cstraub

Your 16qt pan, is in a box style pan or is a sump type pan? If it is a sump style if you can give me the depth of the sump,length, and width I can figure capacity for you. It is always best NOT TO USE 90 DEGREE FITTINGS when plumbing the oil lines. HV pump will work just fine in your application but we like to use a std volume pump and shim it around .125". This puts the pressure around 45 to 50#'s at idle and around 60 to 70#'s at WOT.

Chris

Stef's Performance

articfriends

iTrader: (1)

240 seems awful high for a 550 hp motor with a big cooler.Obviously the mor hp you make the more heat is generated in the oil. What kind of block bypas valves do you have,if you don't have the diesel 30 lb valves maybe they are opening and not all your oil is going thru the cooler,Smitty

articfriends

iTrader: (1)

If your running hydraulic rollers then the first thing to get damaged will be your main bearings if their isn't enough oil film to keep a barrier between them and the crank. Its a bandaid but i would put some 60 wt racing oil in it if you insist on running it with marginal oil pressure,Smitty

REBEL4845

I had an race shop build the motor and dont know what block bypass valves are. The same shop built the same motor 10 yrs ago and it held up fine. I would be interested on how to find out about the bypass valves though. Should I ask the builder or can I find out another way. I thought 240 was high for the cooler that I have now also. I spent about 750 in the cooler and all the replumbing for 20 degrees. Thanks

articfriends

iTrader: (1)

Not sure what block your using but gen 5/6 502 blocks have bypass relief valves on oil filter boss area under the remote block adapter,when people put hi output/high volume oil pumps on they open too easy and some of the oil bypasses the cooler and filter so even though you have a real big cooler some of the oil could be bypassing the cooler. Some people plug the bypas and use a racing filter w/built in bypass(fram hp series/k&N etc) or you get 6.5 turbo diesel bypas valves that open at 30 lbs differential instead of 5-10 lbs like stock ones.You could do this under 50$ in parts,Smitty

Stingray69

Ehhhh, don't Merc marine blocks have the (2) 30 psi check valves?

CcanDo

Does anyone have a baseline GPM volume @70#pressure,220 degrees,BBC?Also,a formula for finding GPM requirements for various orifice sizes,[ex.lifter spray bar,spring oilers,etc.]

Raylar

As an engine guy and a builder, thought I would chime in here. When building any gen 5 or 6 BBC's any good engine builder should knock the oil bypass valves out during the machining and replace them after cleaning during reassembly. If they don't, sometimes a lot of metal can be trapped in the bypass passages and make its way into a fresh motor and do some real damage! Also sometimes, debris can lodge a bypass valve slightly open and cause an oil pressure drop. Another thing to be careful of in marine engine buildup is that when clearances are opened up to the .0025 to .0035 range s that the rod side clearances are held to about .015 to .020 max. The reason for this is that the mains are pressure fed first in the late Gen BBC engines and greater clearances with to wide side clearances will let the pressure push the oil out between the rods and crank journal ends and hence a pressure drop of more than normal. Oil pressure will naturally drop some from overheated oil, 250 to 280 range, but a drop to 10 psi at hot idle is indicating that more than oil temp is the cause here. High volume pumps also tend to drop oil pressure about 15 to 20%, but the higher volume is better for getting rid of heat which is a large part of the oils job. We set our clearances at about .002 mains and .0025 rods and rely on straight round journals and rods to protect the bearings. Most marine motors properly assembled and built will not need clearances above this with the right bearings and oil. I like a pump Melling 10777 or 10778 set 60-70psi @50000rpms loaded, idles @35-45lbs warm @650-750 rpms. Don't overpressure a marine engine oil system, it will push the oil thru to quickly,not allow the oil to remove enough heat from the parts, and increase oil comsumption. Proper oil cooling is a must and the small cooler you are describing here is too small for your horsepower and cubic inch size. Cooler oil will help bring the pressure up slightly but it still sounds like something else here is not quite right. Hope you get everything squared away and the motor keeps purring along.
Just my two cents!

Ray @ Raylar

articfriends

iTrader: (1)

Tech Tip: "Oil Filter & Oil Cooler Bypass Valves"

Excerpt from Speed Reading written by Wade Hajek of GM Performance Parts Gen V and Gen VI big-block crate engines come with two oil pressure bypass valves installed in the engine blocks. Both of these valves are rated at 11 psi pressure differential. One valve is for the oil filter and the other is for the production oil cooler. If you install an aftermarket oil cooler or remote oil filter that attaches to the oil filter pad on the engine block, you should be aware that you need to change the oil filter bypass valve in the engine block. The aftermarket oil lines add resistance which will cause the bypass valve to bypass the aftermarket oil cooler and/or oil filter all the time. Obviously, if the cooler and filter are bypassed the oil will be dirty and hot. Your engine could run hotter and could be damaged by dirt in the oil. If you choose to use an aftermarket cooler or remote oil filter that attaches to the pad, you should change the bypass valve to one with a higher differential pressure rating. A good choice would be GM# 25161284 which is rated at 30 psi. Remove the valve that is closest to the crankshaft and replace it with the new valve. Press the new valve into the engine block and stake it in three places. You should note that the bypass valves don't need to be changed if you use a production oil cooler which uses the production holes in the engine block and you don't use a remote oil filter. Also, if you use an adapter that just angles the filter for clearance you don't need to change the bypass valves.

articfriends

iTrader: (1)

I have read that they do (from other members),i do know if you buy a crate motor it has standard 11 psi valves,i couldn't find anything that says in stone that merc puts 30's in. A buddy of mine cooked a gen 5 502 because of std valves in his boat BUT i don't know the origin of his block,Smitty