psi like that guy did! lol I will probably switch to a thinner oil first to see if I can get it to drop 10-20psi.

[jeffburch]

If it was a Ford mod motor, those pressures would not be alarming, but for a 5.0? That's waaay up there! Sure you didn't fill the crankcase with gear oil by mistake? ;)

I thought about going with a lighter oil once I saw the oil pressure.

Current oil: Royal Purple 20w/50 (6qts)

http://www.tek-racing.net/cmc17/ItLivesCMC17.mpg

Uuuuh, does that vid have any sound?

jb

[CMC17]

If it was a Ford mod motor, those pressures would not be alarming, but for a 5.0? That's waaay up there! Sure you didn't fill the crankcase with gear oil by mistake? ;)

I thought about going with a lighter oil once I saw the oil pressure.

Current oil: Royal Purple 20w/50 (6qts)

http://www.tek-racing.net/cmc17/ItLivesCMC17.mpg

Uuuuh, does that vid have any sound?

jb

It should.. but only one channel for some reason. Try the Left or Right..won't be on both.

[AI#97]

If it was a Ford mod motor, those pressures would not be alarming, but for a 5.0? That's waaay up there! Sure you didn't fill the crankcase with gear oil by mistake? ;)

Yep! When my motor was new it would hover around 100psi at idle cold, then settle down to 70 at idle and 90 during a race. that was with 10-40 oil!!!

Now with three events on it, it is at 75 cold at idle, then settles into about 50 with warm oil and about 70-80 during the race.

That much pressure in a 5.0 tells me you have a tight engine that is going to free up power at some point when it loosens up. Be careful. You may also have issues with lifters coming apart and the oil galley plugs as Marshall mentioned. If it were me, I would be worrying about too much pressure and not enough oil flow.....go to a good 5-30 oil and see how it does. Once the clearances free up, then you can step up the oil weight....

[gt40]

(I haven't read the CC thread yet, so this may be covered there -- I dunno yet...)

I'm having trouble understanding how the same pump can generate such high oil pressure in a different motor.

As I understand it, there's a bypass port in the pump itself. It's spring-loaded and set to start bypassing oil once the pressure hits a certain point (70-80 PSI for a normal pump, somewhat higher for a high-pressure pump.)

Is this pump a regular or a high-pressure pump?

[jeffburch]

[quote=oz98cobra]If it was a Ford mod motor, those pressures would not be alarming, but for a 5.0? That's waaay up there! Sure you didn't fill the crankcase with gear oil by mistake? ;)

I thought about going with a lighter oil once I saw the oil pressure.

Current oil: Royal Purple 20w/50 (6qts)

http://www.tek-racing.net/cmc17/ItLivesCMC17.mpg

Uuuuh, does that vid have any sound?

jb

Weird computer issue on my end.
WinDVD, no sound.
WinMedPlr, no play.
Divx player, right ch. good.

Sounds great!



jb

[CMC17]

[quote=oz98cobra]If it was a Ford mod motor, those pressures would not be alarming, but for a 5.0? That's waaay up there! Sure you didn't fill the crankcase with gear oil by mistake? ;)

I thought about going with a lighter oil once I saw the oil pressure.

Current oil: Royal Purple 20w/50 (6qts)

http://www.tek-racing.net/cmc17/ItLivesCMC17.mpg

Uuuuh, does that vid have any sound?

jb

Weird computer issue on my end.
WinDVD, no sound.
WinMedPlr, no play.
Divx player, right ch. good.

Sounds great!

jb

Cool!!

I should have posted this one instead.

http://www.tek-racing.net/cmc17/ItLivesCMC17.wmv (Windows Media/2.5meg)

[CMC17]

(I haven't read the CC thread yet, so this may be covered there -- I dunno yet...)

I'm having trouble understanding how the same pump can generate such high oil pressure in a different motor.

As I understand it, there's a bypass port in the pump itself. It's spring-loaded and set to start bypassing oil once the pressure hits a certain point (70-80 PSI for a normal pump, somewhat higher for a high-pressure pump.)

Is this pump a regular or a high-pressure pump?

It's a fairly new pump (Melling HP). I think one of the reasons for low pressure on my other motor was the gasket where the pump meets the block had a tear in it. I'm sure it had to be sucking some air. The gauge would bounce around during a race. The newer motor has 79k on it. The rebuild was done at 77k. 2k on the rebuild and they guy I bought it from didn't know the clearance numbers..etc. It was done by a reputable shop and all looked good when I lugged it home.

Changing oil this evening to see if I can get it to drop some psi. Wish me luck. =)

[BSharp]

If it is a Melling HV or HP, those #'s are where it should be. On a cold fresh motor 70-80 at idle is normal.

