Another engine rebuild...

shnazzle · March 21, 2016, 11:41

Quote from: "jonbill"Update on this:-
Carolyn came round on Friday with a compression tester & more.
Compression was good - 185 to 190 PSI so no HG problems. Carolyn said that's above OEM figure, so indicates some oil getting past the oil rings.
I went for a long drive to dry the exhaust packing. It was still smoking at the end of that, although when I rev it now there's a distinct blue tinge to the smoke.
It smokes strongly after overrun - which I think indicates valve guides/stem seals. Carolyn suggested PCV valve could also cause this, esp. since it doesn't smoke at cold start.
So.. I'm currently awaiting a new PCV valve and we'll see where that gets us.

Excellent to see members helping out physically! Nice one.

Hope the PCV solves the issue, at least partially. Then deal with rings.

Carolyn · March 21, 2016, 13:54

I'll be interested to see how it turns out. Though I suspect Jon just wants to tear into another engine anyway, 'cos he loves that stuff. He's got a great Datsun. (Proper car).

jonbill · March 21, 2016, 16:43

Thanks for all the help & advice Carolyn, much appreciated.
btw, are your tyres NS2 or NS2R? I bit the bullet and ordered 4x NS2s for the Datsun. £150 for 4 worth a punt (205/60/14).

Carolyn · March 21, 2016, 17:06

Quote from: "jonbill"Thanks for all the help & advice Carolyn, much appreciated.
btw, are your tyres NS2 or NS2R? I bit the bullet and ordered 4x NS2s for the Datsun. £150 for 4 worth a punt (205/60/14).

NS 20. That's a good deal. You'll like them.

Carolyn · March 21, 2016, 17:54

A little experiment. Disconnect the hose from the PCV valve. Start the engine. See how crap it runs. Has quite a large effect.

jonbill · March 21, 2016, 18:15

I tried disconnecting it with the engine running, and it dies very quickly. haven't tried starting it without the hose attached - I'd expect it wouldn't start....

jonbill · April 3, 2016, 15:15

Quick update: Neither a new PCV valve nor a couple of litres of Marvel Mystery Oil have stopped it smoking s:(

s:( .
So... Rebuild it is.
I took a 1hr subscription to toyota-tech.eu this morning and had a look around, and it seems that all the necessary details are there.
All I need is the space in the garage then....
The zed should be out for japfest on 24th, so the mr2 finished by end of June?

jonbill · May 30, 2016, 18:19

hi everyone -
I've started work on removing the engine. I've taken the bumper & exhaust off, removed most of the gubbins around the engine, drained all fluids & disconnected the loom from the engine.
The cross member is very solid which is good news (in fact, it's all solid underneath).
I'm now contemplating getting the driveshafts out of the gearbox - can I just pop the driveshafts out without undoing any suspension, or isn't there enough clearance for that?

Thanks.

Carolyn · May 30, 2016, 18:43

Hi Jon, Great to see you're getting started. My method is to disconnect the uprights and front links from the hubs and drop the engine and gearbox with the crossmember. You'll need some sort of dolley to drop it onto. But then, I've got a lift, which makes it all a bit easier.

jonbill · May 31, 2016, 07:32

Thanks Carolyn. That's what I'll do too then. I'm thinking I'll drop the engine on a rug, lift the car with the engine crane and roll the car forward. I think the crane has enough reach. We'll see!

jonbill · June 4, 2016, 19:02

Yay! Engine out

Carolyn · June 4, 2016, 19:24

Now for the fun stuff. I'd go for the eight-hole pistons from MAG.

jonbill · June 5, 2016, 10:02

Yep - got that kit in my watch list on ebay. I'm going to strip it down and measure the bores before ordering, just in case.... It was very smokey!

