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Kingcab

L20b 86mm pistons

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With the stock headgaskets there is no overlap over the cylender walls with the 86mm bore at least with whatever brand I am using I will specify the brand when I get off work later.

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Yeah, you can't reuse a head gasket. It's crushed when torqued down and you can never get it exactly in the same place and seal. 

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But now I can't figure out why from idle if i floor it it has a huge hesitation and if I don't let off the gas it backfires out the card and dies

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With the stock headgaskets there is no overlap over the cylender walls with the 86mm bore at least with whatever brand I am using.

Well that's good....

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Figured it out!!! Not sure what it's called but it was part of the choke on the weber I was using. The piece with the blater on it was broken. Replaced it and tuned it and it runs better than ever!

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Figured it out!!! Not sure what it's called but it was part of the choke on the weber I was using. The piece with the blater on it was broken. Replaced it and tuned it and it runs better than ever!

Gotta luv it.... atleast it's fixed...

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Right I Stoked I finally figured it out! I was wondering the best way to break in new piston rings and fresh bore.. also what oil is best to use??

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Oil anything with the high zinc... guys here like the rottella I believe.... I actually went the royal purple route they offer a HPS high zinc and phosphorus oil..

 

As far as break in the rings hasn't it already been running?

Basically now just drive it....

I actually broke my motor in on a dyno and all we did was a couple pulls to 2000, let the motor compression settle it back to idle then go again with a bit more rpm, but I was also breaking in a cam and stuff too.... once done I was making pulls to about 5500 ....

If your running and driving just go for a cruise vary the rpm and let the motor compression slow the vehicle and you'll be fine....

I'm sure I'll be corrected if someone disagrees...

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I'll add this... I used a break in fluid when I did mine... some say use the oil your gonna run but that choice is yours...

 

Also found this info....

 

Screenshot_20180104-070654.png

 

Screenshot_20180104-070612.png

 

Screenshot_20180104-070721.png

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DRIVE it. Keep eye on temp and water/oil levels. Don't let it idle for long periods or maintain the same speeds and vary the acceleration and load on it. Make it do some work. Acceleration under load forces the rings against the cylinder walls and this wears them together and improves the seal that holds the compression in. 

 

A 'break in' oil just causes accelerated wear to speed up the process, but I would never use it. Easier to just drive it. Yes use a high content ZDDP oil like 15w40 Chevron Delo 400 or Shell Rotella T4 or any marked racing oil. I'm not a fan of synthetic oils they are over priced and their protection more than you need.

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When should I do the first oil change after break in?

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Did you not read what crashed posted?

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Okay thanks for all the info guys I'll keep you guys!! Really helpful!

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So I use beak In oil for every oil change till about 4000 miles or more? Right and also very rpm sand load?

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Sorry if I sound dumb but I'm completely new to all this and want to make sure it's done right!

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I dont blame you for being cautious... last thing you wanna do is undo everything you just accomplished..

People will always have varying opinions on this...

But I was told by royal purple that I could leave their break in fluid in till 1000 to 1500 miles, i have already changed the oil filter once just after initial break in just to make sure all was good. Good idea to open the filter up and look for excessive metal after, lucky for me all was good there too... i plan on changing the filter again at 500 but leaving the break in oil in, and at 1000 miles I will do a full oil change ... so i probably wouldn't use the break in oil till 4000.... 500 or a 1000 should be fine.

The biggest thing is make sure use a break in oil with high zinc and phosphorus.. if you cant get that just go with the rottella like mike said..

Also use a quality filter like bosch or wix... fram sucks, stp is questionable...

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STP is a FRAM filter.

 

 

Go to NAPA and get their filter. Or a WIX.

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STP is a FRAM filter.

 

 

Go to NAPA and get their filter. Or a WIX.

I thought that was the case with stp I knew people didn't like the fram didn't remember why the stp wasn't liked....

And It does seem like there are no complaints about the wix brand, yet....

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If you change on time and have a good running unmodified car fram will work, but for the price there are much better quality out there for piece of mind.

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If you change on time and have a good running unmodified car fram will work, but for the price there are much better quality out there for piece of mind.

This is what i told people during my years in auto parts. If you're really good at maintenance, the basic crap is likely fine. But if you are a ANYTHING but perfect about maintenance, just get a WIX.

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I went with the 15 40 oil. I was using delo 400 i think... for the first 50 miles. Engine seems to run and idle a lot better with the 15 40 in it.

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You say don't let it idle for to long?... it is winter time how long should I let it worm up? I've been driving the rebuild for about 3 days now and I let it idle for about 5 minutes before I drive it is that to long??

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I'll add this... I used a break in fluid when I did mine... some say use the oil your gonna run but that choice is yours...

 

Also found this info....

 

Screenshot_20180104-070654.png

 

Screenshot_20180104-070612.png

 

Screenshot_20180104-070721.png

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