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I have just been told by someone who sometimes knows what he is talking about that if you are running synthetic oil (especially in a racing engine) you need to tighten up the clearances in the oil pump. Has anyone done this? Is it necessary?
Thanks..
 

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It's not the pump that's the problem. The factory engine clearances are not built around synthetic use. That said, there are a couple of synthetics that might work for you. One is Mobile 1.
Here is where you will run into problems. Race engines generally run a little more clearance on rod and main journals. This can combine with non restricted galleries to the head, and sometimes generous cam bearing clearances to not only pool oil in the head, but exceed the pumps volume capabilities at high rpm.
When the above is combines with SOME synthetic oils that may gain viscosity when heated, you end up with pump gear loading issues with straight cut (2L ) pump gears at high rpm. The pump main shaft will break at the pin through the drive gear, or in some cases, where the shaft diameter is reduced just above the pump driving gear.
For my racing customers, synthetic is a false economy. Very few synthetics include enough zinc additives for these flat tappet engines. Redline offers an additive that can be added to synthetic oils, but you will still suffer viscosity and gear loading issues.

Correctly built Alfa pumps have minimal tolerances to begin with. With some of the pure racing pumps I build, the radial gear clearances are increased, not decreased, to reduce gear loading at high rpm. In this case is is low engine speed volume that may become an issue.
The total amount of oil an Alfa pump can deliver, helical or straight cut gear pumps, is limited by the size of the gears in that pump. At some point, with engine speeds and engine clearances, Alfa pumps loose ability to deliver required volumes of oil, and pressures will drop. If the type of oil conspires against the pumps ability to run fast, (gear loading) you have pump failures. Combine this issue with generous engine clearances, and your engine build is not correct for synthetic use.
ALL the above is my opinion from my experiences with Alfa engines and Alfa oil pumps.
Yes, I have tried dry sump systems, but that is another issue.
 

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For my racing customers, synthetic is a false economy. Very few synthetics include enough zinc additives for these flat tappet engines. Redline offers an additive that can be added to synthetic oils, but you will still suffer viscosity and gear loading issues.
Pardon me for straying off topic a bit, Gordon, but are Alfa engines really the same as flat tappet, pushrod driver engines? I ask because I did a little internet digging the other day and came across a tech description on one of the hot rod magazines (can't remember which, maybe Hot Rod) which specificall stated that overhand cam engines with bucket cam followers don't have the same requirement for high ZDDP that flat tappet motors do. Now I'm confused. :)
 

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The problem is the cam lobe on a flat tappet or follower. Push rods and rocker arms don't count. My Briggs & Stratton log splitter engine is an "L" head design, with flat tappets. Roller lifters ("roller-cams") are exempt. Old Ferrari single cam v12's with roller rockers are almost exempt, except for the tiny adjuster that contacts the valve stem tip. It acts like a flat tappet, and you will end up with metal transfer pits on the adjuster tip, or worse, the valve stem tip even with ZDDP!
There are some excellent articles here on the BB about the necessity for ZDDP additives in oil for Alfa engines. The material acts like a high pressure lubricant as the cam lobes move over the follower and the molecular oil is essentially swept away, (simplified) leaving the follower with no oil cushion. This will give you Alfa followers that look like this, and ruined cams as well.
 

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Hi, Gordon. I read all the ZDDP comments here (most of 'em) but I was still curious about the whole issue. I found two separate tech articles from apparently reputable sites which specifically mentioned that twin-cam engine with cam buckets did not need the highe levels of ZDDP required for "flat-tappet" engines. Now don't shoot the messinger, I'm just a simple cipher here! I'll dig around and see if I can find the tech articles again.

In the meantime I found an interesting factoid which may render the whole issue more academic than practical. I found this communcation from STP regarding the amounts of ZDDP in their additives on a Chevelle website. The simple solution for Alfa owners is to just buy a can of STP and add at oil changes. You can buy it anywhere and it's cheap insurance.

Dear Mr. Wheaton,
Thank you for contacting us about STP Oil Treatment - 4-Cylinder. We always appreciate hearing from our consumers.

