Crown engine rebuild specifications

[1975ToyotaCrown]

I have a Toyota Crown engine that was fully rebuilt 10 years ago but never started, I now have pulled it down to replace the rings and give it a complete new set of gaskets.
On top of the new pistons are the numbers RA2686 0.50 Top 0.04 GE 2
what does the 0.50 mean is that 50 thou over the standard size.

If I was to just supply this info could I get the required rings.

[ra_28]

It's 0.50 mm over standard size. Getting rings would be easy just take down your piston and rings.

Cheers
Alex

[1975ToyotaCrown]

I'm not sure how to get the pistons out, do I need to remove one at a time or can I just undo the crankshaft and remove them all in one go still connected to the crankshaft, can I then reinstall them still connected to the crankshaft..

[cambelt]

Dont touch them at all , they will most likely be repco hardchrome rings that you cant buy any more . the headgsket will be a old aspestos type , again that you cant buy . the only things you would replace are the seals. You will creat more damage by replacing parts with parts that are of avg quality known to a 4 or 5m
Dave

[thechuckster]

too late - he said he'd pulled the motor down.

to remove the pistons, you undo the big-end caps then push the pistons out the top of the bore. You'll need a ring compressor to refit the pistons back in.

[1975ToyotaCrown]

I still have the pistons in there holes and still connected to the crankshaft, the head gasket is a cooper looking material which still looks ok. I was told because the engine had sat so long the rings will need replacing, I would prefer not to replace them but then again I now have the engine apart so whats the harm, if I was to remove one piston and take the rings to an engine rebuilder could they tell me if they need replacing.

[ra_28]

Head gasket is only good for a sample to get a new one made if you can't find a off the shelf one to buy, never reuse a head gasket it will only lead to problems. Take your sump off and and do what thechuckster said.

I would be very suprised by looking at those bores if the rings were dead.

Cheers
Alex

[gianttomato]

Don't touch that motor.

Buy a head gasket and put the head back on.

Just replace the front and rear main seals.

[1975ToyotaCrown]

All pulled apart both the front and back covers and sump cover, I pushed out a piston this morning and have been told they are still in perfect condition so when the complete gasket kit arrives on Wednesday I'll refit the new seals and get it ready for a coat of red the put it back together. I refitted the piston and rings with a piston ring installer from work this morning, I'm on 10 days toil leave..

[1975ToyotaCrown]

Can the pulley part on the 4mu Crown harmonic balancer be removed. I can't see how but then again there may be a way. The harmonic balancer on the 4m engine out of the 1975 Crown is near new but only has room for 2 belts where as the pulley from our 4mu engine has room for 3 belts so can the 3 belt pulley be put onto the 2 pulley harmonic balancer.

[gianttomato]

Remove 2 pulley harmonic balancer and fit 3 pulley balancer. Before you fit it up, line up the keyways and make sure the timing marks line up.

["Z" UTE]

I still have the pistons in there holes and still connected to the crankshaft, the head gasket is a cooper looking material which still looks ok. I was told because the engine had sat so long the rings will need replacing, I would prefer not to replace them but then again I now have the engine apart so whats the harm, if I was to remove one piston and take the rings to an engine rebuilder could they tell me if they need replacing.

Whoever told you that the rings should be replaced has no idea. Piston rings will only deteriorate with wear and heat. Sure the bore should have been checked to ensure there was no corrosion having sat for so long. That being said, if the intake and exhaust had been properly covered to prevent breathing then the bores would have been fine. Other than that, replacing all the rubber seals will be the safest way to go, because they will all have age hardened.

You should get many years of happy motoring from this engine when put back together.

cheers Chuck.

[cambelt]

Oh get the valve stem seals replaced as well . I still have a brand new from toyota 4M bottem end , also a brand new 5 m block and piston kit .
Dave

[1975ToyotaCrown]

Theses no corrosion in the bores as I removed all the pistons today to check but some of the bores had some hard engine assembly goo stuck around at the top of the pistions. I used thiners to some steel wool to gently remove all this. I also degreased all the bits in the bottom end around the crankshaft as it had big chunks of hardened oil in there, I unassembled using assembly lube and torqued everything back to the tensions in my Crown repair manual.
I have a complete ACL engine gasket kit coming for the engine on Wednesday so this kit should have these seals and the valve stem seals right. I'll take the head over to our one and only local engine re conditioner when the gasket kit arrives or maybe using a valve spring compressor could I replace the seals myself.

[1975ToyotaCrown]

And as for the harmonic balancer the 4m 2 belt pulley has only done 80,000 klms but the 4m 3 pulley one has done 330,000 klms but then again after looking closely at the harmonic balancers I see no rubber bits like a Holden one, the Crown ones are all steel so maybe the 3 pulley one would be alright as it still runs straight.