Composite Flat Tappets

Rick Parker · #1 (**permalink**) 04-11-2004, 10:09 AM

I have no firsthand experience with these but the idea look promising. Good example of thinking outside the box. They claim some benifits regarding break in periods. We seem to dread this initial 30 minute period after fire up, perhaps this could help. Pricey? Yes, but what isn't on one of these cars?????

www.SchubeckRacing.com/flat

Rick

Cracker · #2 (**permalink**) 04-11-2004, 12:16 PM

SFiredog - the on-the-side engine builder who does excellent work uses these in engines with flat tappets. When visiting his shop late last year he pulled a set out and I couldn't believe how light those were! When building engines means lowering the weight of all critical moving parts these lifters has to be at least 3 times lighter than my traditional solids. Yes - pricey but what the heh!

SFfiredog · #3 (**permalink**) 04-13-2004, 10:52 AM

Tony,

The tunnel port with Schubeck lifters goes on the dyno tomorrow.

--Mike

Cracker · #4 (**permalink**) 04-13-2004, 11:44 AM

Mike,

I assume your FINALLY referring to YOUR engine! Call me and let me know how it goes - I can't wait!!!

Congrats!!!

Mr.Fixit · #5 (**permalink**) 04-13-2004, 12:01 PM

Super expensive, and no real big benefits.
One testimonial claimed a 5 hp increase. Well let me blow an extra $600 on lifters for 5 hp, I sure wouldn't want to spend that money getting my heads ported for a worthwhile increase. Why not go for a roller cam if you have the extra money? Unless the racing sanctioning body prohibits a roller cam, but do you race your cobra in a sanctioned racing series with engine teardowns? The only real advantage I see is if you change camshafts more often than underwear, than you don't have to keep your lifters in order. Weight savings: that extra $600 will go further in improving power if spent on ultra lightweight crank, rods and pistons, or a very low M.O.I. flywheel/clutch assembly. I guess if money is absolutely not an issue, and you allreqady bought the absolute best of everything else....

Sizzler · #6 (**permalink**) 04-13-2004, 07:22 PM

Quote:

Originally posted by Mr.Fixit

Super expensive, and no real big benefits.
One testimonial claimed a 5 hp increase. Well let me blow an extra $600 on lifters for 5 hp, I sure wouldn't want to spend that money getting my heads ported for a worthwhile increase.

Your opinion. I'd like to actually SEE that testimonial. Else, why would Ti valves and retainers be desired, only saving an ounce or so there?

My question would be: what is the expected longevity of these composite lifters? 10,000 miles? 50,000 miles? 100,000 miles? Any actual testing on that parameter?

Mr.Fixit · #7 (**permalink**) 04-14-2004, 08:27 AM

Titanium valves and retainers are there to reduce mass at the valve, so the valves can actually get closed at very high RPM without bouncing. Remember that mass at the valve is 1.7 times more critical than mass on the other side of the rocker arm.

Sizzler, you want to read that testimonial, and the others? Just go to their website. http://www.schubeckracing.com/flat

their main advantage seems to be in racing classes such as NHRA stock eliminator, where rules are very strict about what you can do to your motor, and racers change cams as often as tires.

go to the Q/A section, happy customers

Sizzler · #8 (**permalink**) 04-14-2004, 11:28 AM

They must still save a lot of weight.
I imagine they could be used on the same ramps/cam as a hydraulic roller lifter, but be able to stay with/on the cam, due to their lighter weight, to a far higher rpm. This is what I'd be interested in. Would still like to hear experience or opinions regarding the expected longevity of the Schubecks though.

Rick Parker · #9 (**permalink**) 04-14-2004, 11:39 AM

I would imagine that due to less mass, that lighter springs could be used effectively, reducing friction and increasing resultant (useable) horsepower. Dissimilar materials at the contact surface would also lessen the chance of wiping a lobe off the cam.

Rick

Mr.Fixit · #10 (**permalink**) 04-14-2004, 04:18 PM

The frictional losses at the lifter / cam interface are tiny, in the overall scheme of things.

"They must still save a lot of weight." (sizzler)

Where do you geys get the idea that their lifters are really light? Even they don't claim that. They have one type of "ultralight lifter" that is all composite, but only one testimonial. Most of the flat tappet info is about their steel jacketed composite tipped lifters, and they don't claim that product is much lighter.

"I imagine they could be used on the same ramps/cam as a hydraulic roller lifter, but be able to stay with/on the cam, due to their lighter weight, to a far higher rpm. This is what I'd be interested in." (sizzler)

What makes you think that? They make no such claim. If the lifter has a flat base, the cam's ramp angle can only get so aggressive before it stops riding the base of the lifter, and rides the corner. Roller cams get their rapid opening rates because they have a rounded lifter bottom. You can use mushroom or radius lifters to push that a bit, but they have their own drawbacks.

their big advantage is zero break in, that's really it. Since you guys don't turn your motors to 8000 rpm, weight isn't really an issue for your valvetrain yet anyway.

Cracker · #11 (**permalink**) 04-14-2004, 06:40 PM

SFiredog - How did it go?

Mr. Fixit - I think he (Sizzler) might of been speaking of my general comment about how light they were - not Schubeck(?). I have to tell you whether they say it or not it was substantial. With that said you know more about everything relating to engines than I so I appreciate your perspective on these and other topics. Does this mean we won't catch you with these?

BTW, I don't go to 8K rpm's but I touch 7,500 several times but I run TITANIUM!!!

Mr.Fixit · #12 (**permalink**) 04-15-2004, 08:32 AM

They have their place, but I don't race any vehicles in a class that requires a flat tappet cam, (and frequent cam changes) such as NHRA stock eliminator. Neat concept, I am curious if it takes off among other manufacturers or OEM's.

