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pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/17/13
03:23 PM

March 2013 CHP. "HOW IT WORKS" Comp Cams explains the new technoligy with their cams. It's very interesting reading as they are again telling us something that is new to some of us. Or is it? I am not going to give anyone my findings over the years. We are now the "Endangered Species" the "Old School Guys" as they refer to us NOW...LOL... They Think we don't know about metal coatings, and engine oil additives, that the EPA won out on by removing them from our engine oils.. Most of you GURU's have heard me say (I'M QUOTING MYSELF)... I wish I was born 20 years later. I want to see where technoligy will be in 20 years. I still believe that as technoligy is just fantastic....."ALSO VERY EXPENSIVE"...They want us to make Joe Gibbs richer that's all. $8-$9 a quart....for his oil.
  They tell us to use a ZDDP additive, but you can't use it in a newer engine, confusing. Yes! Back in the day when I had my Fords as daily drivers. I'd take the car in for a routine service, and guess what was used in the crank-case (Every Oil Change) with the 5 quarts of Autolite, Motorcraft and/or Rotunda engine oils. "Bardahl" an ANTI WEAR ADDITIVE! Then in the early 1960's Andy Granitelli came out with "STP" another engine Anti Wear Oil Additive to our engine oils. I put my very first engines together with "STP" as an assembly lube, and 50wsae oil..My assembly mix. It stayed, on the parts, it coated the parts until the engine was going to be run.
  Mechanical Camshafts back it the day were the factories hot set-ups. I saw few lifter, and cam wear problems, even in Big Block Chevys with high Valve Spring Loads. Usually it was a mal-adjustment, ot a failure. We drove our cars to and from the track and to and from work every day. Boy I loved the sound of those little mechanical marvels, and when adjusted properly it was a concert hall of music to my ears...LOL... The little ticking would be exhausted by a real dual exhaust system, the metal ticking carried to it's termination. You could stand at the exhaust and really hear the lifters tick. The metal exhaust carried the sound.
  I am a retired Mechanical Engineer and I worked in the Aircraft Industry early in my career we had some FBW, Metal coatings, Forgings, Strain Gauges, and all that good stuff. We did calculations by slide rule...LOL...
  The reason we heard of it because only the High End of the Automotive industry people could afford those luxuries. The NHRA, NASCAR, and F1 circuts. The guys that are out front, week after week are the guys that could afford those Luxuries even back then....Factory backed Cars. AA/FX etc.
  I also remember when there was a Chrome Plating put on an Exhaust Tip, as an Example only or pipe that didn't turn Blue in a "Very" short period of time. Most times it went through the salt of bad weather in colder climits.
  The article talks about ways we "Old School Guys" adjust hydraulic cams. So beit that's their opinion. How many of you younger gear heads, ever heard about adjusting an Hydraulic Cam to actually act like a Mechanical Cam.
  In closing the guys that want to have fun and carry on this great sport and hobby of our's will be competing against guys that are running $30,000 to $40,000 engines, and have already been seeing this for years.  We "Old School Guys" liked running what we brung. It was "Who Out-smarted the other GUY"... Grin  Cool
  IMO by the end of this decade, the words Flat Tappet Cams may not be in our Vocabulary. You younger Gear Heads are going to have FUN....Again these are only my observations. "JMOO".....Have Fun you guys. Grin  Cool


redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 01/19/13
05:07 AM

nice thread Bob.   times have changed, thats for sure.    the new technology is awesome, but seems to get expotentialy more expensive.    i can dig power adders, but tuning with a computer or programer is just not my thing.    and most of todays cars look hidiuos compared to the old muscle cars of the 60-70s.    JMO.  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 01/19/13
08:40 AM

Used to be a guy could tell one make/model from the next, even in the same manufacturer's family. Nowadays they all look the same and seem to only come in three colors, silver/grey, white, and red. I do sorta like the retro look of the new muscle cars, Charger/Mustang/Camaro, but everything else seems to be cut from the same mold.

My wife marvels at how I can be driving along, see a small section of a car or even a taillight hiding in someone's backyard/under a carcover, etc., and say that was a 195x, 196x, 197x, make/model, but can't identify the make of the car sitting next to us at a redlight.  
68scott385 68scott385 68scott385

WScott WScott
New User | Posts: 40 | Joined: 03/12
Posted: 01/19/13
03:38 PM

Bob i really enjoy reading articals on cams, amazing how much a
cam controls the way a engine runs throughout its entire rpm range
i am not a younster by no means and have been around build shops,
car shows, swap meets and race tracks and of course the place where
everyone knows everything the 5 oclock watering hole, BUT i have
never heard once how to make a hyd. cam act like a mechanical.
Sounds interesting, is there any performance gains in doing so,
could you explain the how to do this,

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 01/19/13
06:44 PM

A hydraulic cam set at zero lash, will perform similar to a solid.
Back off each valve until it clatters, then tighten until the clatter is "just" gone.,. that is zero lash.

When The Flag Drops.,.


The Bull ***t Stops.,.

P. Engineer, Engine Builder

pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/19/13
07:56 PM

Wayne: I hope I can answer your question. I'm going by memory, I'm glad to see guys are really reading our Forum and our Posts....

  I apolgize for taking so long to answer. Having trouble getting on board still.

Tuff has an answer to what we still do to get that extra 200 to 300 RPM.

Just a little back bround as to why some of us did this.
1. Cam technology was NO-WHERE near what it is today we all know that. With the Hydraulic Roller cams running at 7500RPM is proof as to the direction we are going these days. With all that said.

