i "heard" roller cams don't get adequate lubrication during long periods of low rpm idling: http://www.foleyengines.com/resourc...am-problems-gm-43-v6-vortec-industrial-engine Is this true? If so, is there anything that can be done to get around this, besides switching to flat lifters?
Every current production engine has a roller cam. Rollers need less lubrication than a flat tappet cam. IF it's a race car with huge valve seat pressure, flat or roller, they need the cam splashed by oil slinging off the crank to be happy.
That is the first I heard of a roller cam needing more oil and putting a flat tappet cam in to solve the problem.
Total crock......i have run solid rollers on the street, in traffic, for over 25 years with no issues.....especially with the new pressurized lifters of today
If you read the link the OP posted it pertains to a specific engine and specific applications...It IS NOT an across the board issue!
I don't know why it would be that way with industrial 4.3L engines. Are you planning on using a modern industrial engine??
It might be true, in the specific applications: "This includes applications such as constant speed 1800 RPM generators, oil well pumping units, or in an application such as a forklift or wood chipper where the engine idles for long periods of time at very low RPMs" Doesn't seem to be an issue in normal automotive use.
I am a dealer and have sold lots of cams and lifters--here is the deal with solid rollers A Street application is WAY different from a race application--In a race application spring pressures around 225-235 seat and 550 minimum to as high as 900- open are common--those run for very short periods with almost no prolonged idle time--when at idle and with those pressures the needle bearings in the lifter wheel are subject to little oil and a rough life and can fail--Pressure fed oil to this critical area ups the life and the Price of solid roller lifters--bushed axles are a common answer but with even higher price--real race engines with higher pressures should invest in the best lifter you can afford Street solid rollers torture these axles worse than higher pressured race units because of Prolonged periods of idle with little to no splash oiling--so...everyone would benefit from the highest quality lifters you can find-- Morel makes very high quality USA made lifters in a variety of price ranges and features to handle any application--Isky also does the same--Johnsons rollers are USA made maybe but are trash in my opinion--I build engines for a living many of Comps lifters are borderline unless you spend the big bucks then I would much rather have the Iskys or top featured Morels So....buy pressure fed oiling if you can--if you can't keep street pressures reasonable by buying STREET ROLLER profiles which do not require the higher spring pressures--often these lobes can run great with as little as 150 seat and 425 open which is much easier on the lifters Talk with your engine builder for best info--he sees all of the products available and should know what can do what for your build.
interesting you asked I sold many of the first retro style available--you see stock style that run in all current new engines have pretty low spring pressures so they are great--the retro style that fit older engines are mostly Morels ( the BEST) or Johnsons and a smattering of import junk Here is the deal-- John Callies ( of Callies crankshaft fame) is the designer/owner/ ramrod at Morel lifters --that is all he does now he said to me in person--the street style retros should have spring pressures that don't exceed 145 seat and about 340 open---do NOT do the old trick of 3/4 turn or more preload--use 1/4 turn for preload!!! What this means is you have to be very careful ordering a hyd roller for street use--the lobe design of the cam ( and RPM desires) dictate the spring pressures to control that certain lobe design--many makers have caught on and are making great hyd roller cams that are designed to operate correctly with the lower pressures mentioned--Many do NOT and sell wild computer designed lobes that Require higher pressures than most lifters are capable of--Now the exception is higher priced hyd roller lifters that are designed for more spring pressure --Morel makes two steps--one that will work with higher RPM higher pressure street deals and one that is for race only--both are much higher priced than regulars and both have oil weight requirements and Still have spring pressure limits--you run almost zero preload with these--my take on hyd rollers for retro applications is this STAY AWAY from Johnsons--seek out Morel made ( under a lot of brand names) be sure you are talking with someone that Knows--Bullet Cams is one of the best, Isky is also, Comp...ehhh... you may get a good guy on the phone and maybe not--they use lifters from many