SFfiredog · #13 (**permalink**) 04-15-2004, 10:20 AM

The tunnel port is up and running and it sounds awesome!
I will be making the power pulls today.
Be patient, I will explain all about the Schubecks when I get more time.
--Mike

cobrashoch · #14 (**permalink**) 04-15-2004, 10:32 AM

A buddy of mine that runs a C/stock Dodge index car is trying them right now. So far he reports bent pushrods, but that may be due to another problem too. Then again it could be the lifters expansion co-efficient that tightens the lash on engine warmups. That's the book on lightweight solid lifter designs down through the years. Bent pushrods.
Cobrashock

Ant · #15 (**permalink**) 05-15-2005, 05:04 PM

I have read two different posts on ceramic lifter failure, and it would be hard to judge what caused the problems.

I am going through the motions with a leading engine builder sorting out 427 engine makeup and what scares me is if something fails prematurely I might not have the cash to fixit.

My builder recommends a Solid roller mild camshaft with .650 lift, from what I can gather roller cams have better torque etc, and as I am after over 600bhp with either a 450 cuin, or 468 cuin engine, I would prefer to stay flat tappet with the best quality lifters and change them all at say 20,000 > miles, but I guess there is more driveability and power with the solid roller. I read these horror stories of roller lifter failure, but one aspect with the needle rollers in the lifter is it never really stops and gets an impact - normally!!

SFfiredog · #16 (**permalink**) 05-16-2005, 10:35 AM

Ant,
Could you direct me to the posts you mentioned about ceramic lifter failures. I would like to hear what the failures are.
Thanks,
--Mike

Ant · #17 (**permalink**) 05-16-2005, 08:51 PM

Mike,

I am trying to find them, as far as I know they one shattered through maybe incorrect valve adjustment, and the other was a Camaro that had them but failed and the guy vowed he was staying with a flat tappet normal lifter!

I have spoken to my builder and the decision is either Jesel solid roller lifters or the Ceramic Schubeck, as I am not convinced that a properly setup roller with not to high spring pressures to go to 7200rpm max this setup should be reliable with the Shelby block oil system, also with Schubeck lifters the only point on those for me at the moment is the hp loss compared to the roller, but having said all that the car is a road racer and will see more road miles that the track by far!!

SFfiredog · #18 (**permalink**) 05-16-2005, 10:01 PM

First, let me start by saying my wife is from Australia and I had the pleasure of visiting friends in NZ while "down under". New Zealand is one of the nicest countries I've ever been to. Absolutely beautiful and every person I met treated us like friends and family. Lots and lots of car people and the vintage warbird scene is one of the best in the world.
I have built 6 engines with Schubeck flat tappet composite lifters and absolutley love them. I can get really aggressive on the lobe design, almost approaching roller cam lobes, using a flat lifter.
Maintenence is almost zero, the engines go thousands of miles without even needing a valve adjustment. I can run much higher spring pressures, 160 lbs to 190 lbs on the seat. Those pressures would kill a regular lifter, and the composite requires no break in.
If you want a roller lifter, Schubeck makes what he calls a "Roller X" lifter that has the trunion and roller made of the composite material that uses no bearings. These are not the same as the radius lfters tha Schubeck sells. The Shelby block is not really friendly to a "dog-bone" style lifter because there is no room to mount the stud that holds the lifter plate in place. (the lifter galley bracing gets in the way) This would hold true for the Jesel "dog-bone" lifter as well. You will have to run a "link" roller lifter. The Jesels are excellent but very pricey. I have had good luck with the Crower "hipo" pressure fed lifters.
I have built a few Shelby block engines and just took delivery on a new Robert Pond Aluminum FE block. It is really nice.
Let me know if I can be of any help.
--Mike

Ant · #19 (**permalink**) 05-17-2005, 12:07 AM

Mike,

Good to read your post, and the nice things about this little country, yep I come from the middle of the South Island, and have seen the Warbirds in action especially Sir Tim Wallace piloting the Griffin engined Spitfire.

By the way my wife is from Dorset in the UK, and she had to go home last year which put the Cobra project back a bit, and now I have started on this one which is about to come from the UK.

Thanks for the information on the Schubeck flat tappet lifters, this is the first post I have read with any real substance of someone using them and in a position to give good feedback with all the engines you build!

Regarding my car doing more road miles than anything else I am considering the Schubeck flat tappet and as you say a more agressive camshaft design, do you think the X rollers are any better, as I am after reliability first, but while I am it the performance of a roller camshaft appeals greatly, and I have been given figures from KC of 30hp over a flat tappet. I am thinking Jesel to do it properly. Decisions Decisions!!!!!!!!

By the way what make of conrods do you use?

SFfiredog · #20 (**permalink**) 05-17-2005, 03:19 PM

Ant,
I only have read and seen the Roller X lifters, I haven't run any in an engine yet. I always try to refrain from positive or negative comments on any product unless I have actually used it, but I have heard good things about them so far.
As far as con rods are concerned, it depends on the application.
On lower horsepower, or shorter stroke engines (engines without high piston speed) I use Scat or Eagle rods and have had no problems as long as the rods are sized properly for bearing clearance. For mid level engines I like the Oliver Forged rods. The Oliver forged rods are very good and very comparable in price.
For example, let's say you get a set of Eagle rods for $450.00.
Add in the ARP 2000 rod bolts for another $140.00 and re-size the big ends and you are almost into the price of the Oliver rods which are lighter. For higher horsepower or big stroke (high piston speeds) I like Oliver billet rods.
--Mike