Optical illusion

Post by **Dirky52** » Mon Jan 14, 2008 1:34 am

Some while ago a member called "Speedbox" complained that the 'spin-on oil filter conversion didn't fit.

I was recently moved to replace the bolt through oil filter with the spin-on conversion. Not because it was easier to change but because it can be less messy and will reseal every time.

However on removing the bolt through one, cleaning the block face and replacing the studs. I notice that the orifice is similar to that of the one that ‘Speedbox’ describes. Just my luck I thought. I fitted the conversion and bingo a huge leak.

I contacted the supplier and I was told "you have one of the early blocks" to. I contacted another and was told "it must be a much later block."

I finally track down a conversion supplier that guarantees that the flange will seal the hole despite looking like it will not. 'Speedbox' originally described the hole that was visible above the flange on the conversion perfectly, in that he could put a screwdriver down it. I tried, and guess what...I couldn't. It was solid and not a hole after all. The words “despite looking like it will not” kept ringing in my ears. The supplier also said “are you sure you are seeing what you think you are seeing?”

I looked at the shape of the hole in the removed bolt through version and the shape in the flange was as I was looking at on the side of the block. What I was looking at was an illusion and part of the old gasket. The gradation in tone of the oil stain gave the impression of an elongated hole the same shape as on the oil filter flange, going from black as pitch to a lighter shade as it reached the edge. I could have sworn it was there.

It was hard work scraping off the remains of the old gasket taking a full hour. I cleaned the area with thinners making sure none entered the block. This was the only way I could tell if all the bits of gasket were removed.

The hole in the block was actually very small compared with the shape on the old filter…phew! New spin-on filter fitted and sealed perfectly.

Had the engine been out I would have seen this immediately. However, I have a brake servo on the engine mounting bracket and the view isn’t that great being at an angle.

My tip is to never assume anything and don't trust your eyes over the need to thoroughly remove all traces of old oil and gasket.

Post by **Peetee** » Mon Jan 14, 2008 9:59 am

I had trouble fitting the spin on kit too but, as far as I can ascertain from the descriptions given so far, my problem was different.
The OE filter mount on the engine appeared, externally, to be standard but the alloy adapter collar wouldn't thread up to meet the mount. Inside the mount was a fixed, dished plate that was getting in the way. I Mailed the trader who sold me the kit for advice enclosing a photo (since lost

) to see if the dished plate needed removing (there was no explaination in the instructions). The trader (well established I might add) said he had never seen anything like it on a A-series engine.
The kit was never used.

Post by **Dirky52** » Mon Jan 21, 2008 12:43 am

Peetee wrote:I had trouble fitting the spin on kit too but, as far as I can ascertain from the descriptions given so far, my problem was different.
The OE filter mount on the engine appeared, externally, to be standard but the alloy adapter collar wouldn't thread up to meet the mount. Inside the mount was a fixed, dished plate that was getting in the way. I Mailed the trader who sold me the kit for advice enclosing a photo (since lost ) to see if the dished plate needed removing (there was no explaination in the instructions). The trader (well established I might add) said he had never seen anything like it on a A-series engine.
The kit was never used.

From your description you have the adapter that will fit under the original filter housing and converts it to a spin-on type. I have no knowledge of this type of fitting. The thing that worries me about this type of filter conversion is that it has two seals i.e. one for the adapter and one for the spin-on filter. I take it that there is a replacement bolt for the adapter to connect to the old filter housing and some form of 'O' ring between it and the adapter. Then its a case of screwing on the spin-on filter. Mmmmm...interesting. I think by not fitting it you did the right thing. I can't think how you can prevent leakage with such an arangement. Life's hard enough on the old girl as it is.