Topic: Need some guidance.

[YotaChris]

I am rebuilding the engine out of my 85 toyota and swapping it over to EFI but I am curious as to what pistons I should run or if there is a different set-up I could do that is better. I want to keep it street legal and use it as my daily driver but I want to bump up the compression and put a cam in it. I already have a new crank and some 4340 chromolly H-Beam rods. any help would be greatly appreciated. I heard that keith black pistons were good but I am unfamiliar with them...

[79coyotefrg]

get   aisin pistons,  you just cant beat the stock piston,  i have KB  but i went thru 3 busted pistons befor i finally got it right

dont go over .040  oversize bore

and get a  .430  lift cam  or  440,  i have a LCengineering .460 cam  but the smaller lift  will run the efi better

[YotaChris [OP]]

Thanks for the help. So stock is the way to go on pistons? No one out there makes a good reliable high comp. piston? has anyone ran wiesco? 

[79coyotefrg]

wiesco ??  oh hell yea,     i didnt realise  you had  your own oil wells 
last i checked  they was  well over $140 EACH
and  you would have to run premium gas  if  not  methanol

for a daily driver  dont go over 9.5:1 compression ratio,  thats  why  i suggested   the  "aisin"  piston  they are bulletproof

   most of  your power upgrades  are in the head



what  are you looking for  power wise??

[YotaChris [OP]]

Just more all around power so my truck will be a little more usable. Do I get the aisin pistons from a toyota dealership?

[79coyotefrg]

you can get them from napa  or  if  your using a  good machine shop  just have them  get  the oppropriate size

i assume  your  compression  was  low  ?  bad rings??    i HAD  to go to .060 over size  because  my block was  in kinda bad shape,   lost a exhaust valve at 6500 rpm 

[79coyotefrg]

I already have a new crank and some 4340 chromolly H-Beam rods. any help would be greatly appreciated. ...

  i  didnt see that part,  um   www.lcengineering.com  forged  but  tell them you want to be able to run pump gas,  you dont want  over 9.7:1  CR

[YotaChris [OP]]

no actually I rebuilt the motor like 4 years ago and just did a low budget rush job. It has good compression but I didn't mic. anything out and just put all standard busings and pistons in which left me with a little bit of a rod knock from the beginning but a few months ago it started to get worse so I parked the truck and am going to build the engine right this time. I guess I will probably go with aisin pistons. Do you know what the stock compression ratio is off the top of your head?

[79coyotefrg]

what year  are we  talking

efi  is  like 9.0:1  stock

[Cheesemaker]

9.2 seems to stick in my mind!   

But that is what they try to aim for, but if your close, who cares!

[YotaChris [OP]]

thanks, also why is it that I shouldn't go beyond .040 over? Is it because the cylinder wall will be too thin and risk cracking or is there another reason?

[79coyotefrg]

yea  its  starting to get thin at .060   ive seen  early 22R's  bored to .080  but  they ran  hot  if a v6 radiator  wasnt used


and  i have a v6 radiator,    that  should tell ya

[YotaChris [OP]]

Thanks I also have a v6 radiator already.

[79coyotefrg]

go .040   and  see if it cleans up nice,  if it does  pistons are easier to find  for .040

[YotaChris [OP]]

Will do. Thanks for all your help.   

[Jordan7118]

Really, you'll want to go as little on the overbore as possible. A machine shop will let you know. Mine was .030 over before they redid it. So I went with 0.040 over. The more you take now, the less you'll be able to take later if something craps on ya.

Glen's right. You'll get most of your power increase in the head. 0.060 over is really about the width of a couple hairs. Not much at all. If you really need more power, swap in a 4.3L chevy or if you want Toyota, put in a 2.7L late-model 4cyl or a 3.4L Toy V6.

Good luck with whatever you choose!