Piston wrist pins? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

jskateborders · 02-26-2008, 06:30 PM

How do you get them in. I assumed that light tapping with a rubber mallet would take care of the problem, But all its doing is fucking up the groove for the snap wring and going nowhere.
I feel like this is a question that should have been covered, but I didnt turn up any results with my search.
Sorry if it has.

Big Bronze Rim · 02-26-2008, 08:00 PM

Stop! You cannot bang the wrist pins in. The pistons typically must be heated for the pins to be a press fit. The OE pistons are this way as are some aftermarket ones. Your best bet is to take them to a machine shop and have them press them in. You could potentially do it yourself as per the FSM - heating the pistons to 140-158F in hot oil and then pressing them out, but its alot of trouble.

louisdaboois · 02-26-2008, 08:04 PM

if it's for a ka, you may just have the wrong wrist pins for the pistons. with mine, they fit snug. not a whole lot of clearance to wiggle back and forth, but just enough to let the rod move freely. the snap ring secures them. i'd double check that they're the right size before you hammer anything in man, best bet is to take Big Bronze Rim's advice and take it to a machine shop, they'll be more inclined to figure out if it's going to fit or not.

jskateborders · 02-26-2008, 08:25 PM

Its for an sr, its oem, I pulled them out. I was doing it via fsm, heated it to 145, Didnt go in. Went 160, got em in, burned the crap outta my hands. I guess next time someone searches, they will come across this. 160 got them in with some wiggle and pressure.
thanks for the help guys.

Big Bronze Rim · 02-26-2008, 08:30 PM

Good to hear!

02-26-2008, 06:30 PM	#1
jskateborders Zilvia FREAK! Join Date: Apr 2007 Location: Tucson AZ Age: 36 Posts: 1,258 Trader Rating: (5) Feedback Score: 5 reviews	Piston wrist pins? How do you get them in. I assumed that light tapping with a rubber mallet would take care of the problem, But all its doing is fucking up the groove for the snap wring and going nowhere. I feel like this is a question that should have been covered, but I didnt turn up any results with my search. Sorry if it has. __________________ "I am Norwegian, and are not familiar with your urban words :P"

02-26-2008, 08:25 PM	#4
jskateborders Zilvia FREAK! Join Date: Apr 2007 Location: Tucson AZ Age: 36 Posts: 1,258 Trader Rating: (5) Feedback Score: 5 reviews	Its for an sr, its oem, I pulled them out. I was doing it via fsm, heated it to 145, Didnt go in. Went 160, got em in, burned the crap outta my hands. I guess next time someone searches, they will come across this. 160 got them in with some wiggle and pressure. thanks for the help guys. __________________ "I am Norwegian, and are not familiar with your urban words :P"

02-26-2008, 08:00 PM	#2
Big Bronze Rim Zilvia Member Join Date: Jan 2006 Location: San Antonio, Texas Age: 46 Posts: 173 Trader Rating: (0) Feedback Score: 0 reviews	Stop! You cannot bang the wrist pins in. The pistons typically must be heated for the pins to be a press fit. The OE pistons are this way as are some aftermarket ones. Your best bet is to take them to a machine shop and have them press them in. You could potentially do it yourself as per the FSM - heating the pistons to 140-158F in hot oil and then pressing them out, but its alot of trouble.

02-26-2008, 08:04 PM	#3
louisdaboois Zilvia Addict Join Date: Dec 2006 Location: LA, CA Age: 36 Posts: 851 Trader Rating: (28) Feedback Score: 28 reviews	if it's for a ka, you may just have the wrong wrist pins for the pistons. with mine, they fit snug. not a whole lot of clearance to wiggle back and forth, but just enough to let the rod move freely. the snap ring secures them. i'd double check that they're the right size before you hammer anything in man, best bet is to take Big Bronze Rim's advice and take it to a machine shop, they'll be more inclined to figure out if it's going to fit or not.

02-26-2008, 08:30 PM	#5
Big Bronze Rim Zilvia Member Join Date: Jan 2006 Location: San Antonio, Texas Age: 46 Posts: 173 Trader Rating: (0) Feedback Score: 0 reviews	Good to hear!