Unfortunately, the amount of ZDDP in both types of oil treatments is proprietary information. However, I can tell you that the red bottle only contains slightly more than the blue bottle. Both products contain about 4 times the amount of what motor oils once contained. I hope this information helps you.
Again, thank you for contacting us.
Patti Copper
Consumer Response Representative
Consumer Services


And now, back to oil-pumps . . .
 

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Unfortunately, the amount of ZDDP in both types of oil treatments is proprietary information. .
Proprietary? Seriously? Would it be that hard for a lab to measure it?
 

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I'll still go with the Red Line stuff in the little bottle if I'm unsure. The diesel engine oils contain plenty. Most of the non detergent racing oils contain plenty. Most of the stationary engine (generators, pumps LOG SPLITTER) oils contain plenty.
With Alfa engines, the damage shown to the followers was all in one engine, I don't ever need to deal with that wit expensive cams in a good engine. I'll stay with oils with plenty of ZDDP!
 

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The flat tappet issue applies to all kinds of different engines, whether OHC, pushrod, what have you. I get Crane Cam zinc additive from Summit Racing, and Brad Penn oil has proper zinc in it too for flat-tappet engines.
Last valve adjustment on my GTV in summer 2010, it had one ruined tappet and cam lobe. When one's ruined, pretty much so is the other; they work together.
Andrew
 

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Back to the oil pump, that got me to thinking that if loading can break and oil pump shaft because clearances are to tight what is the relief valve doing in all of this? Is the piston or ball off it's seat and even then is there so much capacity the gears load the shaft to breakage? Then it would seem to me the bottle neck would be in the relief port? Did Alfa go to straight gears because of cost or is there another reason? just thinking out loud here hoping I might learn something.
 

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Proprietary? Seriously? Would it be that hard for a lab to measure it?
Somebody did, apparently. From the 'net: STP red bottle 2100ppm appx.,
blue bottle, 1700ppm appx. Blue bottle is $2.99 @ Advance Auto Parts.
 

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Correctly built Alfa pumps have minimal tolerances to begin with. With some of the pure racing pumps I build, the radial gear clearances are increased, not decreased, to reduce gear loading at high rpm. In this case is is low engine speed volume that may become an issue.
Back to oil pumps.

I noticed, Gordon, that Classic Alfa in the UK is selling new oem quality pumps, but they're expensive. For me this raises another question: is it possible/cost effective to refurbish existing Alfa 105 oil pumps (I have several laying around here)? What would make an oil pump unusable for rebuilding? Can you safely mix early pumps w/late motors or late pumps w/ early motors?
 

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Good thinking! With a good pump, the relief valve will be in motion ALL THE TIME. It is regulating pressure (volume) against engine clearance resistance. At high engine speeds, 7500 or so, there is usually a drop in pressure. If the pump is good, and the engine is good, the relief valve will be (possibly) seated. At this point, the volume the gears can deliver cannot overcome the loss from the quickly spinning bearings. It is as if the bearing area has grown larger, and the pump volume can no longer cover this larger area with the same thickness of oil film.
Pictured below are two photos of straight cut gears in a normal relationship. Note the depth of the gear from the top of the tooth to the root in the valley. Alfa needed to maintain gear wall thickness in the root, so to make it as deep as possible and maintain wall thickness for strength from this root to the shaft, they reduced the main shaft diameter where it passes through the gear. Now compare these photos to the helical cut gears in a lower body, and the difference in the depth of the gears becomes more apparent. The volume of oil carried in a tooth groove with the straight cut gear is greater than that of the helical grooved gear. The purpose was to carry more volume at lower engine speeds.
However, when the pump with straight cut gears is run really fast, though it may deliver more volume than the helical pump, the trade off is the load on the reduced diameter shaft used with the straight cut gears. If the radial clearance is opened up between the straight cut gear and lower body bore walls, this load may be reduced, but so is the volume capability of the pump. To simplify, the helical geared pump does better with high speed engine applications, and the straight cut geared pump does better with low speed engine applications. There are tricks than can be applied to either pump so they can be used in the opposite applications, but that is another issue.
I hope this helps.
 

