Roman's 4GR V6 Carina discussion thread

[yoeddynz]

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[Muncie]

Many years ago I did a stint at Woolf mufflers in Auckland the gun welder dude there had a trick for hard to reach spots on collectors.

Hard to explain, but figure out where the unreachable spot is in between pipes and recess in a flat plate and weld all the pipes to it, then when you weld around the outside of the collector its all sealed from the inside out to where you can access.

Short version of above make a ninja star and weld into the void inside pipes where you can't reach before pushing it all together.

It's saved me a stack of mig 3d printing over years.

[Roman]

Yep adding a little star shaped bit in the middle has been the plan.
Welding the collector itself wont be a problem.
I probably didnt explain it too well, what I mean is that when all of the pipes are parallel they slot in fine as they are hard up against each other. 
But when you get to the first bend, where its welded there isnt the same space anymore.
I could probably remedy this buy just buying the longer bends that have the straight parts as part of it, rather than needing welds at that point.

Now that I've got a design that works/fits, and looking at the shape that everything needs to be.
I think I could probably simplify the design to only a 3-4 pieces per runner if I bought some of the bends that have the long straight sections attached.

[shrike]

@Roman the stationary cooling system test vids don't seem to be loading :p

Bet your fizzing sounds nice and crisp love the intake noise

Great progress looking forward to seeing more graphs

[Roman]

Hah yeah still a few issues before I can do some skids.

It's looking like the gearbox has a leak on the front half which is annoying. 
It's a motor/box out job to fix that properly. Maybe there's a loose bolt or something but I'll have a better look on a nicer day.
I'll need to get the radiator properly welded too, my carbon fibre patch leaks a little when it's pressurized. 

So, some issues to fix but it also passed one of the tests today:



Valvetrain is still intact. haha.
I'll try get the car driving and/or to the dyno first before I push it too much more.
Lots of fiddly little bits to sort.

[Roman]

Spoke too soon, its dead again 
Well, while it was just running with a high idle it just started making a loud clattering noise so cut it off. 
Coincidentally I bought a bore scope camera today so stuck it down all the ports to see if anything interesting. 




So some debris has banged itself into the valve seat on one of the intake valves. Bummer! 
Not sure where this came from, as this is on the head where the valves bent previously.
So everything was disassembled, cleaned, checked etc. 

I'm thinking it's either bad luck of sucking something into the intake. 
Or there was a little piece of metal rattling around in the exhaust manifold, that got sucked back into the cylinder. 
Or maybe undoing the spark plugs and some debris fell down into it.
Might be able to identify what it is when I pull it apart again.

Not sure but either way if the valve seat is damaged then this head is a write off. 
So it's hard to know whether it's worthwhile carrying on with this motor, or just buy a whole new one. 
$150 for replacement head from PIckapart or $700 for a whole other motor from the wreckers. 
The oil got a little glittery from when the pulley blew up, so maybe it was on borrowed time anyway.
Either way, although this is yet again fucken annoying.
It doesnt stop me from progressing with a bunch of parts that still need doing.
 

[anglia4]

Maybe it’s cos it’s early in the morning… but I can’t quite understand how debris from a broken timing chain tensioner got into the inlet/combustion side of things?

[Roman]

I cant see how they're related either. 

Only thing I can think of, is if the debris under the valve then caused a bit of a jam on the pulleys or something. 

Or it's truly a coincidence and the timing chain stuff was just a timebomb waiting to go off. 

As the part that is bent on the exhaust pulley, is just something that holds the return spring in place. The pulley itself is still "fine" but that part is only pressed in place I think.
Might need to clean them up and tack weld them in place.

 

[Muncie]

You need to lockwire anything that shows signs of movement, at 9000rpm things are going to want to rattle loose.

Been looking at those cam gear parts that separated could you fit dowles? So the forces go through them and the bolts just hold everything together as future insurance.

Your probably 7 steps ahead of this already....

Gutted for you btw at least you got to hear it rev a few times.

 

 

[VitesseEFI]

1 hour ago, anglia4 said:

Maybe it’s cos it’s early in the morning… but I can’t quite understand how debris from a broken timing chain tensioner got into the inlet/combustion side of things?

Me either…… unless it’s made it through the breather system?

[yoeddynz]

17 hours ago, Roman said:

yeah still a few issues ...

has a leak which is annoying...

It's a motor/box out job to fix that properly...

I'll have a better look on a nicer day...

leaks a little ...

So, some issues to fix
 

I've just selected some of your words and it reads just like my project except for the 9000rpm bit

[yoeddynz]

The above was posted before I actually read and caught up with your latest shinnanigans.  Bummer!

But in true Roman dave form - this is a thoroughly entertaining read with many variables. You're just keeping us all on our toes with your destructive skills

[tortron]

1 hour ago, yoeddynz said:

I've just selected some of your words and it reads just like my project except for the 9000rpm bit

 

31 minutes ago, yoeddynz said:

The above was posted before I actually read and caught up with your latest shinnanigans.  Bummer!

Give the imp a few 9000rpm runs and you can be just like Dave!

 

 

 

(Factory imp engine will do 10500 rpm all day)

[Roman]

Probably more, didnt you know its an f1 engine? 

[yoeddynz]

47 minutes ago, tortron said:

Give the imp a few 9000rpm runs and you can be just like Dave!

....double checks ecu settings, rev limiter still set at 6500 - phew!

[Roman]

3 hours ago, Muncie said:

You need to lockwire anything that shows signs of movement, at 9000rpm things are going to want to rattle loose.

Been looking at those cam gear parts that separated could you fit dowles? So the forces go through them and the bolts just hold everything together as future insurance.

 

So turns out that there's a youtube video about this exact problem and a proposed fix.
 

 

[ajg193]

The Car Care Nut has a long video going over the achilles heels of these engines. If I recall correctly Toyota made changes over the years and you can tell which revision (newer =  better) it is just by looking down the oil fill hole.

[Roman]

You're right this guy is smart 

[anglia4]

9 hours ago, Roman said:

Only thing I can think of, is if the debris under the valve then caused a bit of a jam on the pulleys or something. 
 

ah yeah that makes a bit of sense. Thinking if the cause and effect the other way around.

It will be interesting to see if you can work out where the chunk of shit came from to begin with.

[Roman]

No idea but the only things I've had near the motor that I could have dropped in, would be washers or small bolts which wouldnt have ended up that shape.
I ended up sucking it up the spark plug tube with a vac cleaner so didnt get to see any better what it was.
I just recentlyish had my front yard dug out for a pad for a garage and new driveway, so might have been a bit of gravel that got in there somehow. 

However after reading some more about exhaust pulley failures I'm increasingly thinking that the exhaust pulley situation was inevitable regardless.
So, sucks it happens but then also it's better here and now than half way around a race track or 100km from home.
I think I'll do similar to that video above, and make some retainer cap type things to stop the press fit part from popping out.

What is annoying is I had 3x spare pulleys that I pulled off when I replaced them, that I only just chucked out a day or 2 ago. 
Would have been handy to have one spare out of the car right now.