The 2.1 is not new to the community. The old school DSM guys used the 2.1. It is simply a destroked 2.4 block. The advantage is you get your displacement from the bore size vice the stroke length. You ask why this is better? What limits the engine is with a longer stroke you are concerned about the piston travel in FPM, feet per minute. With the 2.1 the piston ahs a shorter stroke so your FPM is lower than the 2.0 and you can rev it a lot higher.

 

It is new to the EVO community. READ closer next time. You offer nothing. This has been beaten to death in many threads all over the place.

 

ahhh ...i was thinking of going this route but going with a bigger turbo.

 

Sorry I was just answering this question. You need to relax. I answered someones question with the technical data put in laymen terms so he could understand it. Sorry I have nothing to offer to you. As for Rez I hope I answered your question.

 

Once again....not trying to offend. But that was covered on the very first page of this thread on posts 10 and 12. READ CLOSER or try reading the WHOLE thread first.

 

hello, trying to offer some advice. What do you mean that the combustion chamber is damaged??? It has been my experience in building dsm's that the reason the rocker popps off is because the valve collided with the piston, bending the valve and not letting it go back to the seated position. This causes the space between the cam and valve stem tip(the part that touches the rocker arm) to increase and then the rocker falls out of place.
Now with that being said, if the rocker just "fell off" there would be NO combustion chamber damage because the valve would just stay closed and it would still have the other intake valve to run(probably poorly, but still run).
So what you should do is look closely at the valves, piston, guides.....something is wrong.(bent valve, hung in guide)....in extreme cases I've seen a rod bearing have so much clearance that the piston hit the head, anyway it definately does not happen for no reason.

hope my 2cents helps
-mike

btw nice engine!

 

I cant for the life figure out how it happened. The damage I am refering to is minor nicks from the piston as it came apart. I havent had the time (nor the tooling) to disassemble the head yet (it is off the engine I need a valve spring compressor). As of now I do not know if the valve is bent or not. I think I posted pics of the everything in a thread I started when the engine blew back in April. Searching under my name should show that thread if you are really interested in seeing the pics. Unless the timing belt slipped a tooth..I dont see how the parts could have made contact as the engine let go at around 3500-4k RPM. My AFR gauge showed a lean condition (I suspect the fuel pump) right before this happened. The crown of the piston broke off on the intake side so maybe they did contact. It is so hard to tell.

 

I hear that sentence is built better than SBR engines, though.

 

based on what?

 

I guess he thinks he can do a better job.

 

Sorry, I guess I shouldn't have been presumptive. Hope all goes well.