Cylinder head repairable? (Triumph Street Triple 13)

S

self_moto

Well-known member
Hi,

So, I finally got to died engine to figure out what the damages are, and looks like it's only a cylinder head (including exhaust valves and piston of course). Rest of the engine looks good, haven't see any damages on crankcase, crankshaft, etc.

https://imgur.com/a/uKUPc4m

I'm wondering is it repairable? or should I just got a new head instead? Also wondering maybe you can suggest someone with experience in rebuilding of triumph engines? (I would like to get more power from engine after rebuild)
 
thePUNISHER

thePUNISHER

RAMPAAAAAAGE!
Ouch! I'm no master mechanic or anything but it doesn't seem like something that causes that much damage to the head wouldn't damage the walls of that cylinder just as much. Have you taken a close look at that? My gut says the cylinder walls of that cylinder are just as fuxored as that head is.
 
J

Junkie

gone for now
Anything's repairable if you throw enough money at it.

No hole in the piston?

looking at the parts fiche, intake valves are $51 each and exhaust valves $61. there's absolutely some welding and machine work required on top of that.

there are a couple heads on ebay for 300ish. you might be able to run a Daytona or R head for a few more ponies, I don't know. given the price of a (supposedly) good used head, I'd be tempted to go that way instead.

or, there are complete engines available for ~1k. I'd be tempted at that point, especially if Triumple specific forums say that you can easily swap a D675 engine for more power.
 
afm199

afm199

Well-known member
Is it repairable? Yep. Is it worth it. As Junkie said. No.

I've had that head problem more than once. I strip out the parts I want and throw the head on the recycle heap.

I buy heads on ebay. Be picky, look the pics, particularly the combustion chamber area. Look for low mileage heads. I won't buy anything over 5k miles and prefer under 1k. I've never paid more than $350 for a good GSXR hear.
 
S

self_moto

Well-known member
Junkie said:
Anything's repairable if you throw enough money at it.

No hole in the piston?

looking at the parts fiche, intake valves are $51 each and exhaust valves $61. there's absolutely some welding and machine work required on top of that.

there are a couple heads on ebay for 300ish. you might be able to run a Daytona or R head for a few more ponies, I don't know. given the price of a (supposedly) good used head, I'd be tempted to go that way instead.

or, there are complete engines available for ~1k. I'd be tempted at that point, especially if Triumple specific forums say that you can easily swap a D675 engine for more power.
Click to expand...

There is a hole in piston (added more pics), I guess that has prevented more damage... I went with whole engine replacement (last year), cost me 1200$ (for engine only).

Old/dead engine was laying in container for a year almost :) I'm thinking to rebuild it, swap with current one and sell current one (2 reasons why I'm thinking to rebuild 1) make so engine number match to title 2) get more power). Or just sell parts.
 
S

self_moto

Well-known member
thePUNISHER said:
Ouch! I'm no master mechanic or anything but it doesn't seem like something that causes that much damage to the head wouldn't damage the walls of that cylinder just as much. Have you taken a close look at that? My gut says the cylinder walls of that cylinder are just as fuxored as that head is.
Click to expand...

I was expecting same thing, but it looks "okay", no visible damage, and good thing that this engine has cylinder sleeves, so apparently those are replaceable.
 
J

Junkie

gone for now
looking at bikebandit, the complete head is the same for 09-12 ST and STR

apparently the Daytona heads can be used, but have a different shape exhaust port and I guess require a different exhaust
 
J

Junkie

gone for now
given the cost of parts I don't think it's worth trying to repair that engine: a piston is >$250, add in the gaskets and various other parts and you'll have quite a bit of money into it
 
295566

295566

Numbers McGee
As others have said, junk. Get a good used one and call it a day. I'm also wary that the cylinder wall isn't fuxored; that metal had to go somewhere when it got chewed up. Not worth the risk of grenading a second cylinder head/engine block.
 
ST Guy

ST Guy

Well-known member
The head is junk.

What does the cylinder wall look like?

Also, it's entirely possible little metal bits went places they shouldn't. You're looking at a complete engine tear down and rebuild, checking everything and leaving nothing to chance. If you have the time and money, it can be a fun experience. But my recommendation is find a good used engine.
 
afm199

afm199

Well-known member
Based on the pics it will be a miracle if the cylinder wall is ok. That valve head bounced around in it long enough to hole the piston. Also, the cylinder is almost certainly Nikasil, which means sending the block out and paying $600 to have it fixed and relined. Nobody uses cast iron liners anymore. And, as mentioned, there's pflug in the cases that went everywhere. I have torn down a couple of those. It's toast. Forget it.

Have you ever rebuilt a motorcycle motor? It's not exactly like a lawnmower.
 
mototireguy

mototireguy

Moto Tire Veteran
With enough beer and money anything is possible.

Head kaput.

Engine case/cylinders good with one caveat, that bad cylinder wall will need a very close inspection that there's no bad scratches.
 
kuksul08

kuksul08

Suh Dude
The exact same thing happened to my friend's 2014 STR at 60k miles. Traded it in on a new one. Triumph wouldn't do a thing.
 
S

self_moto

Well-known member
afm199 said:
Based on the pics it will be a miracle if the cylinder wall is ok. That valve head bounced around in it long enough to hole the piston. Also, the cylinder is almost certainly Nikasil, which means sending the block out and paying $600 to have it fixed and relined. Nobody uses cast iron liners anymore. And, as mentioned, there's pflug in the cases that went everywhere. I have torn down a couple of those. It's toast. Forget it.

Have you ever rebuilt a motorcycle motor? It's not exactly like a lawnmower.
Click to expand...

Thanks for info(now YouTube suggests videos about Nikasil :laughing. )!

Added cylinder pics, there is a minor damage but I believe you can replace that sleeve only.

I look at this engine as a project and opportunity to learn how to rebuild one, I’ve swapped engine on bike last year(10k since swap), so there is no rush in fixing it, so to speak. Just gathering information, before deciding to do it or not.
 
afm199

afm199

Well-known member
self_moto said:
Thanks for info(now YouTube suggests videos about Nikasil :laughing. )!

Added cylinder pics, there is a minor damage but I believe you can replace that sleeve only.

I look at this engine as a project and opportunity to learn how to rebuild one, I’ve swapped engine on bike last year(10k since swap), so there is no rush in fixing it, so to speak. Just gathering information, before deciding to do it or not.
Click to expand...

If it's Nikasil you don't replace sleeves. You send the block in to a place like Millenium and they bore it out ( it's a small amount maybe .003", and then electroplate the liner back in, and rebore it and hone it. I don't think they do the inline fours one cylinder at a time. I think they only do all four. If it is one, it ends up about $350 ($250 for one plus $50 shipping each way), or all four $500-$700 or so plus shipping. The last two times it has cost me about $600. But I don't do them any more. I just buy another block.

Looked at the pics, that cylinder is gone. Looks like Nikasil.
 
Last edited:
ST Guy

ST Guy

Well-known member
Cylinder is buggered. And more than 0.003" worth.

Get yourself a running engine and if you want to, take it apart and freshen it up.
 
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