Is it true that some are having issues with the YT at higher RPMS? Say 6500 to 7100? I will be purchasing a set mainly for insurance reasons.

 

What issues have been seen?
I ordered mine for peace of mind. I just spent $16K on a stroker so $400 didn't seem like much. I did run into a problem though. I'm currently only spinning to 6k RPM's and managed to break one of the YT's on cylinder 8. By today's standards I don't know if my cam is considered mild, moderate or what but, YT is replcing the entire set. Nasty Perofrmance has the broken one now, I'll see if we can get a picture posted.

 

silent1 you are the only person I have ever heard of breaking one.

My motor is seeing 7000 on the dyno and it's been fine.

 

YT said I was the first to manage to break one and they were very surprised. I don't know if it's plain bad luck or what. I also managed to be the first to break FLP's input shaft according to them.

 

The issue that 94Form2000Z is talking about happended not too long ago when a few cars rwhp would suddenly just drop in the higher rpms. While the actual cause was not established it's more than likely not enough spring pressure and the valves were starting to float.

 

I run YT's for a piece of mind and spin the motor to 6800rpm regularly..

 

That is the issue I heard about. I guess the extra weight didn't help the lifters any.

 

Well on my old setup We did 2 Dyno pulls and without taking the car off the dyno installed the YTs and did another 2 pulls that gain 4rwhp on 1 pull 7 on another... go figure. As to stock rockers, I had 3 shed needles in my engine so the YT was the answer for me... BTW they went into my 427 also

 

We did 3 different cars and changed the rockers out on the dyno. Ozz as mentioned earlier picked up 6-7rwhp after the install, another H/C car picked up 7rwhp and we did it on the RMS car..actually did it both ways. Put them on and gained 4rwhp, took them off and lost 4rwhp. I wuold say they are worth 5rwhp most of the time.

 

I think I'll go ahead and save up to make this my next mod. I'd hate to have one fall apart and loose the needle bearings. After all I'm twisting mine up to 6800. Hopefully my lifters hold it.

 

What part broke?

 

What about if your stock lifters have a abnormal amount of preload? I had a cam (26/224 110lsa), 7.4" Chromoly push rods and 918 springs. When my buddy got to putting the stockers back on, he said there was an unusual amount of preload and he had to shim them he said. The car runs fine, but when i took it to the dyno, it isnt making the power that he expected it too. He talked to the guy that make shis cams and they both agreed that Imight be getting valve float. Do you think that yella terra's would benefit me in my instance? Maybe releave the excess preload? I really wouldnt want to spend $500.00 for something that I can better use the cash some where else.

Mike

 

If the preload is too much with 7.4's, maybe 7.35's would be a better fix.

 

But would there be too much preload using 7.4" with a cam like that?

Here is my lift:

Peak lift with 1.7's:
Intake .585
Exhaust .568

 

For interested parties: I might have a set of YT's for sale very soon. There brand new in the box. I think I'm going to an adjustable set-up. Interested parties can contact me via e-mail at Beast96Z@team.camaroz28.com
I'll sell um cheaper than the stores, but not to much!

 

bumper' up

 

I also had a stock rocker go out and found needle bearings in my oil pan nothing else was wrong with the engine.

 

Probabley not with stock uncut heads. Taking a little preload out with shims won't hurt power though. Actually, it may improve the power some. What was the actual preload before using the shims and how much did he shim them?

Also, I've seen your dyno. You are not getting valve float. You would see a sudden drop off in power on your dyno graph of they were.

 

The back half where the push rod meets the rocker. It happened on my way to work one morning. There was no traffic so I was hittin' the throttle pretty hard and then I got a vibration in the truck. Any time I let off the throttle it would backfire. When I got to work, I pulled the valve cover off and found the push rod sticking out from the rocker and the broken piece sitting in the corner of the head. I would of thought the push rod would bend before the rocker would break but the push rod is fine.

 

Reboot,

Talk to Shaun (93pony) he is the one who did it. He said he shimmed them .030" and then took like 1 3/4th - 2 turns on stock rockers. Does that sound right?