Before I ask my question I wanna say thx to all the ppl on this forum been reading it for sometime been a great help so I decided to join

I'm rebuilding a 351m into a 400 and I wana treat the oil issue while I have it out from all I've seen their are 3 ways to this an external oil supply to the starved area , restricters partial or otherwise and a HV oil pump with a larger oil pan which one or combination thereof do y'all recommend thx

 

None. As far as you should be concerened with a hot street motor there is no "oil issue" no "starved area". Get it balanced, chamfer the cranks oil holes, get the block align honed, rods redone with good bolts and set the bearing clearances with a good set of mic's and bore gauge reading in .0001". and it will be fine for what you do. If you set the botom end up right it will last a good long time.

 

I disagree. I've had two 351M's and both have/had poor oil pressure at idle. And Rusty's bearing clearances are essentially new.

So, the 400 I'm building is using Tim Meyer's mods off his web site.

 

Then you did something wrong. I've been building engines for over 30 years and have never had a problem with a 335 series bottom end. As far as built up street motors go there is nothing "wrong with them". How was your align bore ? Was it within .0002" ? Chamfer the oil holes in the crank ? Were the rods resized & within .0002" ? Was it balanced ? Check the crank for runout ? Set the bearing clearances with a bore gauge and mics ? Did you seat the thrust bearing the right way ? You make your own luck in engine building. If you do all of these things "right" you will have a good botom end that will live a good long time, there is no good excuse for loosing a bottom end in a street 335 series. Not to insult you, don't take it the wrong way, everyone starts somewhere. The fact you say you had problems with a street motor tells me you need to learn more, buy more equipment & learn how to use it. Always ask questions, here and there but only from experienced builders. Money doesn't grow on trees and you don't want to be wasting it through ignorance. Good luck with your build. Ask away at Tim he is a good builder and you can learn from him.

 

First, I didn't lose the bottom end. The engines still ran fine, just with low oil pressure at idle and not excellent pressure at other RPM. And, that is a common problem with these engines due to the unusual design of the oiling system.

But, I fully agree with you that Tim is a good builder and I can learn from him. In fact, Tim is considered the 335 Series guru. Which is one reason I've had many conversations on the phone with him. And his strong recommendation for building a 335 series engine is to plug one passage and drill out another in the oiling system, as shown on his web site as well as in my drawing, below, from my thread here: https://www.ford-trucks.com/forums/1...stem-mods.html



So, I strongly disagree with you that the problem is in the way I built the engine. The problem is in the original, and unusual, design of the oiling system. And, not to insult you, when faced with such differing guidance as yours is from Tim's I'll go with the guru's guidance.

 

Gary, I agree that Tim's modification is well thought out and helps with low oil pressure plus improves oiling to the mains.

BUT, the 335 Series engines DO NOT have an unusual oiling system. Take a look at the 385 Series and all Pontiac V8s as those have the same oiling system. AMC V8's are a somewhat mirror image as the oil pump is in the rear and the system oils from back to front. All three of those engine families need tweaks to survive in hot street/racing but you never hear of people claiming those absolutely need modification for normal street use or else those engines will have problems.

I will use Tim's mod on my next street build because it is a very inexpensive mod that does not have a down side BUT careful attention to bearing clearance, lifter clearance, and proper cleaning of the oiling passages have worked just fine on my 335's.

 

I'm not a guru on the 385 Series (I'm not a guru on the 335 series either), but I wasn't aware that it has the same system as the 335's. In fact, I thought there was a crossover between the galleries that run through the lifter bores, which isn't there on the 335's. Given that, on the 335's the oil for the driver's side has to pass the gauge sender, go to the rear main, and then come back up to head forward on the driver's side.

Dad's engine, a factory build, still had good bearing clearance when I pulled it down to make it a 400. And yet it had about 10 psi at hot idle. Rusty's engine, which has very good bearing clearance as I pulled it down to verify when I got it, also has 10+ psi at hot idle. In fact, one of the #5 lifters starts to leak down and tick when it is hot. And, as you can see from the diagram, just because you have 10 psi at the gauge doesn't mean you have any pressure at #5.

So, perhaps "unusual" isn't the right term with which to refer to the 335's oiling system. But, in two out of two of my engines without Tim's mod's the pressure is quite low at idle. So, my belief is that it is wrong to answer a guy that asks what mod's he should make with "None. As far as you should be concerened with a hot street motor there is no "oil issue". For the price of one pipe plug and a little time he can have much better oil pressure than the stock system will give.

 

I don't doubt you for a bit as I have seen 351Ms with low oil pressure at idle....all had a good many miles and I never knew the maintenance history. And I agree that if someone asks what he should do then "nothing" is not a good answer. I look at Tim's mod as cheap insurance so why not add it along with carefully, accurately checking and correcting bearing clearance, lifter clearance, and cleaning out the oil passages....too many guys never run a brush through the oil passages before a rebuild.

I've been told the Cadillac 429/472/500 have the same oiling system as the 335 Series. I've never investigated those motors but I know guys that drag race those make the same mods to the oiling system as the 351C and AMC guys...bushing the lifter bores, running an external oil line, and installing restrictors.

 

I'm sure those things are needed for drag racing, but for the street Tim's mod's are apparently quite adequate. Tim assures me that I want to stay with a stock oil pump and that he sees 40 psi at hot idle time after time with his mod's on a stock pump.

Having said that, I have gone to a few other measures, as I outlined in that thread. I opened up the passage through the oil filter adapter because it was a choke point. And I smoothed the transition from the oil filter adapter to the block's oil passage. Then I used some ball-hones to try and smooth transition from the .585" horizontal bore to the .500" vertical bore. Last, I cleaned up the drain-back holes in the block. All of that is show here. But, I'm not advocating those mod's as necessary. Just something I did to ease the flow of oil.

 

Good work. When I put together my 400fmx in 2004-5, I did similar modifications. I also ran small diameter bore brushes through ALL of the oil passages..chucked into my drill for a little extra help. What I found was that even after boiling the block and then baking it (found too much scale in the water jackets so it went to the oven) I was able to push grime out of the oil passages. My block had a much larger "rough" cast hole in the front of the lifter valley but like you, I cleaned it up with a grinder.

One thing I didn't mention, my new lifters had too much clearance so the bores had to be bushed. I've often wondered if that isn't the source of many 351M/400 low oil pressure problems. I do know my engine runs around 45-50psi at idle and I don't have Tim's kit.

 

That may well be a major source of oil pressure loss since the lifter galleries are used as the main source of oil.

 

thx for your help guys this is the first 335 engine iv rebuilt most of my experience is with dodge mopar engines 318 and the like iv been doing research for a few weeks to try to understand this 351m iv bought to turn into a 400 and the oil issue debate worried me a bit

 

I've been a fan of the "Cleveland" engine for MANY years - for those wonderful canted valve heads, not the oiling system!

The 335 series engine does certainly have oiling issues. The issue is two things really...

1 - it is NOT a "priority main" system

2 - the design of the system relied on tolerances and, just as importantly, quality control that just wasn't there in the 70's

Issue 1 just limits what you can do to correct any deficiencies in the system, item 2 requires a performance builder of these engines to be very diligent about how they are assembled. The REAL fix is to bush the lifter bores, then start controlling the rest of the system. The good news is most engines, and by most I mean 99.5% can get by without bushing the lifter bores. TMeyer has some developed some great methods to do this. Spend a few bucks on his modified cam bearings and his other mods and you'll be just fine.

Even a really good oiling system can be made better, it just depends on the performance requirements. Crank scrapers, windage trays, dry sumps, shielded cam tunnels, valve spring sprayers..... It can get VERY involved for a max effort engine!

 

On my rebuild, I already had my block machined and half assembled when Tim started advertising of his mods.
I would have liked to have done it, but couldn't justify the time or afford the money either. Got his rebuild kit by the way.
BUT, I did polish the valley pan, enlarge the return holes in the valley and not only stripped, cleaned and checked tolerances on a standard oil pump, I put a moroso high pressure relief spring in it as per jack roush(?)
I cant remember exactly off hand and the vehicle has been off the road for a while so I haven't driven it, but it was up over a 100psi when cold initial start up with Castrol 15-40 and zddp (from Tim). It actually popped the oil filter seal. Initially had me pretty worried really.
Once warm I seem to remember it being way up over 50 at idle, but feel free to check my previous posts for more exact comments.
Very happy with it and again, I would've done Tims mods if it was at the shop.
Funny thing is, here in OZ 351C's have god like status and were fitted to some of Ford's legendary race cars of the 70's-80's, and you never read about oil issues.

 

The high pressure spring, external oil line, and restrictors are how racers used to fix the problem with main bearing oil starvation....that and a big oil pan. The problem with a high pressure pump is the stress it puts on the oil pump drive shaft and drive gears (both cam and dizzy). You can wipe out a gear (or both) quickly especially when you add a high lift came with stronger springs. I don't know anyone racing 351Cs anymore, they've either switched to SBC crate motors (due to track rules) or run some type of Clevor built off an aftermarket Windsor block....but even these have oil system mods to live at 7500+ rpm and/or hard cornering.

As for the oil pressure problems on 351Cs, there is some truth to main bearing oiling problems but the majority of the "problems" are issues that any American (or Aussie) V8 has when you begin spinning the motors to 7000+rpm in racing applications. The 351C problems first got (Chevy friendly) magazine attention back in the 1970's when Ford was drag racing and NASCAR racing stock block 351Cs. A stock 351C with mild mods and a realistic rpm range can and do live long lives in daily driven cars. Any Aussie and any American that grew up and street raced 351Cs can attest to that fact. I've been around Clevos my whole life (almost 50 now) and owned, drove, or raced against 400+hp 351Cs that never had a single oiling mod and never had oiling issues.

351M/400 have the same oiling system and I knew a lot of folks that had those in station wagons and trucks and never heard complaints about oil pressure or spun bearings....until the internet age. I have dealt with a few 351Ms with very low oil pressure at idle but as I posted earlier, I didn't know the maintenance history of those motors nor the mileage so it's hard to say what caused the problem. I will stand by the fact that the oiling system on these motors is NOT atypical. The oiling system was designed by Ford to reliably oil and cool the engine for 100,000+miles in day-to-day driving just as GM and AMC designed and implemented almost identical oiling systems for many of their engines and you don't hear people drone on-and-on about oiling issues in those motors under daily driving conditions (hard racing, YES!, just ask a Pontiac or AMC drag racer!)

Once you tear into a 40yr old motor for a rebuild and a little more power, you might as well fix factory compromises and the 335 Series, 385 Series, AMC, and Pontiac motors have mass production compromises engineered into the oiling system. Tim's kit combined with attention to detail during assembly and minor mods (like shown in Gary's thread) will reduce the chances of problems due to the compromises in those engines oiling systems. It makes sense to do these things whether you're dropping $1500 or $10K on a street engine build.