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100 psi oil pressure on start-up
Engine is a 428 with roller rockers, morosso oil pump, running Valvoline VR1 engine oil.
Engine previously run on dyno only. Mechanical Smith oil pressure gauge - on start-up gauge climbs to 100 psi in a matter of a few seconds. Is this to be expected using VR-1? Any ideas about the squeeks on the car from video below? First start here- panicked when the gauge got to 100 psi oil pressure (and ofcourse its a 7 litre, not an 8 litre, but I was still in a flap). [ame]https://www.youtube.com/watch?v=weiOfo3sxpQ[/ame] |
When my 428 Cobra Jet was cold and the temps were colder, I would run about 80-90 psi with VR1 and a mechanical gauge. 100 seems a little high. Early on I heard a sound that sounded like the valve lash was too loose. Sounded like lifters. Not quite sure of the squeal, could be the fan belt is loose. I would suggest removing the valve covers and check your lash. Are you running iron heads or aluminum? The valve lash will be different for them cold, as aluminum expands more than iron when hot. After the start-up the valve train should be covered in oil. If not, you may have something blockage an oil passage.
I would try a different oil pressure gauge to rule out a faulty gauge. |
Thanks - I'll check the fan belt - thats an easy possible fix. It has also been suggested to me the water pump may be squeaking as well having been stored dry for a few years.
Engine is running Edelbrock ali heads with roller rockers, and has been run previously on a Dyno about 4 years ago. I had already primed the engine with a drill down the distributor hole and seen oil coming up to the top of the engine on rockers, and as its a re-built engine galleries ought to be clean. |
My rule (and many others) is 10 psi per 1000 rpm.
Considering the engine has already run on a dyno, the oil pressure should already be known? Or maybe not even monitored? The squeak could be something loose, does it change by touching the clutch pedal? Gary |
The squeak almost sounded like a loose side pipe rubbing or something to me.
As for the oil pressure, 100 psi at cold startup isn't going to hurt anything. I don't like oil pressure that high, but the fact of the matter is that when it's good and hot, it will be 20-30 psi lower. Be sure and check the timing. MSD boxes (if that's what you have) can read differently from box to box, so even if the timing was set on the dyno, it could be different now. If it's a hydraulic cam, the chatter you heard at the beginning could be the engine running before the lifters pumped up. |
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Sorry, I should have responded to this - I am running 20W50 Valvoline VR1 mineral oil. Its winter here, so temperatures are zero to 10 degrees C (~32-50 Farenheit) when I get to the garage, so I know that'll make the oil a bit thicker.
Once the fans click on and the engine is pumping out some heat, it goes down to about 70psi at idle (~1000rpm). I should have mentioned its a fully re-built 428, needs firm but comfortable effort on the breaker bar to turn over the engine with the plugs out, so compression is good, but I dont know actual CR ratio, but the engine is 'tight'. Any recommendations? People over this side of the pond all suggest a mineral rather than synthetic or semi-synthetc oil for this kind of old engine. Thinking I should change to 10W40, as I am worried about the strain on the distributor drive on start-up, and weather those big 'W50' molecules are getting into all the places they should. |
10W40 should drop your idle pressure, both hot and cold, but in my part of the world I can't find a listing for 10W40 VR1. 10W30 is listed, and that would probably work just fine, as long as you can maintain 10 PSI / 1,000 RPM (e.g. 30 PSI @ 3,000 RPM, 40 PSI @ 4,000 RPM) and I can't see any reason why not, especially if you now have 70 PSI @ 1,000 RPM with a hot engine.
Personally I would go full synthetic, especially if you're running a roller cam. There are many leery of synthetic, especially with flat tappet cam & lifters - where higher levels of ZDDP are recommended to prevent wiping out lobes. |
428 oil pressure
Assuming they missed high oil pressure on the dyno, sounds like you have the wrong oil pump installed. I had a 428 done a few years ago and during priming my engine guy found oil pressure too high. It turned out we had a 427 pump installed which has a stiffer spring because of the block pressure relief and after swapping in the correct 428 pump everything was fine
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Thanks guys.
I just checked the spec sheet on the internals: Canton "Road Race " baffled oil pan with Melling Hi Vol oil pump, Canton pick up, ARP drive shaft and windage tray. Don't think any of that should cause problems? |
As DXMF said, the relief spring in the oil pump, which opens a valve to dump excess oil back into the oil pan at a PSI determined by the strength of that spring, may for some reason be too strong and not allow that valve to open below 70psi, even in a brand new Mellings (great choice, BTW!).
