Thread: max oil temp and min oil pressure

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Originally Posted by kitz

I don't understand running the block at 18 psi. Why would it not be evacuated as good as possible? Positve pressures will advance the likelyhood of seal problems and actually reduce oil flow through the bearings. The ambient pressure is a boundary condition for determining flows through the bearings.

Kitz

look at the radiator caps on your cars and trucks they all have a PSI rating on them. the reason for this is I run a jet boat the water is supplied from the pump to the engine. with a properly setup jet pump it will have anywere from 20 to 300 PSI of water pressure feeding the engine. I had a problem with loosing a freeze plug while I was only at 2500 RPM the gage was showing over 60 psi of block pressure. WAY TO MUCH IMO. so its set at 18 PSI now the block runs were I want it to with no hotspots that can be found.

Originally Posted by Fourq

look at the radiator caps on your cars and trucks they all have a PSI rating on them. the reason for this is I run a jet boat the water is supplied from the pump to the engine. with a properly setup jet pump it will have anywere from 20 to 300 PSI of water pressure feeding the engine. I had a problem with loosing a freeze plug while I was only at 2500 RPM the gage was showing over 60 psi of block pressure. WAY TO MUCH IMO. so its set at 18 PSI now the block runs were I want it to with no hotspots that can be found.

Gotcha, I'm sorry, I misunderstood

Kitz

i also agree your cooler should do a better job than it is doing, i know even in my boat (a little 4cyl 180) the oil gets hotter than a firecracker even to the pount that if i had my choice i would run a hi capacity pan to give the engine some thermal room.
a car has a lot of loss of heat just to the air moving by the pan as opposed to the basicly still air in a boat compt.

Smokey Ynuick Say....The correct oil pressure is to have 10 psi for every 1000 RPM.

Originally Posted by Racecar100

Smokey Ynuick Say....The correct oil pressure is to have 10 psi for every 1000 RPM.

I read the same book also about 25 years ago.
A street engine does not need near that much oil pressure so street guys don't get all nervous.
A marine application is a whole other story.
In fact a lot of guys are going the other way on oil pressure in other words they are lowering it to save the dist. gear and make a few more hp.

with the rods in at .002.8 you will have 20psi hot at idle alot of the big blocks i do for race are set up about there . on the rods when the oil get warm it going thru them rods at 002.8 and that is just the way it works .less you run a dry sump .on stock stuff i set them up with 1/2 of the size your running on your rods so the stock oil pump can keep up .i have many big block set up loose and hot they never made 25 psi hot and never more then 65psi running hard and that 10 pounds for every 1000 rpm is bull shit if that was true i would have one big pile of big blocks i do not

Some good info here if you weed threw all the BS..lol

Q, What bearings are you running? You running the H series?I Can't remember.Did you put the 50 wgt in it yet?

Originally Posted by DennyW

Without BS, and H bearings, life would be dull.

i did know a guy that run the uppers on the lowers and the lowers on the top with the H rods bearings that was verry DULL

Originally Posted by Futs

Some good info here if you weed threw all the BS..lol

Q, What bearings are you running? You running the H series?I Can't remember.Did you put the 50 wgt in it yet?

yes I am running the H bearings and no I haven't changed the oil yet . I plan on doing that this week before the drags Saturday night in AHA. you ready to line em up

Originally Posted by Fourq

yes I am running the H bearings and no I haven't changed the oil yet . I plan on doing that this week before the drags Saturday night in AHA. you ready to line em up

YEP Im ready

Cant post pics in here or what?

Originally Posted by pat mccarthy

with the rods in at .002.8 you will have 20psi hot at idle alot of the big blocks i do for race are set up about there . on the rods when the oil get warm it going thru them rods at 002.8 and that is just the way it works .less you run a dry sump .on stock stuff i set them up with 1/2 of the size your running on your rods so the stock oil pump can keep up .i have many big block set up loose and hot they never made 25 psi hot and never more then 65psi running hard and that 10 pounds for every 1000 rpm is bull shit if that was true i would have one big pile of big blocks i do not

OK my question is how do you figure I will have 20 PSI Hot with the rod clearance?

Originally Posted by Fourq

OK my question is how do you figure I will have 20 PSI Hot with the rod clearance?

i have built i enough of them that hot at a idle with a 30w /40w that thats about it .if you have more good ? but thats about it. with no upper end oil restrictors and a m77hv oil pump saying you do not need much more then this and i do not know %100 with yours? is i did not build the engine you have and do not know were the mains are at but if at .003 i could see that it would be 25.

Originally Posted by pat mccarthy

i have built i enough of them that hot at a idle with a 30w /40w that thats about it .if you have more good ? but thats about it. with no upper end oil restrictors and a m77hv oil pump saying you do not need much more then this and i do not know %100 with yours? is i did not build the engine you have and do not know were the mains are at but if at .003 i could see that it would be 25.

Melling 10778C pump with .003 on the mains and no restrictors. ok so that info makes me a little better with the 20 psi @ idle when its hot. I have also heard the 10 psi per 1000 RPM.

well i would hope he is runing H type bearings ???? hope he is