Broken Valve Guide LS3 Trick Flow 255s
Thread Starter
Joined: Apr 2017
Posts: 305
Likes: 11
From: Washington NC
Broken Valve Guide LS3 Trick Flow 255s I put the car back on the dyno and immediately noticed a rattle sound coming from the top of the motor. I brought the car back in the shop and compression tested it, driver side rear cylinder was at around 160psi. I pulled the head of and the piston was chewed up. After removing the valves from the heads i notices a large chunk of the valve guide is broken off. What the hell?
They are brand new trick flow 255's only and few dyno pulls on them. What now? What could have caused this? Defective? Cracked when the heads were put together?
Input please.
They are brand new trick flow 255's only and few dyno pulls on them. What now? What could have caused this? Defective? Cracked when the heads were put together?
Input please.
That really sucks.
As to how it happened, that looks like a powdered metal guide, and it likely had a non metallic inclusion for it to fail like that. Without seeing it in person or looking under a microscope, that is.
Edit - are you missing some aluminum near the base of the valve guide also?
As to how it happened, that looks like a powdered metal guide, and it likely had a non metallic inclusion for it to fail like that. Without seeing it in person or looking under a microscope, that is.
Edit - are you missing some aluminum near the base of the valve guide also?
Thread Starter
Joined: Apr 2017
Posts: 305
Likes: 11
From: Washington NC
That really sucks.
As to how it happened, that looks like a powdered metal guide, and it likely had a non metallic inclusion for it to fail like that. Without seeing it in person or looking under a microscope, that is.
Edit - are you missing some aluminum near the base of the valve guide also?
As to how it happened, that looks like a powdered metal guide, and it likely had a non metallic inclusion for it to fail like that. Without seeing it in person or looking under a microscope, that is.
Edit - are you missing some aluminum near the base of the valve guide also?
Thread Starter
Joined: Apr 2017
Posts: 305
Likes: 11
From: Washington NC
What's the valve look like? Rocker? Your lucky you caught it right away.
The piston looks ok and you might get a free head. Might be a bad batch of guides or a one off with a fracture. I wonder if they x ray the guides before installation?
The piston looks ok and you might get a free head. Might be a bad batch of guides or a one off with a fracture. I wonder if they x ray the guides before installation?
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Thread Starter
Joined: Apr 2017
Posts: 305
Likes: 11
From: Washington NC
Valve and rocker are fine. My problem is that it's got me gunshy about the rest of the guides. Im nervous if i put it back together and it happens again it could be far worse.
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Originally Posted by topspeed1
Valve and rocker are fine. My problem is that it's got me gunshy about the rest of the guides. Im nervous if i put it back together and it happens again it could be far worse.
Thread Starter
Joined: Apr 2017
Posts: 305
Likes: 11
From: Washington NC
Steel Guides = Best Hi TS, I fit a steel guide when possible, our Induction Hardened German Steel Guide.
I can supply our Steel Guide ?
MY GUESS is another FOUND CASE of a cost reduction COSTING END USER BIG MONEY (-.50 cents savings each guide)
Lance
I can supply our Steel Guide ?
MY GUESS is another FOUND CASE of a cost reduction COSTING END USER BIG MONEY (-.50 cents savings each guide)
Lance
In general, I like powdered metal. It's is usually quite consistent from part to part, which is one of the big advantages. The only real downside, it won't be as "solid" as a, err.., solid cast piece. There is always some measure of porosity. And when things go wrong, they tend to go wrong in batches, so with one failing, i'd replace them all. But I would not expect the replacements to also have defects. Where powder is ill-suited is in applications where it's going to be very thin, threaded, knurled, etc. It's still not as tough as cast and machined steel.
Yeah, the difference is that bronze wears BEFORE the valve stems, but that itself can cause other issues. Especially with a very hard valve like titanium - hence the LS7 valve breaks you hear about from time to time. For stainless, which is actually quite soft, bronze guides are great. But GM did their homework on everything, and it's not like there are broken down GM's from bad powdered guides on the end of every driveway right? So, powdered is not bad. OP just got unlucky and got a defective one.
