View Full Version : Pics of my blown internals, questions.

04-10-2007, 07:09 AM
I blew my motor last year and just now finally took it out. I took some pics of the internals. I lost the ringlands completely on pistons 2 and 3, and cracked it on 4. The rings were cracked on 3 and 4. I spun all 4 bearings I think, and got rod knock on 3 if I am reading this right. I there were no signs of detonation (pitting on pistons or head). But the exhaust valves on 2 and 3 seem burnt up at the edges, what causes this?

Now I am curious as to what came first the spun bearings or the cracked ringlands (what blew up). It blew boosting on the highway one night. I felt something wierd happen and noticed a change in exhaust note. If I pushed in the clutch it would die, I was less than a mile from home so I though I would get it there and check. Got off the highway and a couple blocks from home I started hearing rod knock. When I drained the oil the next day there was only about 2 quarts in there.

2 and 3 piston.
Rod journal 2 and really bad 3.
The really bad set is no. 3.
Cyl. 2 is the only one with scaring.
What caused my valves to look this way?

04-10-2007, 09:17 AM
spun bearings are usually a dead give away of the motor getting way to hot. see that black line in the middle of the bearings? i bet it looked like that under them on the rods and mains too right? where the bearing very loose when you took them out (bearing notches not in the saddles?)? that's where oil has started to burn and over heat in between the bearings and the caps. how often did you change your oil? also how long did you have your foot in it that night? it doesn't look like something that happend over night but from alot of abuse.

04-10-2007, 11:14 AM
sounds like you lost the rings first when you mention diff exhaust tone and then it wouldnt run with the clutch pressed in.. do you have a boost /vacuum gauge? how much vacuum was the engine pulling when you first noticed a change in exhaust/driving home? what mods are done to the engine? Looks to be detonation how much boost were you running? I lost the ring/ringlands on my number 3 piston about 3 years ago now... seems alot of people have problems with that cylinder. anyways I know the cause of mine. . .SAFC 2 now in garbage. . .and there is an aem ems in my car. . .I wont state what shop did the work and thought an safc2 with a t2 flanged gt3071r @16psi would be fine with a stock ecu. . :mad: well after much time, knowledge , and money I know better and do all work myself. I would consider just buying a longblock if your not planning an extensive build you can get one for like 800 plus shipping. good luck

04-10-2007, 12:42 PM
Detonation!!! FTL

04-10-2007, 04:53 PM
I don't know about detonation. Look at the quench areas. I don't see the tell tale pits in the quench areas. Then again, the head is not clean, and you can only see a portion of one cylinder.

You can check to see if the valves are sealing by pouring some water into the exhaust ports. If it comes out, then the valve is not seating.

Judging from the pictures posted, and if the valves aren't seating, I would say that you were a bit too lean.

04-10-2007, 06:12 PM
Thanks for the replies guys. I was just curious, I had had this thing on the dyno a ton and the air fuels seemed to be good. I was only running 370s though, maybe that night I overboosted a bit and maxxed out the injectors and caused it to lean out. This is on a 97 KA-T with an Emanage with ignition harness.

I bought a really clean motor out of a 93 that I am going to build. I have essentially the Turbo240.com Advanced rebuild kit that is going to go in that. And now that the head is bad I am going to put in stainless valves and new springs and retainers.

04-11-2007, 02:33 PM
Does anyone have reccomendations on valvetraing components? AMS sells the Supertech stuff, but I have a friend that reccomended Ferrera components. Is there an advantage to one over the other? I am debating changing the valve guides what do you guys think? I know that sivalves.com (http://www.sivalves.com/ocforeign_vguides.html) sells bronze valve guides is that a worthy upgrade over whatever the stock material is? I also bought a full Fel-Pro gasket set and it came with Viton valve stem seals, are those good enough to use?

What about main and rod bearings? AMS sells both Clevite 77 and Calico Coated ACL bearings. Would I be better served by getting the clevites and sending them to Swain Tech for coating when I get the pistons Gold Coated and PC-9ed?

I am trying to make this a very efficient motor (most power at least boost possible). I plan on using a Full-Race manifold or perhaps the one from GroundZero Motorsports. What else do you guys reccomend for efficiency?

04-11-2007, 02:37 PM
More pics showing combustion chambers lack of pitting. the marks on the top of the piston and that one head were me scraping the carbon buildup.

Here are some pictures of the motor that I bought to build:

And here are some of the parts that it is getting:

04-12-2007, 08:39 AM
Detonation, ring lands don't magically break. Reuse the stock valves if possible, there is nothing wrong with them, sodium filled exhaust valves are better then inconel, Cosworth used inconel on their F1 engines, had problems and solved them with sodium filled exhaust valves. Note, Cosworth made the most power in F1 last year with 5% of some teams engine budgets. Put the money to good use, have Pro Port port the head, buy some stiffer valvesprings, new guides and seals, rebuild the bottom end, metal head gasket, new OEM headbolts or 1/2" studs, and use good gas/race gas next go-round or maybe resort to the water/meth bandaid.