442 Guatemala

Hi, many of you know in December i just rebuild my 400 engine for my 1966 442. in this time when I start my engine I loose my oil presure and I damage the main bearings, rod bearings and cam bearings.

When I opened the engine I found some problems: Main bearings and Rod bearings clearances wasnt good.

So I start again, I buy new Rod, Main and Cam bearings. I install oil restrictors on mains 2,3,4 I change the oil pump spring to increase the oil pressure. Im using a new stock oil pump and my stock oil pan. (I really dont know the capacity of my oil sotck pan???)

I leave the Main clearances in 0.002, Rod clearances 0.001.

On my cam bearings I have 0.0055 of clearance, is that too much??? thats why im loosing oil pressure???

To help oil return from the heads I drill in each head a new 1/2" holes in the back, and I connect them with a hose to a new holes I made to the block.

Today I star my engine again, I prime my engine first I use 5w 30 oil, then I start the engine and I have like 40psi in Idle, a few seconds later oil presure start going down, to like 25psi, when I accelerate the car I go up to 50psi fo like 10 seconds, 10 seconds later I start loosing presure to 20-25psi.

I talk to Mondello and this guy Linn told me that I need to change my oil pan for a biger one 8 Qts and need a new Hig volume, Hig Presure pump, because im getting out of oil???? Is that a good Idea??

please any help and comments are welcome

thanks

Alex

jensenracing77

you should have 5 Qts of oil in it. it is hard for me to believe that you are starving for oil. Linn is good but i think he may be selling you something you don't need. 25 psi of oil would not bother me. pressure is not necessarily the key. you want oil flow. if you have alot of oil flow you will be good. with high oil pressure you may not have high oil flow. the faster you can bump the oil through, the cooler the barrings will be.

don't know if this helps but i am just rambling.

jensenracing77

after reading again, i think that is around what my car does. i may be a little lower at idle and at operating temps.

joe_padavano

5W-30 is too thin. Your engine should use 10W-40.

geckonz08

shouldn`t his clearances on the mains be .003 and rods .002 ??
mike

88 coupe

What RPM, and for how long?

For a "stock" engine, the manual says .0012" to .0050". .0055" is a bit loose but a high volume pump can easily handle any excess oil flow. If valve spring tensions were increased, clearances would have to be smaller.

Having said that: Consider how those "restrictors" in your 2, 3, and 4 mains, affected the flow to your cam bearings.

It would be possible (with those main/rod clearances) if it was held at over 5000 RPM for several minutes.

Not surprising. He is in business to sell oil pumps, pans, restrictors, etc.

8qt pans with 5 or 6qts, are helpful in controlling windage, but then ground clearance can become an issue.

Correct. You can have all the pressure in the world, but without flow there will be no lubrication. Likewise, you can have all the flow in the world, but without pressure there will be no lubrication.

Norm

88 coupe

Lighter oil will flow through the system easier, and return to the pan in less time.

Yes. For a "performance engine, the rule of thumb: .001" per 1" of journal, or .003" on 1, 2, 3, & 4, and 0025" on the rods, in this case. The exception is .0035" on main #5,

More for a "racing" engine. Less for one that is intended go 300,000 miles or more.

Norm

442 Guatemala

I use 5w 30 just for prime the engine and the first 10 minutes, then I change to a 15w 40. Im using Castrol multigrade

442 Guatemala

[QUOTE=88 coupe;73296]What RPM, and for how long?

I start my engine outside the car, so I dont know thr RPM, I start the car the first time for 10 min with 5w 30, then I change to 15w 40.


For a "stock" engine, the manual says .0012" to .0050". .0055" is a bit loose but a high volume pump can easily handle any excess oil flow. If valve spring tensions were increased, clearances would have to be smaller.

To be exactly for cam clearances I have:
No. 1, 0.004, No. 2. .0.005, No. 3. 0.005, No. 4 0.0055 and No. 5 0.004


Correct. You can have all the pressure in the world, but without flow there will be no lubrication. Likewise, you can have all the flow in the world, but without pressure there will be no lubrication.

as for Oil Flow I think I have good oil flow, because the oil is covering all my valve covers and they are leaking a little bit. What is the minimun oil pressure recomended for the 400 engine?? are you runnig near 25-30psi??

I have some videos when I start my engine, im going to try to uploaded so you can see

88 coupe

The book says 35-45. I would not expect to see that much at a warm idle.

My 425 was about 10 lb @ 700 RPM and just over 50 lb @ 7000.

That will help.

Norm

442 Guatemala

[QUOTE=88 coupe;73308]The book says 35-45. I would not expect to see that much at a warm idle.


My 425 was about 10 lb @ 700 RPM and just over 50 lb @ 7000.

You run on 10lb at 700 RPM without any problem?
Why in the mondello technical manual says that less than 20psi is unsafe and not recomended to be operated?


