I ran .685 btr springs on the last motor and shifted at 8k on every pass Anyways, I've got my eye on another complete set of heads that are set up with 1209x springs.

 

Sucks but the parts failures, I'm sure off the web you kicked a few things around the shop.

 

Is that the valves with the friction welded head. Did it break/bend near the heat effected area of the friction weld if they are. That bend would indicate the valve bent before breaking no?

 

I'll admit to losing my cool and cracking a 8" bench vise in half using a 3 pound hammer and that's all I'm gonna say....lol

 

The valves didn't contact the pistons if that's what you're asking. Erik special ordered these pistons to work with my head and cam set up. We also verified clearance when the motor was assembled.

 

I can understand that, but on this head, it's a whole different scenario for that same spring. Different cam, different lobe design, bigger(heavier) valve. Lot of things. Again, I am not downplaying the spring itself, but just seems like not the forst pick for your combo. This could just be simply bad luck and a unique failure-odds added up. My gut still feels it floated the valves, though. Too many things sorta point to it in my mind. Wish you luck, so sorry you didnt get to enjoy it more. If you have not already bought new heads, look at the Greg Good CID LS7 heads or the MBE Brodix LS7 heads. Either are monsters you would be very happy with.

 

springs came from guy who picked the valves to match his cam.

 

Troy,

This statement is NOT factual as proven by your own words and our conversation & our texts after your 421" grenaded. You said a piston "kissed" a valve after you upped your shift point from 7000-7200 RPM.

Then you told me "Assembler" closed shop and left town before you could speak with him after the failure. You also told me you did not know or have record of PTV clearance and had also used 5/16" x .080 wall PR.

While it appears highly likely in this current situation a Ferrea valve failed in your 468" this did not occur in your 421".

Blaming Mamo Motorsports for a Ferrea valve failure is like blaming GM or Ford for a Takata airbag failure. In both cases one manufacturer trusted the reputation of another quality manufacturer's parts and Ferrea valves have an excellent reputation.

Unfortunately racing breaks parts obviously and you have broken a lot of parts to reach your goal of a 9-second truck and an iconic photo/avatar including engines, transmissions, and suspension/chassis components as well.

You have paid for many expensive lessons and to imply that the same valve failure occurred both times is disingenuous.

@BigDaddy97
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@BigDaddy97

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Default 447 stroker on the way!Well 2 weeks ago I had a catastrophic failure with my 421 (4.030 bore x 4.125 stroke) at the track. Over the winter I had a local shop swap the heads out for some Tony Mamo AFR Mongoose LS3 heads and a FTI powerglide. I've been shifting at 7000 and running upper 10.20's with no problems but decided to try 7200 and see if it would pickup, when a valve kissed a piston. The heads are destroyed, 1 piston is trashed, 1 bent rod, block is cracked, the cam is good. I spent so much over the winter that I'm now on a somewhat limited budget to get racing again. The shop that did the work won't respond to me at all.....grrrrr. So I decided to get the best/biggest shortblock I can afford,thus I ordered a 447 (4.155 bore x 4.125 stroke in a sleeved Gen iv block) from Texas Speed but then I will have to make due with what I have on hand for the rest of it, I have a set of CNC 821 heads from Katech Engineering, stock rockers with Straub bushings, 11/32 pushrods that are .120 wall, LS7 lifters, and I will reuse my hydraulic roller cam which is .623/.623 lift, 247/261 duration, 113 + 4 lobe sep, and also have a new LOD Speedworks intake that was ordered prior to the engine failure. Obviously I would like to get a nicer set of heads, and a LLSR setup but it's simply not in the budget at this time (maybe next year). My question to you guys is: I think I can break well into the 9's with this big engine that has a mild top end, what do you think? I would also like to thank Dan Miller (aka NAVYBLUE210) for his messages and phone calls of support and advice.....you're a great guy and it's much appreciated!
__________________
1997 S10, HPR 468 stroker, 13.5 to 1 compression, MMS 265 LS7 heads ,Carbon PST intake,105mm throttlebody, Custom Clydesdale ******* HR cam spec by owner,80 pound injectors,1 7/8 headers,FTI powerglide,FTI 8" 6000 stall,8.8 rear,4.10 gears.


Last edited by BigDaddy97; 07-06-2019 at 02:54 PM.

 

Dan, actually it was never determined if the valve hit the piston or if the Rev valve broke on it's own. True the shop closed and would not respond to me, and that's when he suggested to me that since they wouldn't respond, they probably didn't check valve clearance and it probably hit the piston which is when I made that post, but I can also tell you that right after this happened he quit using Rev valves and switched to Ferrea. This raises an eyebrow for me, and I also remember you saying that this made you nervous because your MMS heads had Rev valves .When I ordered the last set of MMS heads I was assured that the Ferrea valves would be fine but to not go above .700 lift. I spec'd my cam at .675 lift and used 3/8 .135 wall pushrods. Tony himself stated to me that he felt this Ferrea valve looks as if it broke at idle and not during a run. I was then told to take my complaints to Ferrea and that I should look at the glass as half full since the entire engine wasn't destroyed. This didn't set well with me, because in my eyes he is Ferrea's customer not me. I was his customer. I did not update this thread to talk about him or throw him under the bus and actually stated that I didn't want to post any drama. I'm not happy with MMS and will take my business elsewhere from now on, simple as that. I posted to give an update as to what happened and will post further updates when the motor is re-done.

 

Could there have been an underlying cause for the failure?

 

I'm curious too.

 

I can tell you that a big name reputable engine builder that is a member here told me that these Ferrea valves have failed multiple times while on his engine dyno.

 

I think it’s a bit harsh/premature to be blaming Tony for a valve breaking.
i bounce mine off the limiter, 7600rpm , every time I drive it, over 30,000m
If you don’t want things to break , throw a stock engine in, but even then ,that’s not 100%certain.
When I looked at your pics, I thought the valve may have contacted the outer edge of the valve relief, I suppose that’s the head suppliers fault also
i think the saying goes “ you pay to play”
Sux you had this failure, hope all goes well when it’s back up n running

 

And I think it's a bit premature of you to say whose fault it is or is not, especially when you don't know all the facts. I didn't post everything I know because I don't want the drama.

 

Big daddy now that you have all this experience what valves are gonna use next time? I am sorry this happened to you. But I,we are learning what not to use.

I have been running 650 lift stuff with the Ferrar valves but on cathedral stuff for several years buzzing them up to 7500 for hundreds of passes.I am swapping over to ls7 stuff so paying close attention to others failures and successes.

 

Del West or Manley titanium valves which have the hardened stem so no lash caps required. It sucks Big D and I didn't like reading about issues with Ferrea hollow stem valves, especially after having installed some in my L92 heads. I'm not going to worry too much about it though as these aren't the LS7 valves and I'm not running a solid cam and lifters with 3/8 pushrods, shaft mounted rockers that require additional spring pressure. We can only assume that the one valve just didn't make the grade but yet passed inspection and then failed while the others held up.

 

Victory Titanium has been reccomended to me by several people, so I'm gonna look into them.

 

I have run the Xyledene (10+ years) and the Manley titanium with the hardened / steel ends and have worked out pretty good. The key is to get the steel tip to avoid lash caps as somehow the lash caps over in the Corvette Forum seemed to get lost / forgotten about and in a 50 miles the roller tip has worn through the bare titanium and Shazam.

 

So what the assesment, defective part or valvetrain was not set up right?

 

My builder's and my assessment is a defective valve. Talking to a major engine builder who is a member here, says they've seen several of the Ferrea valves come apart which supports this. Tony himself said the valve appears to have broken during idle.