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Jim. Yes. My business is using core (used) pump components, to remanufacture special purpose oil pumps for both street and racing use, or about anything in between. I usually have a serious discussion with customers about the real use of the pump they think they need, then educate them as to options and the reasons for the differences in both pump type and useful applications. If any of my customers are reading this, they might chime in to discuss the questions and answers I field, along with build photographs, so they get exactly the pump they need. I am fortunate in having built pumps for customers all over the world. I like my customers, and do not build generic, one type-fits-all pumps. The costs for custom pumps vary with application. Some take a lot of time to build, others require hard to locate components, or extensive machine shop time.
As far as mixing pump and engine types, I am currently building a helical geared pump for a customer in G.B. for his injected 2 L race engine. This is a high speed 2L engine build.
Used pump components must be carefully examined for any potential re-use. Some things that happen to oil pumps in use, over time, are really amazing. Main shafts can twist like cork screws, gears wear tapered, lower housings get re-machined by gears, idler pins get oval, relief valve pistons erode, and relief valve springs weaken and shorten. The lists go on and on. The actual pump design, from the early 750's to date, is a good solid design, and despite the odd things that happen with use, these pumps can be rebuilt, essentially blueprinted, to perform better than when they were new, for specific applications.
 

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humm, more thinking out loud, with something spinning that fast in a liquid it's placing a high demand on the suction side of the pump and any impediment on that side could cause cavitation thus a drop in pressure just as high loading could cause the prezel?
 

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Not sure about that, but various sources offer different types of pick-up screens. I have found that if they are occluded, the total pick up screen area is more than adequate. I paint them with Glyptal, some teflon coat them.
Now, if you have low oil in the sump, or if you somehow manage to slosh most of it up the side of the block in racing, and the pump sucks air at high speed, and then the pick-up is immersed in oil again, this can cause shaft breakage. The gear type pumps don't really get into cavitation like a water pump, they do suck air.
 

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The problem is the cam lobe on a flat tappet or follower. Push rods and rocker arms don't count. My Briggs & Stratton log splitter engine is an "L" head design, with flat tappets. Roller lifters ("roller-cams") are exempt. Old Ferrari single cam v12's with roller rockers are almost exempt, except for the tiny adjuster that contacts the valve stem tip. It acts like a flat tappet, and you will end up with metal transfer pits on the adjuster tip, or worse, the valve stem tip even with ZDDP!
There are some excellent articles here on the BB about the necessity for ZDDP additives in oil for Alfa engines. The material acts like a high pressure lubricant as the cam lobes move over the follower and the molecular oil is essentially swept away, (simplified) leaving the follower with no oil cushion. This will give you Alfa followers that look like this, and ruined cams as well.
but haven't you seen this before they started removing ZDDP? can we blame every cam and tappet failure on the loss of ZDDP? I haven't experienced this problem
 

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Yes! Absolutely! Usually caused by a combination of dirty oil, and followers that are not correctly hardened. With Ferrari's the little adjusters showed metal transfer, UNTIL reproductions appeared from Japan! The trick was to make the just a bit softer than the valve stem tip. They still wear with flat spots, which is corrected by slight adjustment.
Alfa followers, once headed south, take the lobe with them, imbedding debris which will then eat new, good followers.
My point is that if you are not using the latest generation of catalytic converter, and you are not required to follow government mandates with oil, the ZDDP will not do any harm, and in many cases has shown to be an excellent high temperature, high pressure friction modifier in engine lubricants.
Further, it is my understanding (not necessarily fact!) that factory installed break in oils do contain ZDDP, and plenty! The stuff may (my word) form some sort of molecular bond and remains imbedded in the valve gear, providing lasting protection for the required (my word) 100,000 miles.
This is much like the old leaded fuels. Once the lead is in an engine, it stays there for a long time.
My feeling is that with racing, and vintage engine restoration, ZDDP is not a bad additive. This is, just my opinion from my experience.
 

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Redline is a good reliable company. There ZDDP can be used with conventional and synthetic, I believe. Check with them to be sure. The cost isn't that much, so I would just use it as they suggest. Your 3 way catalytic converter may not last as long as your engine then, but so what?!
 

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Back on pump thinking, what about the non gear type that seem to be used every where now. Like is used on the V6.
why not just use that type of pump. it would seem better then making custom gears?
Some cars have the same type on the crank. So it would be runing 2x the speed of cam speed pumps. So they must be good for hi RPM use.

Any thoughts?
 
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