2. Guys that ran Strictly Stock or Super Stock classes could only run those cams. with those engines. We really needed more cam. Its funny how we gambled and took chances the way we did. Once things got of the bag guys were coming up with their own way of reinventing the wheel. We had a 283 with a Duntov 270 cam and it was far short of what we needed. We needed it back in the day we all cheated.
There was more street racing due to lack of tracks in some areas of the country....The old way of thinking we were all hoodlums, and were not far behind the bikers. Today with NHRA, IHRA, and NASCAR Tracks even Sturgis, the revenue such events brings in. Supports area towns for a year. "I just had to add that".

3.We needed to run tight clearances because hydraulic cams were ground mostly without take up ramps. (Unlike today).

4.Cams of that era if meant to run to 5800RPM may only go to 5400RPM. They lost it where it counted the most, the higher RPM.
  At first we thought it wasn't enough valve spring, so we shimmed them tighter, (Watching for coil bind, reatainer to valve seal, and valve guide hitting).
  We ran anti pump up lifters and zero lash always.

"Here is what I did and never had a problem".

Removed the spring clip from the top of the hydraulic lifter and replaced it with a Snap Ring. I collapsed the hydraulic lifter. (Making sure you are on the BASE CIRCLE of the cam).
  With the lifter collapsed (All Oil Bleed Out) your just relying on the little spring in the lifter. I then ran an adjustment of .003 to .008 between the rocker arm and valve stem tip. (Like adjusting take up ramp clearance on a solid cam). Then when you fired the engine it sounded like a Mechanical Solid cam.
  "Another point to remember" this cannot be done with Hydraulic Roller Cams. We passed tech. The vacuum was actually better. Now a cam that would run off and leave you at 5400RPM to 5600RPM would go to 6500RPM without a problem.
  Just a couple points: We replaced the wire snap ring with a real Internal Snap Ring.
  We ran more Valve Spring Pressure.
Make sure there is NO Interference in the valve train. The Push Rods are straight.

My brother had a Harley Davidson (Don't know much about bikes). It had an adjustable pushrod. I was able to do the same thing on the bike engine as I did on the car engine. It also had hydraulic lifters.

Thanks Tuff.....Some enginuity we had...LOL...


pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/19/13
08:02 PM


A few other things we did.

1.Removed the Spring and Plunger.
 Re-Assembling them with a piece of Drill Rod the sam diameter of course, leaving the intended clearance you wanted .003 to .008.

2.Ran Zero Lash and adjusted a clearance. .003 to .008

3.Same as #2 but some guys ran a 1.6 rocker arm ratio.

Remember we didn't cheap we improvised....


pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/20/13
02:13 AM

  It's 4am I remembered another way guys did this. They removed all the parts from   The hydraulic lifter. They stuffed flat washers in the lifter body to take up the space, then gave them the c;earance they needed then installed them on the cam.
  We took chances, and we won more then we lost. I know guys that did that to the 400 Pontiac engines, but don't know if the Chrysler guys ever did it.
  I do remember my friend with his '67 GTX where the push-rods stopped spinning and dented the valve covers.Chrsyler warranteed them too. Grin  Cool


pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/20/13
02:44 AM

  Did your wife say she was going to have you commited?...LOL... Thats a great remark and its true. If your a gear head your a gear head....I was told that a few times. Spend 4 hours in the garage and do nothing, but drink a case of beer, and bench race with your friends....I had 3 good friends back in the day. My wife was the only wife that would not go to the track. Thats a fact! She never said why, and I never pushed it either. Even when I drove the circle track and Busch cars. I was there by myself.
  I correct myself. She did come with me once. I went to Buck Baker's school. It was 1986. I went to get my Cup License/ from the Busch License. When I was on the track she was in the infield garage.
  Randy Baker talked her into jumping in a cup car and she went for a ride. This was at Rockingham. I explained how she was. I said if she takes 2 or 3 laps at 1/2 throttle, give her a ride. Man to my surprise she got out, and said Holy Chit we were 1 foot from the wall. But she never went racing with us. She's gone now and I guess that will always be an unanswered question?

  Another friend had a '65 Barracuda with the Formuls (S) Package. 273 with solid lifters. Geez that thing would run. It had this big 6"X4" exhaust and it was loud. Back in the day the cops would bust you for what they called. Unnessary noise with a motor vehicle. That was banging gears, melting the tires, and loud exhaust. Chrysler gave guys that had the Formula (S) Package a letter stating the exhaust was factory equipment.
  There was a trick for those engines (I believe it was the LA engines). You could change the rod angle by simply taking the pistons assemblies from the Right Bank, and swapping them to the Left Bank....Chrysler had a 7 year 70K mile warranty on those engines.
  So my buddie bought all the Chrysler gaskets in case it blew up and the Mopar guys looked at it, had the correct gaskets.


WScott WScott
New User | Posts: 40 | Joined: 03/12
Posted: 01/20/13
07:31 AM

Bob thanks for the instructions on how to make the hyd act like a mechanical,
you explained WHY racers did that back in the day. with all the different cam grinds available today would there be any advantage on trying
this on a Comps 280 hyd. also does that change any other charactoristics on a
cam like duration thanks

pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/22/13
01:05 AM

  Yeah but we have to attack it a little different. Thats all
My buddie and I have played with old technoligy cams and todays new technology cams. The base circle as we still refer to to it has more area. We can make more power with less camshaft to a point. There is a grey area, by that I mean we can move a cam 2* and loose power throughout the whole RPM range.
  When I pick a cam for someone I really try to get the most for them. I'm picking that cam as I were picking it for myself. When I start getting into my grey area around .600 lift and .268* dur. at .050. Thats what we have seen as a grey area.
  There is so much to consider when we are over that .600 lift. If I had a $1.00 for every time I changed a cam just for data. I have data I lost if someone took it Good for him, It's all in code....Dave the dyno guy and I think thats what happened. Its backed up. He had a friend of his dad that worked for a big cam maker. He was forced to retire, last year.