[marshall_mosty]

**Edited to remove the reference to Eric not having an oil cooler... my bad.**

[CMC17]

We're lucky that Eric doesn't run an oil cooler.... or he would blow a line and slick down the track, right Michael??

I don't? :shock:

Everyone stay well behind me....just incase!

[marshall_mosty]

Nevermind... I guess I'm confusing that with an oil temp gage... right??

[gt40]

It's a fairly new pump (Melling HP).OK, first off, almost every engine builder I've talked to says unless you have a specific reason for running a high-pressure or high-volume pump, stick with standard, blueprinted pumps.

On my car, with a plain-jane Melling pump cold idle pressure is 70psi (right where the relief valve is supposed to be set for.)

Hot idle (after a race,) is 20psi running fresh Mobil1 20w50. (I've no idea what the oil temps are -- I'm afraid to install a gauge!) ;)



I think one of the reasons for low pressure on my other motor was the gasket where the pump meets the block had a tear in it. I'm sure it had to be sucking some air.If its where the pump meets the block, you'd be pissing oil -- and probably were. Not a good thing from a aeration standpoint.


The gauge would bounce around during a race. The newer motor has 79k on it. The rebuild was done at 77k. 2k on the rebuild and they guy I bought it from didn't know the clearance numbers..etc. It was done by a reputable shop and all looked good when I lugged it home.It probably has production/street bearing clearances in it, meaning it'll have higher oil pressure than a worn engine or one built with looser clearances for racing. Bud's correct -- your numbers look OK for a fress motor with production clearances and a HP pump.


Changing oil this evening to see if I can get it to drop some psi. Wish me luck. =)My money says you won't. Bite the bullet and put in a standard pump.

[David Love AI27]

I think one of the reasons for low pressure on my other motor was the gasket where the pump meets the block had a tear in it. The gauge would bounce around during a race. The newer motor has 79k on it. The rebuild was done at 77k. 2k on the rebuild and they guy I bought it from didn't know the clearance numbers..etc.

Since you seem a little unsure, I suggest keeping the revs under 3,000 for the rest of the year till you are sure of the required breakin period for the motor. Maybe three or four weekends to get a good 1,000 miles under your belt. Then you might try bumping it up to 4,000 RPM in practice but not during races in case the motor blows. By the start of the 2007 season I'm sure the motor will be ready for full race mode. Just a suggestion...

[CMC17]

5psi difference at idle with:

Royal Purple 20w/50 - 80psi
Mobil 1 5w/30 - 75psi

After the dyno pulls, 70psi at idle. No explosions.... yet. 8)

[michaelmosty]

After the dyno pulls 8)

and the results....... :lol:

[Todd Covini]

Well at least it's good to see that you've come to your senses and put Mobil 1 in there.

However, even idling at 75 psi...you won't last the weekend. The motor will likely give up the ghost at the most opportune time. Don't worry about it though. Try not to think too much about it when your rearview mirror keeps flashing "MOBIL 1" from side to side at you. :twisted:

I'm sure it's just that little piece of gasket.
Just put it out of your mind.
No worries.
Nope. ;-)

-=- Todd

[jeffburch]

Well at least it's good to see that you've come to your senses and put Mobil 1 in there.

However, even idling at 75 psi...you won't last the weekend. The motor will likely give up the ghost at the most opportune time. Don't worry about it though. Try not to think too much about it when your rearview mirror keeps flashing "MOBIL 1" from side to side at you. :twisted:

I'm sure it's just that little piece of gasket.
Just put it out of your mind.
No worries.
Nope. ;-)

-=- Todd

:lol:

jb

[CMC17]

Well at least it's good to see that you've come to your senses and put Mobil 1 in there.

However, even idling at 75 psi...you won't last the weekend. The motor will likely give up the ghost at the most opportune time. Don't worry about it though. Try not to think too much about it when your rearview mirror keeps flashing "MOBIL 1" from side to side at you. :twisted:

I'm sure it's just that little piece of gasket.
Just put it out of your mind.
No worries.
Nope. ;-)

-=- Todd

If you can't beat 'em, might as well buy stock in them and user their product (Mobil 1). lol!!!

The engine is sooooo smooth. I stood a nickel on end on top of the upper intake and it never fell over at idle. I couldn't help but rub my hands together, arch my back and scream like Dr. Frankenstein.. "IT'S AAAALLLLLIIIIIVVVVEEEE"... muaahaahahahaha.

Ok, back to reality. The $75 shortblock my give up the ghost during practice and I will be screaming something else.

Here's to some good racing this coming weekend. :toast: