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What did you do to your car today?
(11-04-2018, 09:47 AM)Carolina_Mountain_Mustangs Wrote: What I have stated is not an opinion but stressed by all cam manufacturers. Racing cam profiles and lifters will never last like a stock set up. Many want you to do very specific break in periods and may even ask you to break in with less spring pressure than when you are actually racing.
Due to the heavy spring pressure and the quicker and higher lifts the pressure on the cam and lifter is many times more than with a stock cam. When I worked in race engine shop the boss never let a built engine idle less than 900 to help save the cam. Even at that when we would tear them down that had been driven on street never saw one that was not junk after just a few miles. How many circle track cars do you hear loping at low rpm or professional drag cars? They are torn down quite often and everything changed. If you have a flat tappet cam the lifters do not rotate at lower rpm therefore causing more wear. Also the lubrication at a low idle is just not there. That is why only one or two lobes might wear more than others not the same amount of lube.
Racing parts are made to be ran not sit and idle. Talk to the cam manufacturer and see what they suggest for an idle speed and do some research. I think you will find that high lift cams with heavy valve springs will not hold up in the long run.
Here is some reading on cams there are dozens of sites and none will say to let a cammed up engine idle low. https://www.camcraftcams.com/some-though...fter-wear/

When you put a new engine together get a long travel dial indicator and take actual readings of the valve travel perpendicular to the valve. Check over time to see how the cam and lifters are holding up.
That is one of the benefits of the new engines today like the Coyote with their tiny little valves of less than 1" in diameter and very small springs. They do have 4 valves to make up for size.
Yes if you only drive to a few shows you will probably never have an issue but built engines just do not have a long life.

Guess with 11,000 on mine now I should plan a rebuild immediately then.................
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(11-05-2018, 11:37 AM)Tnfastbk Wrote:
(11-04-2018, 09:47 AM)Carolina_Mountain_Mustangs Wrote: What I have stated is not an opinion but stressed by all cam manufacturers. Racing cam profiles and lifters will never last like a stock set up. Many want you to do very specific break in periods and may even ask you to break in with less spring pressure than when you are actually racing.
Due to the heavy spring pressure and the quicker and higher lifts the pressure on the cam and lifter is many times more than with a stock cam. When I worked in race engine shop the boss never let a built engine idle less than 900 to help save the cam. Even at that when we would tear them down that had been driven on street never saw one that was not junk after just a few miles. How many circle track cars do you hear loping at low rpm or professional drag cars? They are torn down quite often and everything changed. If you have a flat tappet cam the lifters do not rotate at lower rpm therefore causing more wear. Also the lubrication at a low idle is just not there. That is why only one or two lobes might wear more than others not the same amount of lube.
Racing parts are made to be ran not sit and idle. Talk to the cam manufacturer and see what they suggest for an idle speed and do some research. I think you will find that high lift cams with heavy valve springs will not hold up in the long run.
Here is some reading on cams there are dozens of sites and none will say to let a cammed up engine idle low. https://www.camcraftcams.com/some-though...fter-wear/

When you put a new engine together get a long travel dial indicator and take actual readings of the valve travel perpendicular to the valve. Check over time to see how the cam and lifters are holding up.
That is one of the benefits of the new engines today like the Coyote with their tiny little valves of less than 1" in diameter and very small springs. They do have 4 valves to make up for size.
Yes if you only drive to a few shows you will probably never have an issue but built engines just do not have a long life.

Guess with 11,000 on mine now I should plan a rebuild immediately then.................

I myself have never seen an engine with what I would consider a radical cam and heavy valve springs, double or triple, and flat tappets go more than 2,000 miles on race track without a refresh. That being new cam, lifters, springs, push rods, bearings and rings. Everything else is inspected and crank polished most times. All the used stuff was sold to the guys just trying to get into racing.
I am by no means an expert but did work in a race shop for couple years so saw lots of engines go through. The boss was the man with the knowledge I was there to learn.
Drag racing is passes not that many miles. Some of the Chevy guys at Greer 1/8 mile in SS that wind the crazy rpm in 12 to 13,000 can only go a couple weeks without rebuild. 
Roller cams definitely have an advantage of less friction and generates a better profile without all the wear forces. That is why Ford used rollers the 302 starting in the 80's. I have a friend that drove his Ford PU 165,000 miles without an oil change. He would change filter occasionally and just add. I would never do that but he did and it worked. How well it works to be determined, lol.
I have taken engines apart with hydraulic lifters that the cam and lifters was eaten up but engine ran smooth just no power.


When a man is in the woods and talks and no women are there is he still wrong??
Tongue
David
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(11-05-2018, 06:00 AM)NOT A T5 Wrote:
(11-05-2018, 01:05 AM)libram Wrote: alright so idle arm replaced, steering is back again, speedo gear replaced for a 21 tooth and the flowmaster 50 series are out and dynomax turbo mufflers are in. Sound is much more bassy and the unbearable high pitches are gone and the db is way down for where it was.

libram, it would be nice if you could post another video of how your car sounds now, for comparison. 
Really like how the 50s sound.

I plan to, but its been rainy and crappy, need to take pics but I'd rather do it when its nice, I'll post a video too.
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Put my new quick fuel carb on and tuned it. Raining so I could not take it out and test so I am sure there will be some additional adjustments. Cam is pretty crazy so my idle is around 1050 rpm and is a full roller. Still sounds mean even at that.
[Image: 9-AA1-B8-CA-D688-41-B3-B16-F-B3-DE9-D6-A801-C.jpg]

Will post a video tomorrow.

'73 Grandé H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

'73 F code convertible. Bright red. Needs total restore. (IE HOT MESS)

- Jason
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moved to another thread.
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