Anybody running solid lifters?
Thread Starter
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Project C4 is right.
The lack of ZDDP (zinc) in modern oils leads to premature lobe failure with flat tappet cams. (proven fact)
The govt restricted zinc because it reduces the life of cats. (clogging)
Modern engines with roller lifters don't need the zinc anymore.
So a little online research reveals the "high mileage" oil blends have raised the zinc levels.
Or dump in a half pint of STP to recover the zinc without further worrys.
The lack of ZDDP (zinc) in modern oils leads to premature lobe failure with flat tappet cams. (proven fact)
The govt restricted zinc because it reduces the life of cats. (clogging)
Modern engines with roller lifters don't need the zinc anymore.
So a little online research reveals the "high mileage" oil blends have raised the zinc levels.
Or dump in a half pint of STP to recover the zinc without further worrys.
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Switching to roller lifters is not for race engines, all mfgrs have switch production cars to rollers.
Sadly the ZDDP problem for flat tappet cams is mentioned in small print with the cam mfgrs.
Just use the High Mileage Mobil 1 blend. It has the ZDDP you need.
Sadly the ZDDP problem for flat tappet cams is mentioned in small print with the cam mfgrs.
Just use the High Mileage Mobil 1 blend. It has the ZDDP you need.
Burning Brakes
Joined: Sep 2005
Posts: 993
Likes: 3
From: Iowa
Yeah if the oil is correct a solid flat tappet is ok to use. The downside is the lobe profile can't be optimized like a roller variant but it's all in what someone wants to do. I have run them both and with the proper oil never had a problem.
Also, the OEM's really like the roller tappets for camshaft design and parasitic draw in the emission choked, hp sells marketing of today. Durability could be had in materials and design on a non roller but the roller's benefits are enough to justify the costs. Just my .02
Also, the OEM's really like the roller tappets for camshaft design and parasitic draw in the emission choked, hp sells marketing of today. Durability could be had in materials and design on a non roller but the roller's benefits are enough to justify the costs. Just my .02
Thread Starter
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
I have no argument against a roller cam, it is by far a superior choice to a flat tappet. I did check on getting a roller and right at this point in time is not possible due to cost. The summer events are winding down and I have one more event I want to attend and it is less than a week away. While the cam I picked out is almost the same specs as the one that was in the engine before, there is a bit more lift on this one and it may well be that it could mean coil bind. I won't know that until I get some more parts that are due in tomorrow. If I had went ahead with a roller there is no way I could be done for this upcoming event even if I could afford one. I would have had to change the springs for sure then. Now before someone comes up with, "You mean you are not going to put new springs on?" and stir things up again, no, I am not because there is less than a thousand miles on the Comp Cam springs that are on the engine now. I know you guys mean well and I know you did not know the circumstances around this flat cam fiasco so while I respect and agree with your opinions, (most of them) I am doing things the way I want to do them at this time. That is my stand on this but keep the discussion going, it is good for others who are on the fence about what they want to do.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
I have no argument against a roller cam, it is by far a superior choice to a flat tappet. I did check on getting a roller and right at this point in time is not possible due to cost. The summer events are winding down and I have one more event I want to attend and it is less than a week away. While the cam I picked out is almost the same specs as the one that was in the engine before, there is a bit more lift on this one and it may well be that it could mean coil bind. I won't know that until I get some more parts that are due in tomorrow. If I had went ahead with a roller there is no way I could be done for this upcoming event even if I could afford one. I would have had to change the springs for sure then. Now before someone comes up with, "You mean you are not going to put new springs on?" and stir things up again, no, I am not because there is less than a thousand miles on the Comp Cam springs that are on the engine now. I know you guys mean well and I know you did not know the circumstances around this flat cam fiasco so while I respect and agree with your opinions, (most of them) I am doing things the way I want to do them at this time. That is my stand on this but keep the discussion going, it is good for others who are on the fence about what they want to do.
Thread Starter
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Thanks, I pulled the pan off & cleaned it out completely, there was some shrapnel. even so, I usually change oil after a cam change at 500 miles. I have a question and you will be able to answer it. How much lift will the 128 heads support without clearance problems at the top of the guide? I have Comp springs on the heads but I am still concerned about coil bind and the clearances
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Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
MIdnight Id guess it would be well under .500 in but couldnt say for sure.
Best thing to do is check one and see. Its a simple deal to take them down albeit an inconvenience
Wondering if you were getting some interference before and possibly the cause of your top end/cam problems?
Best thing to do is check one and see. Its a simple deal to take them down albeit an inconvenience
Wondering if you were getting some interference before and possibly the cause of your top end/cam problems?
Thread Starter
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
MIdnight Id guess it would be well under .500 in but couldnt say for sure.
Best thing to do is check one and see. Its a simple deal to take them down albeit an inconvenience
Wondering if you were getting some interference before and possibly the cause of your top end/cam problems?
Best thing to do is check one and see. Its a simple deal to take them down albeit an inconvenience
Wondering if you were getting some interference before and possibly the cause of your top end/cam problems?
I sure hope that is the case. If I do have a problem the car will be stored for the winter and it won't have GM 128's on it when it comes back out in the spring.