the brand new Crower hydraulic flat tappet cam went flat and destroyed two engines

From what I've seen, the issue is the lifters which also take out the cam. There is one and only one manufacturer left that makes high quality flat tappet lifters (Hylift Johnson) and they have a couple of grades of lifters depending upon the use. They can be purchased through some specialty cam grinders including Jones Cam Designs. Perhaps twice the cost of what Comp or Crower will charge but they won't destroy your engine. Be aware that you may not be able to grind a hydraulic roller lobe onto a solid roller core (or vice versa) and have it last. It has to do with the thickness of the heat treated surface and the difference in lobe shapes between solid and hydraulic cams. Also, most cores have a rough shape (to minimize grinding time and cost) that limits them to a range of duration, lobe separation angle and lift. There are full round cores but they are quite expensive to grind to a finished shape due to the time they have to spend on the grinder. Also, existing roller cams can be reground to a different set of specs within a certain range. I have several possible solid and hydraulic cams that could be reground depending upon your anticipated specs. BTW, my machinist, Dave McLain, has one of Crane Cams refurbished Van Norman cam grinders and has reground several cams for me. FYI, I'm working on a proposal 7 days per week which is due 17 July so may be slow to reply until then. Dan On Wed, Jul 2, 2025 at 4:16 AM Mike Drew via DeTomaso < detomaso@server.detomasolist.com> wrote:

From Dan Courtney….

Sent from my iPhone Begin forwarded message:

From: Dan <dan@excaliburre.com> Date: July 2, 2025 at 09:51:08 GMT+2 To: Mike Drew <MikeLDrew@aol.com> Subject: FW: Roller Cam Core Needed



Hello Mike, I checked all the issues I’ve received but it still looks like my posts are not posting.

I’m sending to the correct email address, right?

Could you please post again?

Sincerely,

Dan

From: Dan <dan@excaliburre.com> Sent: Thursday, June 26, 2025 11:00 PM To: 'detomaso@server.detomasolist.com' <detomaso@server.detomasolist.com> Subject: Roller Cam Core Needed

I’m seeing more activity on the forum these days so thought I would re-post this request.

I’m down to just needing a cam to get The Winged Warrior running again after over a decade.

I lost my “enthusiasm” after replacing 3 351c’s in three months.

The last two got just 200 to 250 miles before the brand new Crower hydraulic flat tappet cam went flat and destroyed two engines, including a crate Boss.

Crower replaced one on a warranty, but that went flat right away also.

Now I’ve requested a replacement hydraulic roller cam but they are requiring me to furnish a core.

So, does anyone have a 351c roller cam core? Could be a hydraulic or a solid lifter cam, as long as it’s a roller.

Dan Courtney

La Jolla, CA

[1]Dan@excaliburre.com

(

References

1. mailto:Dan@excaliburre.com _______________________________________________

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the brand new Crower hydraulic flat tappet cam went flat and destroyed two engines From what I've seen, the issue is the lifters which also take out the cam. There is one and only one manufacturer left that makes high quality flat tappet lifters (Hylift Johnson) and they have a couple of grades of lifters depending upon the use. They can be purchased through some specialty cam grinders including Jones Cam Designs. Perhaps twice the cost of what Comp or Crower will charge but they won't destroy your engine. Be aware that you may not be able to grind a hydraulic roller lobe onto a solid roller core (or vice versa) and have it last. It has to do with the thickness of the heat treated surface and the difference in lobe shapes between solid and hydraulic cams. Also, most cores have a rough shape (to minimize grinding time and cost) that limits them to a range of duration, lobe separation angle and lift. There are full round cores but they are quite expensive to grind to a finished shape due to the time they have to spend on the grinder. Also, existing roller cams can be reground to a different set of specs within a certain range. I have several possible solid and hydraulic cams that could be reground depending upon your anticipated specs. BTW, my machinist, Dave McLain, has one of Crane Cams refurbished Van Norman cam grinders and has reground several cams for me. FYI, I'm working on a proposal 7 days per week which is due 17 July so may be slow to reply until then. Dan

On Wed, Jul 2, 2025 at 4:16 AM Mike Drew via DeTomaso <[1]detomaso@server.detomasolist.com> wrote: From Dan Courtney…. Sent from my iPhone Begin forwarded message: From: Dan <[2]dan@excaliburre.com> Date: July 2, 2025 at 09:51:08 GMT+2 To: Mike Drew <[3]MikeLDrew@aol.com> Subject: FW: Roller Cam Core Needed  Hello Mike, I checked all the issues I’ve received but it still looks like my posts are not posting. I’m sending to the correct email address, right? Could you please post again? Sincerely, Dan From: Dan <[4]dan@excaliburre.com> Sent: Thursday, June 26, 2025 11:00 PM To: '[5]detomaso@server.detomasolist.com' <[6]detomaso@server.detomasolist.com> Subject: Roller Cam Core Needed I’m seeing more activity on the forum these days so thought I would re-post this request. I’m down to just needing a cam to get The Winged Warrior running again after over a decade. I lost my “enthusiasm” after replacing 3 351c’s in three months. The last two got just 200 to 250 miles before the brand new Crower hydraulic flat tappet cam went flat and destroyed two engines, including a crate Boss. Crower replaced one on a warranty, but that went flat right away also. Now I’ve requested a replacement hydraulic roller cam but they are requiring me to furnish a core. So, does anyone have a 351c roller cam core? Could be a hydraulic or a solid lifter cam, as long as it’s a roller. Dan Courtney La Jolla, CA [1][7]Dan@excaliburre.com ( References 1. mailto:[8]Dan@excaliburre.com _______________________________________________ Detomaso Email List is not managed by POCA Posted emails must not exceed 1.5 Megabytes DeTomaso mailing list -- [9]detomaso@server.detomasolist.com To unsubscribe send an email to [10]detomaso-leave@server.detomasolist.com To manage your subscription (change email address, unsubscribe, etc.) use the links above. Members who post to this list grant license to the list to forward any message posted here to all past, current, or future members of the list. They also grant the list owner permission to maintain an archive or approve the archiving of list messages. References 1. mailto:detomaso@server.detomasolist.com 2. mailto:dan@excaliburre.com 3. mailto:MikeLDrew@aol.com 4. mailto:dan@excaliburre.com 5. mailto:detomaso@server.detomasolist.com 6. mailto:detomaso@server.detomasolist.com 7. mailto:Dan@excaliburre.com 8. mailto:Dan@excaliburre.com 9. mailto:detomaso@server.detomasolist.com 10. mailto:detomaso-leave@server.detomasolist.com