Norm, can you tell me how to upload a picture or video, I never do that before

thanks

Oldsmaniac

Was the block and crank and rods etc properly machined in the rebuild? Oil pressure will naturally drop as the engine temperature goes up. Did you replace the oil pump again or just shim the spring?.....perhaps the pump is defective. Possibly this drop in pressure is not enough to cause engine damage. I once read a dyno test on the 425 done back in 1965 and they commented on the low oil pressure during the test on a factory new engine however when they disassembled the engine there was no damage to the bearings.

442 Guatemala

Yes the block was properly machined, I double check everithing.

what I dont understand is when I just start the engine I have 40psi, after a few minutes start going down to like 20-25 psi. When I accelerate the car the presure go up to 40 again, but if I keep accelerating the car there is a moment when the presure goes down again. like the pan is empty???

I Dont replace the oil pump, just the spring.

joe_padavano

The oil pressure is always highest when the oil is cold. As it warms up it thins out and pressure drops. As the engine speed increases, pressure usually goes up. If you are seeing a drop after hard acceleration, one of two things may be at fault. First is that you have uncovered the pickup and are sucking air. The second is that the oil level is too high and the crank is whipping the oil to a foam.

442 Guatemala

here are some photos of my engine

88 coupe

It is all relative. At 2000 RPM (under power) 20 lb would be a reasonable minimum to set. At less than 1000 (unloaded) anything over 5 lb would be more than safe.

I have seen this happen with one rebuild. .020" under bearings on a .010" under crank. Bearings were improperly packaged and the "assembler" did not verify the clearances.

In a similar case, pressure was there during cam break in, but went down to 0 after being driven for less than a block. The new pump was DOA.

Put a new high volume pump in it, and remove the "restrictors" so the cam bearings will get enough oil.

Norm

442 Guatemala

A 7 Qt oil pan, and a new Hig volume, Hig pressure oil pump, with new pick'up, will help me to solve the problem? or I need a bigger oil pan like 8 Qt?

442 Guatemala

Hello, today I posted a video in youtube when I show how my oil pressure stay in Idle, and when accelerate the car, goes up, and then goes down again. maybe this video can give you a better Idea on what is happenign to me.

you can go to the link below to see the video.

http://www.youtube.com/watch?v=6lwpS5qhaCU

Today I also call Oldsmobile Performance Products, asking for assistance. The guy asked me what oil filter im using on my car, I say FRAM PH25, he says, FRAM is not a good choice for my car, and maybe that is all the problem, he told me to Change the filter for a WIX or NAPA, is that possible that oil filter can make you loose oil pressure???

thanks for all the comments and advices

Alex

Oldsmaniac

If it were me the first thing I would do was add an extra quart of oil and see what happens.....maybe oil pump pickup is too high on pump.

442 Guatemala

I already ordered from Mondello a new 7 Qt oil pan, new hig volume hig pressure oil pump, and new pick-up. Im going to have it here in Guatemala like in 12 more days.

do you think the 7 Qt pan is enough?

Alex

Oldsmaniac

A 7 quart pan should be more than enough if all is well.....have you tried using a different oil gauge and not so long distance from the engine to the gauge? Is the oil gauge a good quality gauge? Sometimes simple things fix seemingly big problems.

Steve O

When you take the pan off check the bearings. Your clearance is set WAY too tight... It should be .003-.0035 on the mains and .0025-.003 on the rods.

I just had one built with .004/.003 and it runs great with a shimmed HV pump, System 1 filter, Valvoline VR1 20W50 race oil, and 6 1/2 Qts in an 8 Qt pan.

Hot oil pressure is 25 psi at idle and 50 at speed

442 Guatemala

I already check my main # 4 bearing. look very smooth with no damage. im going to attach some pictures.

I have a question if im using to tight clearances what oil should I use?? im using now 15w 40

sledge1545

442 Guatemala

Hi, After all this problems I think I have a good oil pressure again.

What I do to solve the problem is: After Talking to Andy Miller from Oldsmobile Performance Products www.oldsperformanceproducts.com, he recommend the following:

1. I install a new blueprint High volume High Pressure oil pump with a new pick-up
2. I install a new 7 Qt oil pan (I put 6.5 Qts of 15W 40, because of my tight clearances)
3. He told me to change my Fram oil filter for a WIX oil filter. And told me to never use Fram Filters

I buy all the parts from oldsperformanceproducts, they are cheaper than Mondello.

After all this changes now Im having when engine is cold like 55 oil pressure, and when the car is like 200 grades I have 40 psi in Iddle.

I still having a little problem. the first time when I start my engine again with all this new parts, I see a lot of air bubbles in the oil. so I contact Andy Again and he told me that, because Im using ARP main bolts, the oil pump is not sitting good in its place, I have to shim a little bit the oil pump housing. that is the only thing I have to do but I never do that before, so If anyone can give my and advice of what exactly I need to do in the pump I will apreciate thanks

Alex

footbrake

It sure sounds like the pick-up is not positioned right. I had the same problem once and found the pickup actually fell off.