Blew the motor

[Bird_Of_Prey]

Re: Blew the motor

quick question...if I broke a valvespring...would that cause a valve to smash the piston?

Very easily.

[LETZRIDE]

Re: Blew the motor

****...no I havent pulled anything apart, Im in the USA right now...I'll start maybe mon-tues when I get back....just trying to think what that loud ticking sound could be...and if i hit a piston with the valve, would I need to replace the piston? like I said, oil is very clean...im hoping I dont have to replace much more than a valve...Im not wanting to pull the whole motor all over again if I hit a piston....

[bigbrian442]

Re: Blew the motor

Loud ticking sound.... Loose rocker because the valve is bent.

[LETZRIDE]

Re: Blew the motor

well the only way the valve could bend is if it hit the piston...so if I've made contact with the piston, would that automatically mean I need to get new pistons? what are the odds I would need a new piston if we are talking valve to piston contact? can I order and replace just one piston? or would I have to have the block remachined?

[bigbrian442]

Re: Blew the motor

Chances are it put a nice mark on the piston if it hit it. You'll have to see how bad it is.

[LETZRIDE]

Re: Blew the motor

so should I possibly look into getting the abbott racing pistons? what is needed to run those, are they the same as the zzp ones? would I need L67/l32 rods? if there is no damage to the cylinder wall am I still looking at having to bore it out? because if I dont have to bore it, Im thinking that I could swap the pistons with the motor still in the car?

lastly, is a 10:3:1 compression ratio too much to run on the street with 91 pump gas?

[cam98aro]

Re: Blew the motor

so should I possibly look into getting the abbott racing pistons? what is needed to run those, are they the same as the zzp ones? would I need L67/l32 rods? if there is no damage to the cylinder wall am I still looking at having to bore it out? because if I dont have to bore it, Im thinking that I could swap the pistons with the motor still in the car?

lastly, is a 10:3:1 compression ratio too much to run on the street with 91 pump gas?

I havent really been following this thread, but usually the stock pistons should be fine.

are the stock pistons forged? if they are, i wouldnt even think about changing them unless one is damaged. If they are cast, or that hyperentuitic crap, and the "racing" pistons are forged, then i would swap them.

10.3:1 comp is getting a little high for pump gas unless you are planning on putting a wilder cam in it to get your dynamic compression ratio lower.. i have a sbc with 12:1 compression and I run a mix of 115 leaded/89 octane and it runs fine, although i have a cam with a pretty high duration so i can get away with it, total timing w/ advance is in the 42* BTDC range.

I have ran the same engine on pump gas but i had to retard the timing a lot to stop the pinging, and i never put a load on it.

if you want to run that compression with pump gas i would suggest getting a water/methonal injection kit, it will act like ~110 octane

[LETZRIDE]

Re: Blew the motor

I havent really been following this thread, but usually the stock pistons should be fine.

are the stock pistons forged? if they are, i wouldnt even think about changing them unless one is damaged. If they are cast, or that hyperentuitic crap, and the "racing" pistons are forged, then i would swap them.

10.3:1 comp is getting a little high for pump gas unless you are planning on putting a wilder cam in it to get your dynamic compression ratio lower.. i have a sbc with 12:1 compression and I run a mix of 115 leaded/89 octane and it runs fine, although i have a cam with a pretty high duration so i can get away with it, total timing w/ advance is in the 42* BTDC range.

I have ran the same engine on pump gas but i had to retard the timing a lot to stop the pinging, and i never put a load on it.

if you want to run that compression with pump gas i would suggest getting a water/methonal injection kit, it will act like ~110 octane

The pistons are stock from the 2005 L36, so they are not forged. The arh ones are forged...honestly, the only reason I was looking at getting different pistons would be because of a bump in compression...otherwise I'd be better off just ordering stock 9:5:1 pistons again. I dont think forged pistons really has any benefit on a N/A car, especially when I can get stock replacements from napa for 225$ over here versus 699$ for a forged set. (unless I am going to bump the CR, but if 10:3 is too high for a daily driver, and I would probably be closer to 10:5 by the time I rework the heads, its probably not worth it to get pistons, and just order some stock ones if need be...)

[LETZRIDE]

Re: Blew the motor

also, I should mention the overlap on this cam is 230/240 not sure if that makes much difference...

[cam98aro]

Re: Blew the motor

also, I should mention the overlap on this cam is 230/240 not sure if that makes much difference...

assuming thats @.050 i think you could run that higher compression on pump gas, your dynamic compression will be fairly low so I dont think you will have any problem.

[LETZRIDE]

Re: Blew the motor

assuming thats @.050 i think you could run that higher compression on pump gas, your dynamic compression will be fairly low so I dont think you will have any problem.

yes thats @ .050 ... is there anyway to know for sure? its a daily driver, so as much as I want to squeeze everything out of her, I cant risk not being able to daily drive it...

[cam98aro]

Re: Blew the motor

yes thats @ .050 ... is there anyway to know for sure? its a daily driver, so as much as I want to squeeze everything out of her, I cant risk not being able to daily drive it...

I wouldnt be worried running pump gas with that.. especially with the low timing these engines run

[LETZRIDE]

Re: Blew the motor

I wouldnt be worried running pump gas with that.. especially with the low timing these engines run

I also have the cam advanced 2 degrees if that makes a difference...and with the arh pistons and the heads milled down a little Im probably looking at 10:5...unless I countered it a little bit with a slightly thicker headgasket...but then I feel like I could just get stock pistons and run a .045 headgasket and be at 9:8 or 9:9:1 CR...

[cam98aro]

Re: Blew the motor

I also have the cam advanced 2 degrees if that makes a difference...and with the arh pistons and the heads milled down a little Im probably looking at 10:5...unless I countered it a little bit with a slightly thicker headgasket...but then I feel like I could just get stock pistons and run a .045 headgasket and be at 9:8 or 9:9:1 CR...

stock pistons would probably be the way to go.. why exactly did you want the higher compression? while its not a myth that higher compression will givve you more hp, it doesnt give as much hp as everyone says it does, if you are doing it just for the higher number, i would use the stockers and a thinner headgasket, no use in spending all that money for forged pistons (which btw will be heavier than the stock ones)

[LETZRIDE]

Re: Blew the motor

well although I have not taken the motor back apart...after all the reading Ive done on here, and google etc etc...my best guess is that I probably broke a valvespring in the new motor and bent a valve which means I need to replace atleast one piston and all my gaskets yet again (not even 3000km on the bloody thing) Ive been pricing some stuff out and Im debating that if higher compression pistons are only 200$ or so more, than I mine as well upgrade them if the stuff needs to be swapped anyways...right now Ive found out that I can get a single new piston for about 35$ but they only sell the rings in a pack of 6 and its like 165$...then I think I might need wrist pins as well...and maybe a rod? not sure...i dont know...honestly I just want to drive the f'n thing at this point. If I get the ARH pistons I get everything I need except for rods for $699...my best guess at this point for stock stuff is it will cost me 200ish + wrist pins...plus 174 for an mls headgasket...where if I go with the high cr pistons I would just go felpro headgasket

If I broke a 130# valvespring I dont know why the hell it broke...I dont think I will know either and I dont know what to think of that...makes me skeptical about whether or not that might happen again...maybe 130# is not enough for the cam which is 230/240 .512/.512 lift and 113LSA @ .050