Ex. valve breakage

Here's a tip for teams running the squire cut ex. valves and two piece lash caps, STOP using them after a wile the lash cap cuts into the valve and it breaks right at the tip and gets sucked into the motor, we broke two at the Gainesville points meet, and messed up two heads and two pistons and one sleeve, there are new valves and keepers that have round keeper groves so they don't cut into the valve. A tip from the frendly TERENZIO RACING TEAM.

 

radius grooves

I agree. The only way to fly now is with radius groove or "bead-lock" valves and keepers. The old used since the beginning of time square groove locks tear up the groove on the valve,ESPECIALLY when you have detonation issues. Almost every time you look at the valves after detonation the square grooves are all tore up, but with the radius grooves, all is like new and happy still. We ran round grooves all season, and at the end of the year the locks and the grooves still looked new. We tried the one piece 10' lash locks, and it is scary how the bottom of the lock bites into the valve and creates a stress riser. I have seen many broken valves and the resulting carnage is not pretty. We had the best results with seperate lash caps and 7degree radius groove locks. One disadvantage with the Brad VI heads is they only have a .250" tip on both valves and you can't use the deep lashcaps. Conrad at Victory says he has some true 7degree one piece lashlocks that work but I have not tried them yet. With the rpms and abuse these motors take this area is a constant ongoing problem. Any other ideas out there? Dan

 

I bought some Arias heads a few weeks ago that has one chamber all beat up because it dropped a exhaust valve, and guess what kind of locks it had. It broke the stem right at the bottom of the keeper groove. When I first saw these one piece lash locks I thought it would be the cats meow, but after what I've seen and heard I dont think I'll use them. Is it usually the ex. valve? What about the intakes? I know the exhaust valves usually dont have a problem with seperate lash caps wearing on the tips of the valve, so no problem using them there, but the shorter intake rocker moves across the tip alot more wearing the valve tip. Thats where the earlier Brad fat heads were nice with the .400 deep lash caps, they couldn't rock around on top of the tip.I've heard the Brad 6's have had alot of trouble because they went back to .250 tip. These 1 piece lash locks would solve the problem, but I'm scared to use them now.
I think the problem is, because the valve keeper groove doesn't have any pressure on it untill the valve is closed, and there is not a constant pressure on the keeper groove, any movement acts like a sledge hammer when the valve closes.
Does any one make a 1 piece lock with the radiased groove?

 

lash locks

the exhaust seems to be the most problem with the lashlock. I think is is because by design, the geometry is really bad. The intake rocker has a roller which maintains he geometry better and rolls across the top, where the exhaust rocker is being dragged across the valve and as it opens and closes, the ratio and contact area is changing alot which causes sideloading and rocking of the lashlock, which digs into the side of the valve.
Victory Performance does make some 7 degree radius groove one piece lashlocks, both in jumbo7( actually 8degree od), and a true7 degree outside. You've gotta be very careful with locks and retainers to make sure they are designed for each other. My suggestion is call Conrad @ Victory Performance, he can explain it better than me.704-799-1950