I have to say, I'm very tempted to run these with the titanium valves in mine. When I upgrade the heads, Ill be in touch.
I have to say, I'm very tempted to run these with the titanium valves in mine. When I upgrade the heads, Ill be in touch.
Thread Starter
Joined: Apr 2017
Posts: 305
Likes: 11
From: Washington NC
TECH Fanatic
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From: Wilmington, De
Yeah, the difference is that bronze wears BEFORE the valve stems, but that itself can cause other issues. Especially with a very hard valve like titanium - hence the LS7 valve breaks you hear about from time to time. For stainless, which is actually quite soft, bronze guides are great. But GM did their homework on everything, and it's not like there are broken down GM's from bad powdered guides on the end of every driveway right? So, powdered is not bad. OP just got unlucky and got a defective one.
Bronze also has certain inherent lubricating qualities. The downside is that it is soft, so any sort of sideloading is going to exacerbate guide wear. This is why a roller tip rocker is heavily suggested for any head with bronze guides.
Thread Starter
Joined: Apr 2017
Posts: 305
Likes: 11
From: Washington NC
I still dont have an answer from Trick Flow. I have sent them several emails today and a voicemail. with no response. I understand that racing is racing and stuff happens, but i feel like this i a cut a dry manufacturer defect.
Here is a copy of their warranty
Trick Flow Specialties guarantees original, unmodified cylinder head castings against manufacturing defects. Trick Flow Specialties’ liability is limited to replacing the casting.
The valves, valve guides, valve seats, valve job, valve springs, valve spring retainers, valve locks, rocker arm studs, guide plates, and valve stem seals included on assembled Trick Flow Specialties cylinder heads are warranted to the original purchaser to be free from defects in materials and workmanship for a period of two years from the date of purchase.
This warranty does not cover:
• Failure due to improper installation or maintenance, abuse, misuse, unauthorized repairs, modifications, or alterations determined at the sole discretion of Trick Flow Specialties. If your machine shop, engine builder, or installer performs any unauthorized repairs, the warranty is voided and Trick Flow Specialties will not reimburse any cost you incurred.
• Removal or replacement costs.
• Costs incurred due to down time of the vehicle.
• Damage to related components.
• Marine salt water corrosion.
• Corrosion from not using and/or refreshing antifreeze.
• Fitness for purpose or merchantability.
All other Trick Flow Specialties products are warranted to be free from defects in materials and workmanship for a period of 90 days. There are no mileage limitations.
I bought them on January 15, 2018 which was 60 days ago
Here is a copy of their warranty
Trick Flow Specialties guarantees original, unmodified cylinder head castings against manufacturing defects. Trick Flow Specialties’ liability is limited to replacing the casting.
The valves, valve guides, valve seats, valve job, valve springs, valve spring retainers, valve locks, rocker arm studs, guide plates, and valve stem seals included on assembled Trick Flow Specialties cylinder heads are warranted to the original purchaser to be free from defects in materials and workmanship for a period of two years from the date of purchase.
This warranty does not cover:
• Failure due to improper installation or maintenance, abuse, misuse, unauthorized repairs, modifications, or alterations determined at the sole discretion of Trick Flow Specialties. If your machine shop, engine builder, or installer performs any unauthorized repairs, the warranty is voided and Trick Flow Specialties will not reimburse any cost you incurred.
• Removal or replacement costs.
• Costs incurred due to down time of the vehicle.
• Damage to related components.
• Marine salt water corrosion.
• Corrosion from not using and/or refreshing antifreeze.
• Fitness for purpose or merchantability.
All other Trick Flow Specialties products are warranted to be free from defects in materials and workmanship for a period of 90 days. There are no mileage limitations.
I bought them on January 15, 2018 which was 60 days ago
Thread Starter
Joined: Apr 2017
Posts: 305
Likes: 11
From: Washington NC
Well i guess trick flow obviously isnt gonna help me out, so im gonna have to pay out of pocket to have them repaired. Also Im gonna install bronze valve guides and say the hell with the powdered metal ones. Going to get a new valve job too.