Carolyn · June 5, 2016, 10:37

Indeed that is a good plan. Given the compression readings, I'll be surprised if the bores are far off. My vote (which is not of any great importance) is for valve seals as you surmised.
I'm getting ready to do the pistons on the one in my silver car. Got a rebuilt spare engine but I've got uses for that one and the one in the car has a lot of new gear- just using a bit of oil.
Keep me posted on what you find. Also, if you need the loan of any tools, just ask.

jonbill · June 10, 2016, 18:25

I got the pistons out today - perhaps not surprising the oil control rings were well and truly stuck down. You can see a lot of cack in the ring groove that was sticking it down.

As per the other current thread, the bores and bearings are in great shape with the honing marks still clear.

So I may just give it a set of rings and big end bearings and put it back together.
I'll have to see how the prices come out in comparison with that MAG £300 piston & rebuild kit.

Carolyn · June 10, 2016, 18:51

You can buy just the Mag pistons with rings.
m http://www.ebay.co.uk/itm/PISTON-RING-S ... SwFNZWzbQX m

If you're going to keep the old pistons, we can modify the oil holes on the mill here. I would, at least do that.

I'd still do the valve seals. You'll need a gasket set with new bolts...
m http://www.ebay.co.uk/itm/310790776292? ... EBIDX%3AIT m

Generally speaking, stuck oil rings don't smoke - you do go though oil like crazy, but the smoke may well be your stem seals. Been through it - honest.

spit · June 10, 2016, 19:35

Another one who's been there. Valve stem seals all the way.

C'lyn: are these generic bolt and seal kits any good? I'd be inclined to go for Toyota's own overhaul kit - its not cheap (and excludes bolts) but its not horribly expensive either.
I'd worry about the quality and longevity of all that lot coming in at £55.

Carolyn · June 10, 2016, 19:52

I've used two.

No problems so far. I do think some Toyota 'originals' are over-rated sometimes and definitely over-priced.. They buy these things in after all. They don't make bolts and they don't make gaskets. They do mark them up.
I've generally done well with pattern parts.
Look at how much stuff the Ebay supplier sells and 99.8% positive feedback.
In the end the choice is down to the individual.
The care taken in the rebuild is the important bit for me.

jonbill · June 10, 2016, 20:21

Thanks both - yes, I'll deffo be replacing the valve stem seals as a matter of course.
That bolt & gasket set are a bargain! I'll grab one of them!
Looking at the rings MAG have for sale, it seems 1st & 2nd rings are the same - is that right? I was sure 2nd was thicker when I was taking them apart. I'll have to go measure.

Re modifying the old pistons - sounds a good idea. Are you busy this weekend? :-) :-) :-)

Carolyn · June 10, 2016, 20:32

1st and 2nd are different.
I'll have a word with David (royal high monarch of the machines).
I had an unused set of four-holed original pistons which are ringed up and modified... (ten holes!!!) but I've got uses for them.
I reckon doing an overlap on the existing holes and adding an extra on each side should do the trick.
We'll be home... just got to talk the old fart into doing it... you might want to consider some sort of bribery...
Give me a buzz in the morning.

jonbill · June 10, 2016, 20:46

Great, thanks. Will call in the AM.

Carolyn · June 11, 2016, 05:26

Quote from: "spit"Another one who's been there. Valve stem seals all the way.

C'lyn: are these generic bolt and seal kits any good? I'd be inclined to go for Toyota's own overhaul kit - its not cheap (and excludes bolts) but its not horribly expensive either.
I'd worry about the quality and longevity of all that lot coming in at £55.

There are some parts that do need to come from Toyota, though. For instance, the crush rings between the cat and manifold, the VVTI hub and various other precision mechanical bits.

jonbill · June 19, 2016, 10:27

Evidence of oil burning! Some of the valves have a couple of mm of carbon it seems

jonbill · June 30, 2016, 21:40

Bottom end re-assembled with new main & rod bearings, rings, seals and Carolyn modified pistons :thumbs

beavisrules · July 1, 2016, 22:02

Another thread hijack?. sorry.
I'm seeing different descriptions of head gaskets.
Carbon , carbon steel and multi layered steel.
All at budget prices so are they same thing with different sales spiel.?