Paranoia about breaking in a flat tappet cam - and one possible neat solution.

Kind of like a "Spintron" for flat motors???????

Seems you would need the spring pressures, and maybe some heat, other than what you may generate by friction..............heat lamp maybe?

 

I Know of one guy who does basically that, for break in and wear testing.
His is driven by another gas powered motor, on a test stand.

A treadmill motor might not be powerfull enough.

 

Not a Great Idea, but
I saw on TV the other night some auto manufacture runs a "cold test" on new motors before the final asmbly. They spin the motor, measure intake va***e at eact cly. exh volume at each cly, oil pressure, listen for noises, yadda, yadda,

 

You might use lighter than usual valvesprings; similar to what some engine builders are using with light springs and low-ratio rockers (obviously NA on a flatmotor) for break-in.

I think there was some discussion of this topic (cam break-in) in the PHR "Engine Masters" magazine recently. The motors they build for that compe***ion use fairly radical flat tappet cams.

 

For just a little more work, you could build a proper dry spin stand, and break the whole engine in at once. Remove the spark plugs and it would only take a couple/few HP to spin it. Maybe an old motorcycle or riding mower engine? Fab up a pully to bolt to the crank hub that connects to the power source via chain or grooved belt.

You could even buy a replacement water heater element at home depot, and run it on 110V, and it could get the coolant up to 200*+ rather easily.

You could mount a oil pressure guage to it, and with minimal heat and the plugs out, monitoring compression and statistics could be done on the fly.

Maybe even some more creative options here... With the dizzy installed and energized, you could set the timing, or even power tune the distributor... Mount a cheapo tach to it to sit beside the oil pressure guage to monitor RPM's.

Exactly how many engine builds do you do a year? If you did more than 4 or 5, such a contraption might be a prudent investment.

BTW, about the biggest electric motor you can get for 110V is ~1.5 HP. Anything bigger will require 220V up to about 9 HP, then you get into commercial electrical service [3 phase]

 

Sounds like a neat solution to keep from ***embling your final engine combination , firing it up and chancing a wiped cam with the resulting teardown. It would simulate the cam grinders recommendation of starting a fresh engine (with a fresh cam) and running it at 2,000/2,500 for a half hour to break it in. After running it in you could than dis***emble it from the test engine, examine it for any potential wear on the cam and lifters and have an ***urance that it would survive in a "real world" invironment.

Frank

 

this takes way more HP than you think,i have done this.

 

Ok...... And......................
You gonna share some of your expirence?

There's a wrecked Hona Rebel 250 in my local cl***ifieds for $150. I dunno, what... 12-15 HP? Think that might get 'r done?

 

Doesn't havign the cam/lifters in a different block defeat the purpose of "breaking" them in. I am under the impression that it's those slight manufacturing tolerances that we all know vary from engine to engine - are the reason we break in - at least some of the parts - otherwise wouldn't the manufacturer's do it??

I'm not saying this is a bad idea - just not sure it's gonna do exactly what you want it to do. I wonder what the cam manufacturers would think of such an approach.

 

Here's my take on this mess. You had better break the cam in with the block that you intend to run the cam and lifters in !! Never saw 2 blocks with the same lifter index in all my days of thrashing engines. For all you cats that don't know what lifter index is, it's the placement of the lifter bore in the block as front to back and left to right. Plus the cam depth will vary from front to rear in every block and the core shift will vary in the block from the block centers >>>>.

 

I'm with the naysayers above, and do think the original question involved a dedicated "break in block".

Even though the engines are the "same" there will be slight differences in lifter placement and angle. Only takes a thou or two to negate any break in.

******** you may say so here's data points. For decades I've given away high performance chevy cams, ones that got installed in high mile motors and used for 20K. Upon removal a 4x4 is drilled and marked as a lifter block so the lifters stay with the lobes.

My buddies install em in other high mile stuff, and those cams never ever ever make 2 years. Repeating break in only seems to hasten the process.

Good luck whatever you do

 

Not real sure,but isnt oil splash the main lifter lube source? In that case the rods are needed,and why RPM is 2000 +-. No expert,but a long held idea.

 

It's a nice idea, in theory, and others have tried it before.

My opinion, FWIW, is that *** POSSIBLY *** this might work, if you had your spare block and your good block both reworked with BHJ's Lifter-Tru & cam tunnel fixtures...at least they would be somewhat closer to identical...but still not there. And they never will be identical.

I still wouldn't do it, though. In spite of all the hype & fear about oil, ZDDP, cam failures, etc., etc., etc., it is still not terribly hard to break in a flat tappet cam. It takes a bit more effort & some thought, but it can be done.

BTW, the Spintrons use 25, 50, 75, 100, 150, 200, or 250hp motors depending on the model.

As a final note, Scott Main of MPG Head Service/Cam Research offers a break-in service with new Ford cams, using a machine. I've seen a number of people say on the Net that they planned to use it, but I've not seen any real world results.

I agree with Shifty regarding used cams and their longevity...the only used cams I buy are damaged rollers, because they can be reground to something else.

