james610 Posted May 13, 2013 Report Share Posted May 13, 2013 havent been on here in a while but i just bought a 72' 521 w/ a L20b that came w/ oversized pistons that i need to install. i am planning on installing the pistons/rings the privious owner purchased & replacing bearings, waterpump, & oil pump is there any thing else i should replace? they are ACL pistons, any good? new piston dimentions: type: RA2656 oversized: 0.75 recommended clearance measured @ bottom: 0.025 i attached a pic of the head, is it a stock l20b head? heres the piston tech sheet: Quote Link to comment
dattoboy70 Posted May 13, 2013 Report Share Posted May 13, 2013 what is the casting number on the side of the head? also, you can replace your oil pump with one from a ka24e it is a high volume oil pump Quote Link to comment
james610 Posted May 13, 2013 Author Report Share Posted May 13, 2013 not sure i can check tommorow, wat is it suppose to be for a l20b? Quote Link to comment
Dawa Posted May 13, 2013 Report Share Posted May 13, 2013 from that photo we cannot tell if that head 'came with' the l20 or not. if you showed us the underside of it and/or the number on the side of the head, then we can tell. pretty much you can use any head on any of the 4 cylinder Ls, but some will raise or lower compression give all the oil and water passages a good cleaning. clean all thread holes, especially those for the head bolts. Quote Link to comment
james610 Posted May 13, 2013 Author Report Share Posted May 13, 2013 ok a post a pic tomorrow... also wat kind of power increase should i get expect w/ the new pistons? Quote Link to comment
banzai510(hainz) Posted May 13, 2013 Report Share Posted May 13, 2013 expect w/ the new pistons? like a new motor from factory thats it. watch this a few times eating Cheetos.be careful wakeing up with orange weiner is the morning is common. so no need to see the Doc. 2 Quote Link to comment
Dawa Posted May 13, 2013 Report Share Posted May 13, 2013 yeah, i watched hainz' videos a few times, as has the majority of the forum, very helpful Quote Link to comment
james610 Posted May 13, 2013 Author Report Share Posted May 13, 2013 stamped on the side "nissan japan w58" Quote Link to comment
izzo Posted May 13, 2013 Report Share Posted May 13, 2013 Maybe read it wrong? Probably W58? Quote Link to comment
james610 Posted May 13, 2013 Author Report Share Posted May 13, 2013 yea sorry it is w58 Quote Link to comment
izzo Posted May 13, 2013 Report Share Posted May 13, 2013 Smog head. If you're going to dump money into a head, I'd pick a different one than that.. Just my .02 tho. even if you're just going to slap one on and run it, id still pick a different one. Quote Link to comment
Eagle_Adam Posted May 13, 2013 Report Share Posted May 13, 2013 X2 - thats a smog head, plenty of other cheap ones that perform better Quote Link to comment
banzai510(hainz) Posted May 13, 2013 Report Share Posted May 13, 2013 Nothing really wrong with it/ Its a smog l20 head. its a round port exhaust. Did the exhaust lead around the exhaust manifold, Why I ask is the stock 521 is a square port Quote Link to comment
james610 Posted May 13, 2013 Author Report Share Posted May 13, 2013 if i get a new head wat do u guys recommend? not really trying to put to much money into it right now tho.. thank sfor ur imput... Quote Link to comment
Dawa Posted May 13, 2013 Report Share Posted May 13, 2013 a new head can be had for cheap. i suggest you do some research yourself into the different heads and their positives & negatives, unless some kind soul comes in here and gives that info to you. but the point is to eventually work yourself up to be self sufficient. the problem with switching to another head is that if the exhaust ports are square, then it would obviously be BEST to run an exhaust manifold with square ports as well. which means you would have to spend money on an exhaust manifold. if i were you, i feel the smartest thing to do would be to run with the head you currently have, (dont even rebuild it,) source another, used head, rebuild that and also source an exhaust mani if needed. Quote Link to comment
james610 Posted May 15, 2013 Author Report Share Posted May 15, 2013 i have been work on my motor got everything pretty much together but i want to replace my water pump, every store i have tried only has a new water pump w/ a fan clutch, which i dont need, my current pump doesnt have a clutch... wat year & model car/truck comes w/ a l20b w/o a fan clutch? please let me know, this is the last part i need and i can drop my motor in.. thanks... Quote Link to comment
Dawa Posted May 15, 2013 Report Share Posted May 15, 2013 have you checked out rockauto.com? Quote Link to comment
james610 Posted May 15, 2013 Author Report Share Posted May 15, 2013 i'll look it up right now thanks Quote Link to comment
james610 Posted May 17, 2013 Author Report Share Posted May 17, 2013 just an update, dropped my engine in yesterday, i should have time to finsh today and have it driving.. 2 Quote Link to comment
banzai510(hainz) Posted May 17, 2013 Report Share Posted May 17, 2013 make sure that oil pump is primed Quote Link to comment
.sunlover Posted May 18, 2013 Report Share Posted May 18, 2013 ok a post a pic tomorrow... also wat kind of power increase should i get expect w/ the new pistons? Its a compression increase,we can only guess at the power, dyno tells no lies. About the head, show me its holes! (Intake/exhaust) and ill take a stab at a guess :) nah, I won't , but show me anyway, lol Quote Link to comment
james610 Posted May 20, 2013 Author Report Share Posted May 20, 2013 thanks... & yea its bagged... Quote Link to comment
james610 Posted May 20, 2013 Author Report Share Posted May 20, 2013 Its a compression increase,we can only guess at the power, dyno tells no lies. About the head, show me its holes! (Intake/exhaust) and ill take a stab at a guess :) nah, I won't , but show me anyway, lol i would send a pic but i have everything together so i cant take a pic Quote Link to comment
.sunlover Posted May 22, 2013 Report Share Posted May 22, 2013 i have been work on my motor got everything pretty much together but i want to replace my water pump, every store i have tried only has a new water pump w/ a fan clutch, which i dont need, my current pump doesnt have a clutch... wat year & model car/truck comes w/ a l20b w/o a fan clutch? please let me know, this is the last part i need and i can drop my motor in.. thanks... 1970 521 is what you want... Quote Link to comment
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