fbekholden.com

Compeleted the re work of the block and head for the new improved head gasket. For anyone about to do this makes sure you use sufficient dowels or head bolts to set the head gasket in place. Once thats done and the gasket is in its best possible position, ensuring even alignment over all holes, go and mark the areas over the back two coolant passages.You will see the new gasket is a really good fit on the block, but the head is another issue. I think this would be due to casting inaccuracies. What all this means is that I had to use a die grinder to enlarge the holes in the head due to a slight offset needed at both holes. The block was fine with no offset needed for either hole. I also found it was better using the die grinder and a vacuum rather than a drill that would cause larger casting chips and would tend to chunk out the casting inside the block. Also didn't out of preference go to the max on sizing out the larger of the two holes due to its proximity to the combustion chamber seal. There's not much meat there between the coolant passage and chamber which could be a path for cumbustion leakage and pressurisation issues.

Engine back in and running tonight. Idle quality is much improved now. Engine now idles smoothly at factory 2 degrees initial timing.
Ran engine for 20 minutes or so and left the flywheel cover off so I could check the rear main. Fingers crossed so far, no leakage.
More work tomorrow.

55 km's now done and not one drip from the rear main.........touch wood, touch wood, touch wood, touch wood, touch wood, touch wood, touch wood, touch wood, touch wood, touch wood, touch wood, touch wood, touch wood, touch wood.

Am really impressed with how much cooler it runs with the new head gasket. I will be now either running without the fan or going for a higher temp thermostat. Temperatures across the head right back to the rear of the block are nice and even. 71 degrees front to back. Spot on thermostat opening temp. Happy days so far. Just some tweaking with the advance curve now and a final crankcase pressure test. Breather pipe is also drip free so far. Touch wood again!

Could this be finally it???

Good news about the cooling mods. You will have to fit a warmer thermostat Craig. The fan stops overheating in traffic on hot days but has virtually no effect at speed which I'm sure you're aware of.
Fingers crossed on the rear seal.


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Thanks Errol. I used to be of that thinking with the fan but after last summer and towing on the highway the fan made a big difference.

Craig Allardyce wrote: ↑Sun Jul 16, 2017 4:49 pm Am really impressed with how much cooler it runs with the new head gasket. I will be now either running without the fan or going for a higher temp thermostat. Temperatures across the head right back to the rear of the block are nice and even. 71 degrees front to back. Spot on thermostat opening temp. Happy days so far.

Really good news on the cooling . This must be one of the few early Holdens where the original cooling system is sufficient for the thermostat to properly cycle. Most get warm, open the thermostat and then it stays wide open as the cooling system is not sufficient (radiator sludge, fouled cooling jackets, worn water pump etc).

Cheers,
Harv

Harv wrote: ↑Mon Jul 17, 2017 8:22 am

Craig Allardyce wrote: ↑Sun Jul 16, 2017 4:49 pm Am really impressed with how much cooler it runs with the new head gasket. I will be now either running without the fan or going for a higher temp thermostat. Temperatures across the head right back to the rear of the block are nice and even. 71 degrees front to back. Spot on thermostat opening temp. Happy days so far.

Really good news on the cooling . This must be one of the few early Holdens where the original cooling system is sufficient for the thermostat to properly cycle. Most get warm, open the thermostat and then it stays wide open as the cooling system is not sufficient (radiator sludge, fouled cooling jackets, worn water pump etc).

Cheers,
Harv

It's been really cold down here (some days we have been colder than Mt Hotham and we've got down to -7). I dont know how anything cycles at all in this weather lol. I love my Warmaride.

Happy days again. I think case closed on this problem.
Final crankcase pressure test with engine fan removed and engine up to temp 85 degrees, flat biscuit at 80mph and pressure was no higher than 1.1" H20. My previous was 1.6 - 2.2" H20 flat throttle accelerating through to 60mph and 3.2 at 75 mph. Cruising and acceleration through 60 to 70mph now down to 0.4" H20. Its a dramatic change for just doing valve guides. And by the way, I'm back to standard side plate and breather arrangements. Still touching wood though! I hope the next problem isn't as difficult as this one turned out to be. Wondering if I should name and shame the mob that supposedly overhauled the head.

