Don Terrill’s Speed-Talk

I'm shopping for LS beehive retainers and locks for 8mm valves and I've been seeing stuff labeled "300M mini top lock retainers, everyone in NASCAR is using them!" So 300M is an aircraft steel alloy?

PackardV8 wrote: ↑Tue Dec 11, 2018 6:48 pm I'm shopping for LS beehive retainers and locks for 8mm valves and I've been seeing stuff labeled "300M mini top lock retainers, everyone in NASCAR is using them!" So 300M is an aircraft steel alloy?

300M is modified 4340 with added alloys. It has more ductility and fatigue resistance than 4340. There’s more to that if you search on it.

Look up 300M and 300 maraging steel

There was a recent thread here on maraging steel retainers.

Hi Jack. Why would you need ultra duty 300m for lighter mass lower peak pressure beehive style springs? Even the dual conicals aren't that taxing compared to a big triple spring setup.


Maybe a high cycle endurance style motor? Why not cheaper slightly lighter Ti retainers and just cycle them out over time? Probably go through a few sets of Ti for the price of 1 set 300m's. lol

This is the thread
viewtopic.php?t=54888

I have to wonder if the retainers Jack is finding are really this material? Are they NASCAR take outs? Or have people seized this buzzword and just selling 4340 retainers?

Beehive retainers are small and light. With 8mm valves and beehive springs, I would think a quality 4340 retainer is enough.

If someone made them out of 300M there must be a reason why they did . Light weight steel retainers have been very popular in recent years. Better durability than titanium with a minor weight increase.

300M is what GM makes (or at least used to make) head bolts and main bolts out of.

I’m a bit confused while reading on speed talk about

Maraging Steel retainers in NASCAR !

Is the GM300M from the sixties and seventies

The same alloy??
Dave B,