Flat tappet vs roller cam
Thread Starter
Drifting
Joined: Oct 2005
Posts: 1,331
Likes: 479
From: Appleton Wisconsin
Flat tappet vs roller cam
With all the talk about cam lobe failure should I buy a roller or flat tappet? The engine is a 454 10.5 com. pistons,torkerII, with a comp xe274s solid flat tappet cam. I have the engine apart, so now would be the time to make a change. I checked the lobes they are worn down .001 to .002, the engine has 1500 miles on it and I used valvoline 20w50 racing oil from the start. Is this wear normal for the miles? Thanks Gary
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
First off how are you measuring the lobe wear. You should be using a dial indicator with the cam being rotated on the bearing surfaces. You need to make sure there is no movement when you are spinning the cam. I just pulled a 294S solid flat tappet out of my 5K mile motor. It had less than .001 wear to almost no wear at all.
Would I go roller? If I had a spare 1K dollars around. I went to a larger solid flat tappet on my new 383 motor. The roller will give you a few more HP than the flat tappet but a solid roller will need attention and replacement of the rollers way more often than a solid flat tappet. Also you need less valve spring with a flat tappet. There are pros and cons of each you need to weigh them both and make your decision.
I have broken in many flat tappet cams and never had a lobe go bad. I remove the inner spring on my solid flat tappets for break in then go to the dual spring setup. Little easier on the cam breaking it in.
Would I go roller? If I had a spare 1K dollars around. I went to a larger solid flat tappet on my new 383 motor. The roller will give you a few more HP than the flat tappet but a solid roller will need attention and replacement of the rollers way more often than a solid flat tappet. Also you need less valve spring with a flat tappet. There are pros and cons of each you need to weigh them both and make your decision.
I have broken in many flat tappet cams and never had a lobe go bad. I remove the inner spring on my solid flat tappets for break in then go to the dual spring setup. Little easier on the cam breaking it in.
Thread Starter
Drifting
Joined: Oct 2005
Posts: 1,331
Likes: 479
From: Appleton Wisconsin
I used a dial indicator to measure the lobes, like you said. The cam specs are as follows:
Intake: .3340
Exhaust: .3400
Here is how the cylinders measured out
Intake 1 -332 Exhaust 1-340
2-330 2-340
3-332 3-340
4-330 4-339
5-332 5-339
6-330 6-338
7-332 7-339
8-330 8-339
Isn't it strange that the right cylinders all are lower on the intake?
Do you think this cam was possibly made this way?
Intake: .3340
Exhaust: .3400
Here is how the cylinders measured out
Intake 1 -332 Exhaust 1-340
2-330 2-340
3-332 3-340
4-330 4-339
5-332 5-339
6-330 6-338
7-332 7-339
8-330 8-339
Isn't it strange that the right cylinders all are lower on the intake?
Do you think this cam was possibly made this way?
Melting Slicks
Joined: Sep 2004
Posts: 2,412
Likes: 3
I read an article once that claimed a 30hp improvement. Don't know if that's legit. I have a roller cam and I like it. But one thing to think about, you might need stiffer valve springs if you want to spin your engine to high rpm. The roller lifters are much heavier than the flat tappet ones.
http://www.chevyhiperformance.com/te...8_0307_roller/
http://www.chevyhiperformance.com/te...8_0307_roller/
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
There is a much cheaper way to go roller than the retrofit parts. Look up a thread (that I started) from a few weeks ago that led to a discussion of using stock GM parts that are less likely to fail, anyway.
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
I would say that your cam has some wear on it. Like I said mine was less than .001 on all lobes.
It is real tough to compare a flat tappet to a roller. They are two completly diffent cams. Even if they advertise the same duration they will be quite different. The rollers get the valve off the seat much faster and stay at a higher lift longer due to the roller design.
It is real tough to compare a flat tappet to a roller. They are two completly diffent cams. Even if they advertise the same duration they will be quite different. The rollers get the valve off the seat much faster and stay at a higher lift longer due to the roller design.
Le Mans Master
Joined: Jan 2000
Posts: 8,721
Likes: 108
From: Canada
Originally Posted by I'm Batman
There is a much cheaper way to go roller than the retrofit parts. Look up a thread (that I started) from a few weeks ago that led to a discussion of using stock GM parts that are less likely to fail, anyway.
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Le Mans Master
Joined: Oct 2001
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From: Pine Bluff Arkansas
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21
I've had them all and if you got a lot of green....then go roller. Don't tell your wife how much your spending, or your be buying a new bedroom suite, too.(ha) I have a Crane roller and I love it, but I think I dished out about 800 not counting labor. But, I never have to wonder how it would be with a roller, tho. Larry
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
INHO if you want to go to a roller cam, then a solid roller is the only way to go.
This because a hydraulic roller will give you minimal if any gains at all over the same duratation solid lifter flat tappet cam and you will pay 3-4 times as much for it.
As a matter of fact if you put 1.6 roller rockers on the mechanical flat tappet cam if would out perform a similar duration hydralic roller cam
Now if you don't want to put a mechanical cam in for what ever reason then a hydraulic roller is a step up from a hydraulic flat tappet cam
This because a hydraulic roller will give you minimal if any gains at all over the same duratation solid lifter flat tappet cam and you will pay 3-4 times as much for it.
As a matter of fact if you put 1.6 roller rockers on the mechanical flat tappet cam if would out perform a similar duration hydralic roller cam
Now if you don't want to put a mechanical cam in for what ever reason then a hydraulic roller is a step up from a hydraulic flat tappet cam
Le Mans Master
Joined: Oct 2002
Posts: 7,098
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From: Las Vegas - Just stop perpetuating myths please.
Must have been a different article.
Originally Posted by torqvette
I read an article once that claimed a 30hp improvement. Don't know if that's legit.... http://www.chevyhiperformance.com/te...8_0307_roller/
No flames torqvette, but u need to be careful making claims without using references to back it up. Hearsay kind'a feeds on itself as we all have the craving for more pwr. :o
But even with 30hp a $900 cam upgrade is close to $30 per pony - not cheap. And if u really only get 10hp it becomes an expensive dissapointment.
cardo0
