Oil Gallery Screwed Plugs

[philthehill]

[irmscher]

Thanks Phil I found this very interesting and informative

[philthehill]

Happy to be of help.
Phil

[les]

Here we go again! Referring to photo below, there are 3 holes in this area, one is the oil return to the sump (larger of the 3) one is plugged with brass and is shown in the photo 7 (outer gallery) the 3rd, and unknown one, is 1 inch deep and blind. I can't tell if it's blind because it's been plugged or whether it's just a drilling that ends an inch down.
Either way what's it doing? The picture shows the cluster of 3. Ignore the main bearing cap threaded hole and the sump securing hole to the extreme left.

IMG_1224.JPG (1.78 MiB) Viewed 1708 times

[philthehill]

Les
Sump securing bolt hole.
Should have 1/4" UNF female threads.
I have just checked a spare 1275cc Marina sump and it matches those holes in the photo.
Phil

[les]

Sump securing hole! Well I never, what an embarrassing oversight! Too engrossed in oil galleries to see the obvious! Thanks Phil.

[les]

The thread I tapped in the oil galleries was UNF, I have managed to get some 5/16" unf grub screws for the small galleries but not for the larger galleries. I've had to settle for 9/16" unf bolts and cut them down to suit.
Unless anyone knows a supplier for 9/16" unf grub screws?

IMG_1226.JPG (839.11 KiB) Viewed 1663 times

[philthehill]

https://www.ebay.co.uk/itm/1-4-5-16-3-8 ... 4173738fe8

I used 5/8" UNF grub screws for the main oil galleries.

https://www.ebay.co.uk/itm/5-8-x-5-8-UN ... :rk:7:pf:0

I have used gwr -fasteners on many occasions and they are very good with quick service.

Phil

[les]

Yes, maybe I should have checked the availability before tapping, as 9/16" apparently isn't a preferred size. I must have gone for the the smallest tap required to achieve a good thread. Thanks for the link but the site doesn't show 9/16. I'll work on the bolts I have and slot one end of each plug. I don't really want to retap.

[ampwhu]

hello Phil, got my machined 1275 block back today. Following your advice, I had the oil gallery holes drilled and taped. I asked them what size they had taped to and they said 1/4" npt. Looking at them when I got home, they certainly weren't that!

I've measured them at 1/2" NPT and around 1/2" deep. I have purchased 4 plugs and they should be with us this week. Whilst I wait, I have filled the block (as much as I could) with citric acid and am leaving for a couple of days. Some pictures of the drillings:

Oil gallery plug1.JPG (70.73 KiB) Viewed 1186 times

oil gallery plug2.JPG (65.64 KiB) Viewed 1186 times

1275 blockj.JPG (81.32 KiB) Viewed 1186 times

the old core plugs have been put in to hold the acid in the waterways.

[ampwhu]

also Phil, could you tell me if the block I have is a 'thick or thin flange' block. Not that it matters to me...….

[philthehill]

You appear to have a thick flange 1275cc block.

Have you drilled out and either put back the original type knock in plugs or fitted screwed plugs to the other smaller galleries. They are just as important as the main fore and aft galleries.

[ampwhu]

erm….. I thought there were only 4? i'll look tomorrow. Does it matter that I've only had the horizontal 4 done?

[philthehill]

See my photo No: 7. posted on the 21st September 2015 on page one of this thread. It shows the other two gallery plugs. Note my comments.

[ampwhu]

the vertical plugs have been removed and new plugs inserted. machine shop has done that. in fairness, the oilways are very clean. I've put a rag through and a magnet and both came through clean.

not the same for the water ways...…

magnet particles.JPG (50.22 KiB) Viewed 1152 times

using a magnet, this is what i've started to pull out from the water jacket around the rear cylinder wall. That is bad. The front of the block isn't so bad. This is why i think these engines overheat from the rear cylinder. This citric acid has loosend this is 24 hours!

[philthehill]

Well done
That citric acid is good stuff for getting rid of the water jacket corrosion. I left a citric acid mixture in a 948cc block for a month and it came up like new. I have got another 948cc block to do and I will try and post some before and after photos in a new thread.
I have just soaked a rusty cast iron water pump impellor in a citric acid mixture and that came up like new.

[ampwhu]

Water pump has been submerged since this morning. Iron one as well. I'll leave it a while

[ampwhu]

embarrasing .

I received my 1/2" NPT plugs and they were too big. I emailed the seller and sent a picture of the plugs. his replay was.....

"google how to measure NPT threads"

well I didn't know this. so I have got 1/4" taped holes in the block afterall. they measure 1/2" wide and 1/2" deep but are definitely taped to 1/4" NPT. I ring my mate up and he rustles the pages of his "zeus book" and tells me that I am wrong and indeed the seller is right.

flaming hell, why not just use metric this day and age...……..

[pgp001]

With Pipe sizes they are measured by the nominal bore of the pipe, not the diameter of the thread.
A lot of folks make the same mistake I am afraid. I suppose its what you are used to dealing with, in my job I use these sort of fittings all the time so dont even think about it.

Phil

[oliver90owner]

flaming hell, why not just use metric this day and age...……..

Even using metric one would need to differentiate between pipes and tubes?

Pipes, tubes, parallel and tapered theads, olives or flared ends - they all have their place within engineering.

Metric would not help for items made in the stone age.