different makers to keep the line up stocked--you may also buy good lifters from places like Howards--they also know the cam business--they sell almost every lifter made even some very good entry level solid rollers by a company named Steen--these are usually the black coated ones you see reasonable $$ they ain't bad if you keep pressures under control--also Howards usually has great tech guys Using a factory roller block you can use stock replacement style for $120 a set IF you keep grinds on milder side and pressures on the Low side just a little above stock range-- Excessive pressure on the wrong lifter with WRONG preload is the culprit on many troublesome hyd roller cam swaps--also bear in mind that some of the hyd roller retros like for example a 440 Mopar are VERY HEAVY per pair and thus limit RPM by that fact alone careful matching and parts selection is Critical for a good happy results--talk with experts not the cheapest guy you can find
i guess i should have been more specific: i was concerned about: 1) In stock or mild performance automotive applications. However, idling at red lights, stop signs and even warming up in the driveway would likely not constitute "long periods of idling at low RPM," and thus are no cause for concern. However, i'm still curious in these situations, do roller cams in fact receive less lubrication than a flat tappet cam and if so why? And my concern was not just for the 4.3 chevy; i figured that the 4.3 is similar, if not identical to regular v-8 small blocks in the cam department. So the question was really for all engines in general. 2) In actual industrial applications where the engine really DOES idle for hours/days at a time at low rpm---500 to 1000 rpm. 3) OR in automotive cases where there IS quite a bit of idling----i.e., taxicab, cops who sit under bridges etc. I'm not really concerned about super hi-performance or racing applications, although the info is interesting to know.
I doubt GM would design an engine that was under oiled. I have read that when you put roller cams in an engine that didn't have them originally you have to do things to make sure that oil gets to the proper location. Something about the fact that there is too much oil loss early on in the oil passages when you run rollers in that engine.
stock style engines like you speak of can idle for a darn month--they get plenty of oil--they have very low spring pressure--- which in high perf applications starts the road to potential issues if correctly matched parts are not used--I love rollers which make break in issues thing of the past--they are wonderful but when you step away from stock --that--is where you must be careful and tales of woe start to appear if it is not a matched up combo of parts-- Stock--NO problems retro deals and hot grinds with mismatched parts--you betcha
Roller cams are used specifically because they are low friction. That also means they require minimal lubrication. A few drops of oil on the roller bearings and they are happy. Lubrication is MUCH less critical than on a flat tappet cam both in quantity and quality. As for why GM 4.3s have problems, if they do, Chevs have a long tradition of using shitty cams and lifters. In the seventies and eighties one of the most common problems on a Chev V8 was a worn out (flat tappet) camshaft. The local auto parts stores had replacement cam kits stacked on the shelves like cord wood.
Thx DD73, I'm running solid flat tappet now and very careful to use a synthetic oil that specfies high ZDDP for hi po flat tappet engines, But I see and hear so many stories of flattened lobes and cupped lifters that I guess I'm a bit "gunshy"! I bought Comp Cams lifters with the .012" oiling hole in the lifter face for the SBC in my Hiboy.
If your lifter bores are OK not too big, not scratched up etc, you have oil with high ZDDP , correct spring pressures and get your flat tappet off to a good start then...it will run a good long life as long as you keep on using good oil--now we have dozens of good choices You will be fine--maybe see ya at Greer Nov 5th we plan on bringing the dragster and having fun--still smarting from not going to Myrtle Beach but guess I would have held up the tra la la turning a 200 inch dragster around for return trip back up the track LOL
C-10 I find it interesting that the article written by Foley claims their flat tappet is the answer to a questionable issue they speak of. Since when is 1800 rpm considered a low rmp. Don't today's vehicles with OD cruz within that rpm range ? Dusterdavel73, I enjoyed reading everything you've shared with us.
Yeah, I expect that would have been a real task, to turn that rail around on the track! Gonna be at RWYB in Reynolds, GA next weekend, and there's a real possibility I'll be @ Greer the next Sat. 11/5.
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