"Motor Broke" (Hendricks)

[jacksoni]

Anybody seen some of the posts about the Hendricks motor/engine failures last weekend. New gear ratio was supposed to be easier on the engines. Funny valve train failures. Sounds just like what Don said in one of his CDs about valvetrain harmonics destroying engines. They lowered the rpm, thinking might be better, but got into bad area valvetain wise. Thoughts?

[OldSStroker]

Anybody seen some of the posts about the Hendricks motor/engine failures last weekend. New gear ratio was supposed to be easier on the engines. Funny valve train failures. Sounds just like what Don said in one of his CDs about valvetrain harmonics destroying engines. They lowered the rpm, thinking might be better, but got into bad area valvetain wise. Thoughts?

IMO, Hendrick Motorsports MUST have (at least one) Spintron, and tested their valvetrains at the rpm range run at the track.

What you said has happened in the past when the valvetrain harmonics were designed for a certain rpm range, and because of parts breakage, etc. the team owner/engine builder decided to drop the max rpm a few hundred rpm....right into a bad harmonic which the engine accelerated through with the initial gearing, but where it dwelled at the end of the straight with less gear. At that time, only the cam company that speced the valvetrain had a Spintron or earlier equivalent, even though the Cup team with the problem was a TOP team.

My guess is that the top ($) Cup teams cycle engines thru race rpm ranges not only on a Spintron but on a programable engine (or chassis) dyno for at least the target number of cycles or engine revs, which is in the 1.0-1.5 million range, I suspect. Shoot, if they are using 7 post chassis rigs, they must have Spintrons.

Does anyone here KNOW what max rpm NASCAR is shooting for? My best info was about 96-9700, even though I thought it would be under 95. Perhaps it was to keep them out of 5 digits which was coming.

My $.02

[k-star]

When i was down at the Hendricks complex this past fall i could hear a dyno running and it was cycling the engine like it was at a track. I would guess by the sound it was a super speedway engine..

Keith

[OldSStroker]

When i was down at the Hendricks complex this past fall i could hear a dyno running and it was cycling the engine like it was at a track. I would guess by the sound it was a super speedway engine..

Keith

Daytona/Talladega plate engines run in a couple hundred rpm band at speed...nearly at one rpm the whole way around. The shorter super tracks might have a 13-1500 rpm band which starts well above the max plate engine max rpm.