What we said about your fuel mixture is NOT a theory.

Richen your AFR to the range we specified, and you can run as much ignition advance as it will take.

Where you are now leaves NO room for error. One small issue, and you will be replacing rods, pistons, and maybe the block as well. Run it long enough, and the chances are good that you WILL have an issue, especially if you are injecting methanol. We aren't recommending this because we are all stupid. We are telling you this for YOUR benefit. It makes no difference to us.

Just FYI.

 

First, I'd respectfully suggest that you go back and edit your opening post in CAPS to correct the mistaken information about a well known vendor's products. I frankly fail to see how you post that a rod failed and blew a hole in the block and then, after 4 pages of discussion about the reliability of a specific rod, discover that it was something else entirely. If you had looked through the "huge hole" in the block, I bet you would have been able to spot the rod intact. It's a tribute to the build strength of the Crower rod that it's still in one piece after the piston that it was attached to was destroyed.

Now that we've got that straight, tell us why you think "low tension" was the cause of your pulling the head off your valve. What springs were you using, and at what RPMs were you turning your motor at the track?

 

Stock springs and retainers.
I know it's not a theory, i'm just saying that in this case, it wasnt an AFR problem (lean). I respect almost every poster in here and always take the advises, so, i'll try a richer mixture, thanks.
First of all, i never tried to say that CROWER products are weak, or something else, i specified that they were crower rods to see if someone else had any similar problem or if that was the max output they can handle, just asking. I already said that in a past post.
Second, it was very dark, didnt had a flashlight and saw as much as i could. I saw a hole in the block wall, i assumed a broken rod, as the same thing had happened to other honda's and subaru's friends (Broken rods). Sorry, my mistake, but thats why i'm telling you guys wich the real problem was, for you to dont think that a crower rod can break to you too. In fact, i'm impressed that the rod is just a little bent and didn't broke after going through the block, still in one piece, as you say, thats a tribute to it's strength.
As i sad, the springs were the stock ones, also the retainers. The low tension problem was what the guy at the machinery shop told me, in fact, he ported n polished the head and have years in that bussines. Maybe low tension, valve floated and hit the pistons head.
BTW, redline was at 7500 RPM's
Thanks everyone.

 

What cams are you using?

 

264 intake 272 exhaust
Well, here are some pics

As you can see, the rod is in one piece, definately they are very strong



And heres is a pic of a piece of the piston that i found in at the end of the drag strip, the rest of it must be in the oil pan

No valve pics, the head will all the rest is at the machinery shop

 

That looks bad.

I don't recall seeing any similar instances with HKS cams and a 7500rpm rev limit, and there are *many* persons here with the same setup and no problems. Additionally, a piston making contact with a valve usually results in a bent valve.

Do you have a photo of the combustion chamber?

 

Looking at that made feel like there was a death in the family...

 

Sort of, LOL
Nope, the head is at the machinery shop. I know that in a normal scenario, these cams with stock springs at 7500 RPM's shoudn't had failed, but, seems i had bad luck.

 

Its the same BS I have had the endure 1,000 times over when someone posts misinformation regarding my product - then after the problem is discovered to be something completely different NO ONE is interested in reading about the real cause of the problem

Those who know crower and pauter etc know that those products just dont break unless there is another end user related cause

 

[QUOTE=got boost??]BTW whats the difference on the 6 bolt and 7 bolt???

Its a DSM thing. The early DSM engines had 6 bolts connecting the flywheel to the crankshaft. The later engines (the ones with crankwalk) used 7 bolts. So, when your engine failed due to crankwalk (and this happened a lot) you replaced it with a 6 bolt engine. DSM owners needed to have a high tolerance for pain.

 

A couple small corrections: (1) 7 bolt motors started in 93. The 93/94 7 bolt motors were very good. (2) The 95+ 2g 7 bolt motors were the ones that would occasionally crankwalk. It wasn't that common an occurrance. The 2g motors were modified by Mitsu, which seems to have solved the problem from that time forward.

 

[QUOTE=barneyb]Thanks a lot for the explanation.

Are you the owner of crower? You must be as your saying "My product".
Sorry if you're not interested into readding wich my problem was, but some other users did reply and gave me ideas of possible causes why my engine blew, instead of being flaming all the time, thanks to all of you. (I think that someone did were interested)
Sorry if in first instance i was wrong, but, i think everyone can make a mistake, even you. Also (once again), i never tried to say crower products were bad.
I always get good ideas and advises from this forum, and if i weren't interested to keep this forum a reliable information source, i wouldn't have posted wich the problem was, thats a proof for you that i'm not trying to say crower products are bad.

 

Dynoflash (Al) is a well known tuner who does ECU flashes. He doesn't own Crower.

I see you've changed your initial post that reported that the Crower rod broke. That was the right thing to do, and I'm sure the board appreciates it. The simple lesson for us all is that it's easy to make a mistake, post about it, and cause alot of people to have a inaccurate conception of the quality of a part. Many don't read the retraction later. That can be avoided if people confirm the facts before posting. Hopefully we've all learned that lesson. Then, good parts are not impugned and poor quality parts are identified, if they are at fault. Everyone can learn from each misfortune suffered by another Evo owner. I'm always interested in these posts, if only to learn as much as I can to avoid one, myself. Let's just make haste slowly in posting topic headings and posts that blame a certain part before that fact is confirmed...

 

You're right, i apologize for my mistake, but as you said, anyone can make a mistake, the important thing is to accept it, i did, thats why i changed the initial post just as an user told me to do, and he was right, it was a wrong information.
BTW, i'm impressed that the rod went through the block and didn't break itself.
Thanks everyone for your interest and once again i apologize.
And CO_VR4, thanks for your conpehension.
PD: is there an older and a newer crower rod generation??
Cheers

 

Your pictures suggest to me that you dropped the head of a valve into the cylinder. Your pictures show damage to the cylinder walls which are caused by (uncompressable) foreign object(s) bouncing around in the cylinder. There is not enough room for the engine to rotate to TDC with the valve head broken off in the combustion chamber. Something has to give -- either the cylinder head and/or the top of the piston. A hundred or so revolutions with the valve head in there broke the piston, and then what was left of it caught on the lower end of the cylinder bore and the crank powered it through the side of your block. That's my guess How does the combustion chamber for that cylinder look? Beat to crap? Missing a valve head? If it is, what caused it? Could be metal fatigue, but valve float is also a common cause, when the engine is overreved and the springs are not heavy enough to maintain contact with the cam. The valves get pulled up into the head by the spring after the cam has spun away from contact, and slam into the seat. After a few of those events the spring pulls the valve stem off the head, leaving the head in the combustion chamber. Can you get pics of the cylinder head?