Ke70, missfireing only when engine warms up

[allencr]

Done right = no rattle . Done wrong = valves not closing.

When the valve face wears and/or the seat recedes, the the lash closes up, when the lobe & cam & bearings & lifter/follower/tappet & pushrod & valve stem tip & rocker bush and its tips wear, or everything get hot, THEN the lash opens up.
What's Dad's warranty?

[Scoobzd]

When the valve face wears and/or the seat recedes, the the lash closes up, when the lobe & cam & bearings & lifter/follower/tappet & pushrod & valve stem tip & rocker bush and its tips wear, or everything get hot, THEN the lash opens up

.

And now everyones enlightened as to why u dont have a zero tolerance !

Cheers for that allencr

20,000ks or 200 beers - Customers choice !

from Dad

[river]

Hi,

And now everyones enlightened as to why u dont have a zero tolerance !

I didn't think anyone asked about zero tolerance. If you set the valves clearance in accordance to the engine manual, you will be fine.

What I was asking about was the reference, in your earlier post, where you set the tolerance with "an everso slight amount of clearance because the valves are seating themselves with every closed action".

The factory manuals show the clearance that needs to be set. Do you set the valves "everso" more than the factory specifications?

seeyuzz
river

[toyboyracer]

Ok, Gordon here - Hiya everyone - Waving

After dicking around with cars since ummm... 1982 this is hard to explain - But I'll try

When using feeler guages a FIRM / SNUG / TIGHT feeling is the norm

When setting the valves a loose but not sloppy assed feeling is required - Makes sense ??

Guessing maybe .003 thou' is what I aim for UNDER the fact specs

"In time too you too my learn the ways of the Force my young Paduwan"

[TheToyman75]

Gordon,

If the feeler guage is sloppy when set to the correct feeler thickness for the setting you are trying to acheive, then the gap is to big and your doing it wrong.

Adding additional clearance ABOVE the factory spec will only result in reduced valve lift and hence reduced power, that sounds like an awesome idea

Adding .003 thou can also be quite a large percentage increase.

[toyboyracer]

Arrrghhhh.... Typing my point is so hard (grrrrrr )

As I tried to state, would you rather your valves be fully seated or NOT ?

If not then your compression will suffer = Waaaaay less power

In a perfect World we all would be running solid lifters = perfect seat and opening
(race motor apps) and this discussion would be a moot one indeed !

The feeler guage is a "feel" of how you use the tool

A really FIRM feel is how I set plugs = Damn tight

With valve clearances = Not so tight

As valves are ^ and are FOREVER seating and embedding themselves I go for a (sloppy) LOL

guagement to allow for this.

Making sense yet ?

Not trying to start a fight but I know where I'm coming from here

[MarkIIRx12]

Setting the valve clearance gap isnt really very hard, set it too tight and u wont get the feeler gauge out, set it too lose and u can slide in a 0.40 instead of a 0.30 wich is the factory specs for example.

I dont wanna drive around with a engine that rattles like a rattlesnake on meth, so i rather set it at perfect factory gap than sloppy, or too tight. In my opinon its not a easy thing to set that gaps too small/tight if u use a feeler gauge, like i said, u tighten it up and u wont even be able to pull the feelergauge out, and if u get it out, u sure as heck wont be able to slide it back in.

Its like a breaker point, if its 0.45, u dont want 0.50 or 0.40, u want it at 0.45, its nothing in between. (unless its a specific reason u want it higher or lower of course)

Maybe im just picky about setting the gaps here and there, but thats my way i guess

[toyboyracer]

rattlesnake on meth

would be a Mazda 929 motor !

I think you get where I'm coming from Mark
(God I hope someone does !)

[MarkIIRx12]

Yes of course, its better to have too much clearance than not enough.

some years back a friend of mine set the clearances too small on a opel rekord 2.0L, vauxhall/holden or whatever u call it down in australia. After just a couple of days the crackshaft rod made a hole in the block the size of a fist . It was probably more things than just the valve clearance that was wrong with the engine tho, but u could hear the compression flowing thru the tappet cover and everywhere when the engine was running.

But then again, dont go for sloppy, go for perfect

[river]

Hi,

Gordon, I understand where you're coming from, but I don't get why you set the clearance more than factory spec - even if it's just a "fraction". The valves "seating and embedding themselves" shouldn't be an issue.

The exact factory specs are perfect for the engine and that's what the valves should be set too.

However, if you find setting them slightly more works for you and the engines, then that's cool.

seeyuzz
river

[MarkIIRx12]

Hi again

I did the compression test today, and it seems very good. Every cylinder had compression on 11.5 bars. Kinda confusing tho since the manual says it should have 9 ?

I also set them timing perfectly and the car got a lot more power, even at higher rpms, but valve floating still happens at 6300rpms, a lil low isnt it?

Will adjust the carb later today and hopefully the engine is good to go.

[Scoobzd]

I'll get a friend who works here a Toyota to see what sum shiny new valve springs will cost !

If cheap enough will post them over to you ASAP !

[MarkIIRx12]

Hi

Thanks a lot for the offer, but i just got off the phone with my local toyota dealer and they said i could get the new ones for 30 bucks for a set of 8, just to clear out their inventory for old parts. I also got a clutch release bearing and some other stuff for like half the regular price

Thanks a lot for offering tho, would have been very usefull, i appriciate ur help

[Scoobzd]

Excellent score there !

The buzz box will now redline @ 6700rpm

[MarkIIRx12]

Yet another question

Wich way do i screw the mixture screw to make it run leaner? is it in or out? im using a vacuum meter to adjust the carb, but its a pretty big area where the vacuum is on top, and i want it to run as lean as possible, so is leaner screwing it out or in? i never remember wich way it is.

Thanks again for ur help