Craig,

I have watched this with interest and to be honest quite surprised that this was the problem.
In essence because of the sloppy valve guide measurement, being way larger than it should be the engines gasses are in fact bypassing the guides and pumping up the crank case ! This would probably be blamed on ring wear with a high millage engine and would never be checked because most people just reco the whole lot at once.
I bet many a good mechanic would be scratching their with this issue ! Anyway good find, although its disappointing to buy something that's not up to scratch !

regards Greg

Thanks Greg. Dont worry it had this mechanic scratching his head for while. Tassie Nats gave it away. Coming off Mt Wellington in a cloud of blue smoke said it all. Once under full throttle it cleared up. Dead give away for valve guides. The compression test after that confirmed it. All good at about 150psi

Test run to Dargo yesterday, 20 degrees, some wind, hillclimbing and windy for about half of the 200 km trip, and no fan on the engine. Temp averaged around the 75-80 mark for all of the trip. Wouldn't like to push it with no fan when towing the camper or boat. Found a small oil leak at the breather tube where it fits into the side plate (thought it was the fuel pump) and the rear main is still good. At the end of the day the rear main leaves a small drop of oil smaller in size than a one cent piece. I think that is acceptable!
Breather pipe leakage has stopped so far but I'm going to plan a long run with the boat or trailer on where I can do some decent highway speed up a long grade. Just got to find a place around here.
Have come across a problem with my ignition module as I've noticed a drop in idle quality. Seems the dwell at idle gets down to 10 degrees and is plotted similar to an advance curve (increases with RPM). They do this to reduce coil temperatures at low RPM's. Problem is it's not enough dwell for this old bus to run smooth and to pull away cleanly with a load on at idle or low RPM's. Swapping back to either the Pertronix or the standard distributor fixes the problem but then I'm back to the advance rate not being suitable for this engine with the shaved head and increased bore. Have been trying with the manufacturer to get a fix for the problem but thats been difficult being that they are in the USA.
https://www.youtube.com/watch?v=YjGOmkZ ... e=youtu.be
https://www.youtube.com/watch?v=rXhCcHP ... e=youtu.be

Craig,

I've just read the last couple of pages of this thread with great interest. You're the first, as far as I know, to have installed a 7424869, and I'm glad to see that it went well.
Commiserations on the spun rear-main-oil-seal problem. Been there, done that . . . (bloody frustrating too)
When I "faked" the 7424869 head gasket with a standard one and sheet Teflon blanks, I found that the holes behind number 6 cylinder in both head and block were spot-on concentric with the holes in the head gasket, once the gasket was aligned correctly. I had no problem drilling the holes out in the head; but in enlarging the hole in the block, the 5/8" drill grabbed right towards the end and I finished the hole with a round file.
Is your rear main oil seal setting tool an original 6A7 (if that's the right number?) Does it make the job any easier?

Rob

Hi Rob, yep its the original tool. I just unscrew the handle out of it so I can clamp it in place when setting the seal.

Craig,

Could I ask a favour, then -
What are the diameters of the tool (both the bearing tunnel section and the seal-setting section)?
It'd be easier to reverse-engineer the tool than try to scrounge one up.

Thanks,

Rob

If you want exact dimensions you'll have to wait till I get back from work next week (Wed).
If someone can get you the main tunnel size I know that the seal area on the tool is .002" smaller in diameter.

ardiesse wrote: ↑Mon Jul 31, 2017 4:25 pm Craig,

Could I ask a favour, then -
What are the diameters of the tool (both the bearing tunnel section and the seal-setting section)?
It'd be easier to reverse-engineer the tool than try to scrounge one up.

Thanks,

Rob

I think I've got a spare one if you want one Rob (don't ask how I ended up with two )?

Cheers,
Harv