Improved rubber parts

[Declan_Burns]

Thanks Phil.
Good tip on the Marina parts.

Simmitc,
Pretty soon I would think. Certainly this side of Christmas.

Regards
Declan

[danielvoorwerk]

Great, i would surely buy/need them by then ;-)

[Declan_Burns]

We made the final adjustments to the mould yesterday and produced the first batch of trunnion seals.
We are quite pleased with the results.

Regards
Declan


To sum up how this is actually done:

Injection moulding machine-mould female part[frame][/frame]
Injection moulding machine-mould male part after mould separated[frame][/frame]
First batch of trunnion dust caps and sealing rings[frame][/frame]
Close up with thrust washer fitted[frame][/frame]
Different angle[frame][/frame]
Final seals[frame][/frame]

[M25VAN]

Looking good.

[biomed32uk]

I am certainly up for testing some tappet chest seals, about to rebuild my engine after its recent troubles.

Looking good all your efforts.

[Declan_Burns]

Biomed,
I am afraid I have no samples of the cover seals here left at the moment. What we have learned through the assistance we got from this forum who has kindly test fitted them is that for the seals for the concave covers, we will have to increase the thickness as the ridge where the seal sits can vary in depth from 3.5 to 4.5mm. The convex seems to be fine. Maybe my mate has a few test sample lying around-I will ask him tomorrow.
Do you have the convex or the concave covers?

Regards
Declan

[bmcecosse]

I notice some of the covers (with sprue still attached) seem to be split Declan?

[Declan_Burns]

Well spotted Roy,
That's to show the wall thickness. I dissected some of them as part of destructive testing!
You can see it better on this pic.

Regards
Declan[frame][/frame]

[bmcecosse]

I did wonder - so not tearing as they are ejected from the mould. It's a great project - although I do wonder at the commercial viability.

[danielvoorwerk]

Well, you can put me on the list for a set rubbers for the trunnions !

[Declan_Burns]

I did wonder - so not tearing as they are ejected from the mould. It's a great project - although I do wonder at the commercial viability.

Roy,
Being semi retired since the beginning of the month it's more the challenge and the occupational therapy than anything else.

Regards
Declan

[bmcecosse]

Ahh -well - that's a different story then !

[rotgnom]

[Declan_Burns]

Here's the progress on the trunnion seals for the early minor (Pre July 1952)
Moulded today-still some fine tuning required but getting there.

Regards
Declan
[frame][/frame]

Close-up[frame][/frame]

[biomed32uk]

A bit later than planned, and I am sure you have it sorted out by now, but I at last have my engine block back from the machine shop so will be building it back up over the coming days and can test those new side cover seals out you kindly sent me.

[rreems]

Hi Declan

Just heard some good reports about your trunnion seals for Morris Minor. Where can I purchase a set from please?

Kind regards

Richard

[Fingolfin]

Declan, if you're looking for ideas for rubber parts to make in future, may I suggest engine mounts? It seems like the repro ones are very hit-or-miss - often they're too hard and transmit engine vibration into the car.

[jagnut66]

Hi,
I agree with 'Fingolfin' on the engine mounts, I have just reused my originals, rather than waste money on the current crop of replacements.
Best wishes,
Mike.

[irtubes]

Interesting discussion here. One aspect often overlooked in “improved” rubber parts is not just the mould or design, but the formulation of the rubber compound itself.

Many modern rubber components tend to degrade faster because of changes in additive packages, particularly the reduction or substitution of certain processing aids, antioxidants, and reinforcing additives that were commonly used decades ago. Improvements today often come from optimizing the chemical additives used during compounding—such as specialty rubber chemicals, anti-degradants, and dispersion aids—which directly influence aging resistance, flexibility retention, and overall durability.

In restoration and performance applications, selecting rubber parts made with enhanced additive systems can make a noticeable difference in longevity compared to standard aftermarket replacements.

We work closely with manufacturers supplying such specialty additives for rubber and polymer applications at I R Tubes Pvt Ltd, and it’s interesting to see how much of the performance improvement comes from the chemistry behind the part rather than just the design.

[Bill_qaz]

Probably changes in the 11years since the topic was first posted.