Pulled out my engine today

[RaceDiagnostics]

I painted the solenoid and starter motor today.

Then on to fix this rusted and sheared off bolt.

I drilled it out before getting the manifold cleaned but managed to damage the thread.

So drilled it out and taped it for a helicoil.

Installed with thread lock a bit below the surface so as to be fitted in good threads.

 

[RichardM]

On the subject of oven cleaner, it's usually caustic soda, drop the parts into a bucket filled with water and a couple of ccs of vinegar to neutralise afterwards.

 

[Gareth_16V]

If you've changed the guides, you need the valve seats re-cut, not lapped in. There's likely too much material to do with lapping each valve in, unless you're very lucky, and you could easily wear the valve seating faces concave.

 

[RaceDiagnostics]

That may be the case, I'll find out on Friday when I get the dry ice delivered and get the guides fitted.

I want to do the minimum valve seat cutting as it results in the possibility of needing new shims which cost £25 each, x16 gets expensive.

 

[Gareth_16V]

Yes, that's the issue with 8x everything - I guess you're feeling lucky that it's not 4v/cyl! I feel your pain, I have just done the same (replace guides and recut seats) on a Ducati engine - 8 valves but 16 valve clearances to adjust - and so far they've all been wrong! The seats will be well out one the guides are replaced, but need proper measurement to show up - valve springs are strong enough to bend the valve enough to make them appear to seal properly, but of course with a big risk to reliability.

 

[RaceDiagnostics]

I stripped the paint and rust off the harmonic balancer and main pulley today....

....but spraying primer at 1 degC didn't work out too well. I will need to sand out the runs.

 

[RaceDiagnostics]

First sleet of the year overnight.

The delivery of dry ice turned up by 10.30. Somewhere below ~-80degC I presume, the digital thermometer only goes down to -50degC.

Head in hot water, heating to 80degC and a couple of heater strips to keep the head hot once on the bench.

Guides into chill.

Head up to temperature.

All the guides pushed in, all went in easily apart from two that took a bit more force.

Next, two expensive reamers, 8.99mm and 10.99mm.

They went through the cooled down guides fairly easily and only one seemed to cut a tiny amount.

Lubricated with wd40.

The next job will be to check the valve to seat seal.

 

[minimutly]

As @Gareth_16V said, you will need to have most seats recut, I've seen guides from Paul Ivey out of conc. by as much as 8 thou, and factory ones are no better. You better hope you can chop and change shims once cut and lapped. Hours of fun.

 

[RichardM]

Check your manual to see if you could also have the valve stems tipped if there is enough meat left above the collets.

 

[RaceDiagnostics]

I still have 13kg of dry ice slowly evaporating in the garage, I only needed 1kg or so but the minimum order was 15kg.

Today was spent lapping the valves. First engineers blue on the seats....

...and valves.

I used course then fine lapping compound using a conventional hand tool.

It was a slow pita but it showed all valves to be concentric with the seats, all valves showed a very consistent even pattern.

I then gave all the valves a second lap with the fine compound again. Using the hose to connect the drill takes out the risk of canting the valve stem.

Finally I did a leak test, each recess filled with water.

I ended up with a small single drip on about half the valves after 5 minutes. I have no idea if this is good enough or not, I guess with the valve springs fitted this would be much better.

Tomorrow the other head.

 

[Seadog]

Grinding the valves should be with a reciprocating motion, not rotary. Also guard against overgrinding which will result in concentric rings on the seat and valve.

 

[RaceDiagnostics]

Yes, the reverse switch has never been used so much on the drill.

 

[Cyberprog]

All very well doing a leak test, but you need to know the expected results to say if it's any good or not! I suspect like you though, that with the springs on it should be fine.

 

[RaceDiagnostics]

The workshop manual gives no advice or specs on this.

 

[Melvyn Best]

Looks like you maybe used too much engineers blue also water isn’t the best fluid to use when testing

 

[minimutly]

I still have 13kg of dry ice slowly evaporating in the garage, I only needed 1kg or so but the minimum order was 15kg.

Today was spent lapping the valves. First engineers blue on the seats....

...and valves.

I used course then fine lapping compound using a conventional hand tool.

It was a slow pita but it showed all valves to be concentric with the seats, all valves showed a very consistent even pattern.

I then gave all the valves a second lap with the fine compound again. Using the hose to connect the drill takes out the risk of canting the valve stem.

Finally I did a leak test, each recess filled with water.

I ended up with a small single drip on about half the valves after 5 minutes. I have no idea if this is good enough or not, I guess with the valve springs fitted this would be much better.

Tomorrow the other head.

Well you are a lucky so and so, well done!
Edit to add, I clean eveything up, bounce the valve up and let it drop on the seat - if it bounces once or twice the seat is concentric, if it falls with a slap, the seat is out. You can also "feel" it with a finger either end of the valve and lower it slowly.

 

[Seadog]

water isn’t the best fluid to use when testing

I think that petrol is often used. Less surface tension.

 

[minimutly]

If you need fluid, any fluid to test for a good seat you need help.

 

[Cobbler]

I think that petrol is often used. Less surface tension.

I’ve used paraffin

 

[OJCar]

I use petrol to test valves against their seats.
I would not expect to see any leakage at all.
The valves own weight should hold it shut.
Try cleaning the valve seat and valve head and test again with petrol.