 

i know that some of the Nascar teams use a device based on an engine block to break in new cams , or at least they did at one time. about 10 years ago , next door to the shop i was working at was a custom camshaft manufacturer. they made cams for several Nascar teams and the owner showed me a video of a camshaft being broke in at a Nascar team's engine shop on such a machine.

i was sworn to secrecy as to who it was.... but as a hint , they called him the "King"


here is a link to the cam makers website , it was a fun place to go over and snoop around:

http://www.integralcams.com/

 

I'll throw some more chips on the table here. Let's say that you built an engine back in the day and took it to the track. Damn thing ran like hell and kicked *** to boot.So let's say this went on for quite awhile and you just knew that it would be something you would have to TRY and duplicate. So back to the drawing board and off we go to replicate that same engine. Months later you go back to the track with engine #2 and get suprised as the 2nd engine doesn't perform near as good as the 1st. Now your really scratching your head because you used all the same stuff and even degreed the cam the same way as the 1st engine. Now here's the deal. We discovered that the lifter placement and the cam location in the block would have an effect on the cam timing and how the engine would perform. Now the cam was only 1 item in the mix but the lifters would make 16. Now in the perfect world they came up with the fixtures to somewhat correct these problems and to relocate the lifters in the block. This doesn't answer your question about breakin a cam in but it is a point on the subject >>>>.

 

With the nascar stuff is you know they've bushed & blueprinted the lifter bores and cam position to 10X the precision of any stock block. Probably a key difference.


Edit...enginepro sure is a fast typer with good info!

 

----#### Man I **** at typing !! I use the HUNT and Peck Method !! LOL >>>>.

 

Engine Pro , good points. i'm sure that the factory had some loose tolerances and if you made your own break-in machine from factory parts and blocks that you will get some inconsistency

i ***ume that a Nascar race team would start with a bare un-machined block and do all the machining in house on CNC equipment ...including lifter bores and the cam location...so that their break in device would be an exact copy of the actual engine they run in the race cars. i know they spend gobs of money on their engines, and have smart people working on them..so i'm sure it's something they have considered.

the average guy (like me) would have never even gave it a thought... until now. it would seam the end results depends on the quality of the tools and equipment you use and your skill.

 

Another point as someone has suggested duplicating a good running motor. The Nascar boys know what every combination they build (and there are several dedicated to specific tracks) will pull for horsepower. If a completed engine is as much as 3-4 hp off the standard it will be torn down to find why it was off. With todays quality control it's possible to duplicate anything automotive related to a finite degree. Don't believe it? Take a tour of a top NASCAR shop and see for yourself. After being involved in the development of the current S2B2 GM Nascar engine and taking a tour through Hendrick Mototsports engine facility I was amazed at the detail taken to produce a winning engine.

Frank

 

yeah , i know that those Nascar engine builders are very **** about them...the cam maker told me that the teams would request very small changes in the cam spec's. who would think that .002 lift or a half degree duration would make so much difference?

if i recall correctly , the initial break in was with lighter valve springs...then switched to the heavier springs that would be used in actual compe***ion . of course , they are only used for one race then pitched in the s****.

 

All of the above...indexing, need for oil splash from full ***embly, need for lots of power for full ***embly (read Yunick on trying to spin full engines in earliest days of flow testing!) add in mucho trouble. Flatheads with streetable cams rarely have any cam troubles...and I know you had a LOT of trouble due to crummy repro lifters. Get good lifters, use ***embly lube, maybe put in extra oil for run-in like Honest Charley said in 1960. Don't worry. And don't runnitin on a stand or anything...fresh engines shouldn't be run like that except for a few moments to see that all is well. It should break in under fairly normal stress and with varied speed and load in the car on the street.
NASCAR is the uttermost extreme of cam problems...very highly stressed engines forbidden by rules to run the roller cams they need.
Hard core old days mechanics ***embled their Zephyr valve springs onto the ***emblies BY HAND. Try that on a full race Chevy and you'll see how lightly stressed flathead lifters really are!
On of Red's "engine talk" columns discusses the multiple current sources for lifters and how to avoid the absolute **** ones.

 

I have seen this done before with a small block chevy. The guy cut out the cam/lifter area of the block spun the cam with a electric motor used a spray bar to flood the cam/lifter area with oil and if I remember right some type of adj spring system to slowly increase the pressure on the lifters. He charged to break in cams and seemed to be doing a good business.

 

Another big problem with cam break-in is the spring pressure. Too much and you grind the **** out of things. Too little and you don't apply enough pressure to the lifters for the correct rotation pattern and you grind the **** up. This is why the invention of break-in rocker arms has taken place. Same rocker with a lower ratio as to not put too much stress on the lifters and the lobes. Just won't work on a flat-head .. Confused yet ??? >>>>.

 

You wouldnt have to spin the whole engine would you?

As long as you get enough oil to the cam mating surfaces?


So I guess you could make a couple of parts to bolt on an engine that is getting a new cam...

A couple of chunks to clamp in the main bearing caps to keep the oil in.
A oilpan that has some jets to spray oil on the cam.
A timing cover with a drive attachment to hook a 1,2 or 5 horse electrical motor on to.
( and probably an other couple things to keep the oil inside...)

Should be doable if you want to go through the trouble.

 

Hi Crew,

Quick question - what's the deal with running an old cam with reground lifters? I decided to regrind the lifters that came with my flathead as I couldnt be confident that the lifters were placed in exactly the same hole as they were broken in with.

Danny

 

Danny,

This thread may be of some help to you, but you have to pick & choose. http://www.jalopyjournal.com/forum/showthread.php?t=235262

 

New cam , new lifters end of story . with what the rest cost ,why scrimp on the cheapest part in the build .besides,who likes tearing down flatheads .