I am interested in knowing if anyone has blew their motor using these cams. I have heard numerous stories from peeps about this wondered if the cams had anything to do with it. I know the skunk2 stage 2 has higher duration than the Jun Type 3 cams by comparison. Post any knowledge you have regarding this issue.

 

If somebody blew their engine with the stage 2's I would almost be willing to bet $$$ that they didn't use the advised upgraded valve springs, which led to coil bind and broken parts.

Austin

 

please be sure it was the cams before posting a topic like that. If i was a skunk2 head id be pissed.

 

How about some more info on your setup.

 

Turbo/nitrous/X brand cams don't blow motors.

PEOPLE blow motors.

kthx.

(99% of the time anyway. )

 

need more info to help ya out. i doubt the cams blew the motor tho

 

I agree, you must have the appropriate hardware to use any (most)aftermarket camshafts...

 

It also depends greater on how the assembly was done on the cam caps. If they are over torqued, then yes the cams will break. Even the stock cams will break if you dont torque them down properly.

 

no offense, but it sounds like the rest of your valvetrain wasn't up to par. what else did you have, springs etc. what rpm did they snap? were they broken in, especially with some assembly lube? lets hear some specifics.

 

The cams didn't blow it, poor planning blew it. You must upgrade the motor to accomodate your upgrades. The valvetrain is a system; upgrading just one part places much more stress on the rest of the parts. Plan and research what you're gonna do before just throwing parts into your motor.

 

Sorry, I should of listed my whole setup before posting that message. I have a b20vtec with the following:
1. Skunk2 [stage2 cams, cam gears, dual vavle springs, titanium retainers, intake manifold]
2. JE (11:1...stock bore) pistons
3: DC 4-1
4: AEM bored gsr throttle body
5: Stage 3 head job by KG engineering
6: SI stainless steel valves
7: RC 440 injectors
8: S200 hondata with P72

and what happened was I punched the engine right up to (9000) redline and POW! the egine shut off.

NOw here I am a pedestrian for the meantime...

 

One more note...I didn't mean to offend anybody that uses Skunk2 or is a fan of theirs. Sorry if I did.

 

People build LS/VTEC's, rev them past 7k, blow them, and then wonder what happened.......

Just to make your quest for knowledge easier, it wasn't the cams; the motor popped from being revved too high.

 

9000 RPM killed it. That the cams let it breath up there isn't their fault. Who told you that a B20 bottom end could be rev'd to 9k safely?

 

Did you upgrade your valvetrain when you went to a bigger cam???

 

I don't know what duals he used, but none of that matters. He hasn't said what the engine damage is but you can be relatively sure it's the 9000 RPM that did it.

 

It's amazing how much people will buy for their engine and have installed but they have no idea what they are doing and what is going on with their motor. I bet his sleeves burst like a bubble at 9k rpm.

 

bad drivers/over agressive drivers , bad tuning, or faulty instalation blows motors....

 

the rotating assembly of that motor is meant from the factory to spin 6-7K MAX. what did you do to the BLOCK when you put that insane VTEC top half on it? Also, what made you think that the valve reliefs for that piston/valve clearance at 12+mm at 9K would work with the rod stretch/valve float that occurs at high rpm?
Have you broken down the motor yet and inspected the damage?
What Air/Fuel tuning goals were in mind when you built it for the type of rev band you wanted>
also... how far apart did you adjust your LCAs? Do you have adjustable cam sprockets?

 

revving an Ls/VTEC to 9k?!! wow...there's your reason right there. sorry about no havin a ride. hope ya got some cash to get it back on the road

 

There is quite a bit of preperation that needs to go into an engine that is going to be run up to 9000 rpm, you need to have your entire bottom end up to par, it sounds like your head was fine, but the block may have had some issues. You're going to have to pull the valve cover to see what the cams/springs look like, as well as the oil pan to take a quick look to see if you have metal fragments all over the place. More investigation would be needed to come to a conclusion as to what the cause for your blown engine.

The only local guy that I really trust is Lawrence at DynoSpot Racing in San Jose...

Austin

 

You said it just shut off? No clunking grinding or bangs? Shut off sounds like your timing belt broke, which wouldn't be all that unusually with that setup. The higher lift cams are tougher on belts. You'll hafta get it apart and have a look speculation is fairly useless. Good luck.

 

Thanks for all the different opinions. Apparently everyone is areeing, it is not the extreme duration of the cams that might of influenced the touching of the valves and piston. I did take apart the motor after that and the damage was isolated in the third chamber from the distribtor. The piston has a dime size hole through it and two of the valve heads broke off. Apparently the springs and retainers held up from getting a second opinion from a few people. The B20 block is okay but the head is really messed up, especially the third chamber.

I think i should also sleeve the b20 with a 84.5mm bore. Since the engine is apart right now.
Thanks for all the replies....

 

I don't suppose you used oversized valves? Skunk2 specifically warns against oversized valves on their stage 2s and 3s.

 

i know more than a few people who do that daily and have like 20xxx miles on their ls-vtecs.