Perhaps a call to tech support at Mellings could help figure that out and even allow you to get the correct spring to custom set a max psi to suit your engine builder? Just a thought. Cheers! Dugly :cool: |
Thanks....interesting.
A little more internet digging got me this 'A typical Melling high-volume FE oil pump is a gerotor design; a 1/4-inch hex shaft drives it. High-volume pumps typically deliver 20 to 25 percent more oil volume than common replacement oil pumps. They’re not always a necessity, but will raise the oil-pressure reading. Low-idle oil pressure is a common concern with the FE, although it rarely causes any problem with the engine. Melling offers a variety of pumps for the FE, including standard, high-volume, and high-pressure variations.' from here: http://diyford.com/ford-fe-engine-oi...mplete-guide/# Several people have told me they can crank their engine with a breaker bar with the plugs in - that would be almost impossible with my engine, plugs gotta be out for hand cranking. So I am starting to think tight tolerance engine + 20W50 + high volume pump = v high oil pressure. Maybe a call to Melling Tech support then.... |
Kevin,
As you have already discovered from the text in DIYFord (actually lifted out of Barry R's book - How to Build Max Performance Ford FE Engines), Melling offer 3 types of oil pumps. I would suggest you find out if you have a HV or HP pump in your motor. Also, are you running a remote oil filter? Maybe a daft question, but have you connected it the right way round? Where are you taking the oil pressure from? If you are running a flat tappet cam, I would be wary against using a lighter oil. Your 20W50 VR1 is the right weight of oil for that type of cam. I'm running a hydraulic roller cam and I use Joe Gibbs HR oil 15W50. My engine usually runs up to 80psi from cold but then settles to around 40psi at idle (1100rpm). It could be that your motor is still tight and needs running in more? However, not being able to turn it over with a breaker bar (depends how long your bar is?) doesn't sound right to me. |
I've been down this road with my 427 center oiler. It's always had high oil pressure at start up and maintains high pressure (60+) at cruising RPMs even when it's warmed up. I've had 2 Melling HV pumps in it. One when I got the engine and a new one when Keith Craft stroked it for me. It has a Canton road racing pan with a windage tray as well. I also have dual remote oil filters and the block was boiled, tumbled and magnifluxed by Keith before the rebuild. It still starts up around 90 or so after 8,000 miles. Don't worry about it. It's OK. I've used both 20w-50 and 10w-40 Brad Penn in it and saw little difference in oil pressure. These are tough motors so go out and enjoy it.
Tim |
Thanks again or the extra replies.
Barry? - Yes I am running a remote oil filter. You can see the connections here: gently does it.... mind figners - Cobra Club Gallery - I think they are correct. The oil pressure comes from a line plugged in to the remote take off plate, and through to a mechanical oil pressure gauge - wondering if the gauge calibration may be out. Spec wise: I am running a Canton sump, windage tray and Helling High Volume pump (although apparently there are 2 HV variants, not sure which I have). Cam-wise, Lunati hydraulic cam and lifters - Cam: Voodoo 62004 Sharp roller rockers with HD shafts, Comp Cam pushrod Probe forged pistons, Molly rings |
If it were me I'd take the oil pressure reading from the outlet of the remote filter...that way you'll get an accurate reading after the areas of pressure loss across the filter mounting and filter. That would be the pressure your engine actually sees.
Cheers!! Dugly :cool: |
Kevin, "Barry" refers to Barry Robotnik of Survival Motorsports - About Us who's also done much definitive work in publishing data on FEs. You can also find tons of info here: FE Power Forums - Index
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Kevin,
I'm Stuart, not "Barry". I do have one of Barry's engines in my Cobra so there is a link there I guess. Lovehamr was correct in pointing out that I was referring to Barry Rabotnick of Survival Motorsports. I would recommend to get a copy of his book. It contains a lot of useful information on performance FEs. Stuart |
Many thanks,
Kevin |
Kevin I didn't see it mentioned before but with your pressure that high stay away from cheap oil filters. They run the risk of rupturing. Also if you haven't you should upgrade your distributer shaft. I use the ARP shaft which I believe is either 5/16 or 3/8" vs. the stock 1/4". You may also consider the VR1 10-30 weight. I'm no expert but that is what I use based on reading. I think your pump will be able to move a higher volume of oil with less effort. Win win there.
John |
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