Toyspeed.org.nz Message Board

by **matt dunn** » Fri May 19, 2006 11:39 am

After some info if anyone knows or still has some pistons with the rods attached.

The rods have a wee hole on the outside near the big end which I presume squirts oil out from the bearing.

What I want to know is does it squirt to the intake or exhaust side of the block?

Been so long since I pulled these engine too bits that I am not 100% sure anymore?

Matt

by **Grrrrrrr!** » Fri May 19, 2006 11:56 am

Club4ag tech section says Intake side. I'm heading out to the workshop now and i'll check the 20v i have in pieces if i remember.

by **Mr Revhead** » Fri May 19, 2006 11:59 am

using logic i deduce that it is the intake side

by **matt dunn** » Fri May 19, 2006 1:37 pm

Mr Revhead wrote:using logic i deduce that it is the intake side

Thats what I though as I think the load will be on that side,
but am lokking for a 100% positive answer.

Matt

by **Mr Revhead** » Fri May 19, 2006 1:45 pm

well i decided that as the squirters are on the exhaust side...
so i figured they wouldnt have oil squirted on the same side twice....

by **matt dunn** » Fri May 19, 2006 1:53 pm

Mr Revhead wrote:well i decided that as the squirters are on the exhaust side...
so i figured they wouldnt have oil squirted on the same side twice....

They actually squirt up under the piston, not onto the bores.

This ones squirts directly onto the bore.

Matt

by **Mr Revhead** » Fri May 19, 2006 2:20 pm

yep, but youll still get splatter etc onto the bore
especially as its a constant stream....

by **CAMB01** » Fri May 19, 2006 7:22 pm

The oil holes on the side of the rods always go on the right hand side, or the intake side. As the engine is firing the piston is forced down and load goes against that side of the cylinder, so needs lubrication

by **Grrrrrrr!** » Fri May 19, 2006 8:10 pm

Matt, had a look at the silvertop i pulled apart the other day and can confirm that 20v rods have the oil hole on the intake side.

Interesting how they deleted the oil squirter holes on the blacktop rods. (according to Club 4AG). Looking at the silvertop bigend bearings i'm wondering if that hole allows too much oil pressure to escape exactly where it is needed most.. when the piston is being forced down hard on the power stroke.

Might consider filling the hole with epoxy when i rebuild the motor. The oil squirters and the oil thrown from the crank should provide enough lubrication and cooling.

by **AceSniper** » Fri May 19, 2006 8:37 pm

blacktops have a small grove cut on the out side face to send oil up like the squirters

by **AceSniper** » Fri May 19, 2006 8:43 pm

(http://www.billzilla.org/4agmods3.htm)

"4AGE con-rods. Note that in the photo on the left the rod on the left has a groove cut into the side to squirt oil up onto the bottom of the piston to cool it, while the one on the right has the conventional small hole. They both end up doing the same job, though the one with the slot would tend to help cool the piston more and also make the rod a little stronger. Both rods have a small hole in the little end to also help oil lubricate the gudgeon pin."

by **Grrrrrrr!** » Fri May 19, 2006 8:56 pm

Hmmm, very interesting. Pity they dont note that on the Club4ag tech section.

Those blacktop rods are thin... i see now why 9k rpm isn't a good idea on them

by **Mr Revhead** » Fri May 19, 2006 9:19 pm

for what its worth silvertops are not known for running bigends (when looked after!) so i dont think that hole is an issue

by **crnkin** » Fri May 19, 2006 9:51 pm

the only 4ages ive ever pulled apart with banana'd crank shafts and 4 worn bigends have all been silvertops all with less than 120kms. I thought they were well known for blowing bigend bearings?

You always see people selling 3 on tardme, but i suppose that could be put down to lots of people "not looking after them"???

by **Mr Revhead** » Fri May 19, 2006 9:53 pm

iv heard of far more blacktops dying due to rods failing than silvertops running bigends

by **Grrrrrrr!** » Fri May 19, 2006 10:02 pm

I sorta figured that, the motor had 174K kms on it (plus jap import windback allowance), and with me abusing* it for the last 90,000 of them the fact it was still running is a good sign. Only thing i noticed was that around that hole is where the bearing shells are showing some minor wear. they look like they'd be good for another 175K kms.

* has seen 9.5k rpm.. even with a rev limiter that kicks in at 8250.. downchanging into third at 165 is not recommended. Could be why i'm on gearbox number three. hehe.
Also has enjoyed more than a few sustained speedlimiter runs (On closed roads of course).. back when fuel was cheap, and other miscellanous methods of mistreatment.. revlimiter on a cold motor, clutch kicking in the wet to see how long i could keep the single spinner going (800m for the record, and on reasonable rubber

)

by **crnkin** » Fri May 19, 2006 11:25 pm

Mr Revhead wrote:iv heard of far more blacktops dying due to rods failing than silvertops running bigends

Ohhhhhhhhhhhhhhh right right right yeah i get ya

I meant 16 valves compared to silvertop, no blacktop has been as unfortunate enough yet to get my dirty hands on them yet

by **Mr Revhead** » Sat May 20, 2006 9:38 am

yeah any 4age will run bigends if thrashed and not keep topped up with oil!
as they only hold 3ltrs in the sump they can be prone to it. especially the bigports as they dont have the drain from the head like the later ones do

by **AceSniper** » Sat May 20, 2006 6:15 pm

yea awhile back quite afew silvertops had run bearings.... due to low oil level... silly people...

While Blacktop rods throw holes in blocks with out warning

by **AceSniper** » Sat May 20, 2006 6:20 pm

Grrrrrrr! wrote:* has seen 9.5k rpm.. even with a rev limiter that kicks in at 8250.. downchanging into third at 165 is not recommended.

you can hit 160k in 3rd at 9k on a c56

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