What year 8?

Hi Geoff,

It is a 51. The numbers match so it is the original engine. It has been completely rebuilt and has only 15000 miles on it since the rebuild.

I would first of all check that the breather pipe in the tappet cover is clear. I have seen these cut with gaskets that cover the entire area apart from one hole big enough for the bolt to go through. The gasket must have extra holes to allow the chamber to breathe. The idea is that as the car moves, the passage of air past the bottom of the breather tube creates a slight vacuum in the engine, thus preventing pressure building up. If this is clear, then you obviously have problem with crankcase pressure, and this could be from various causes - worn valve guides, worn rings, or perhaps a ring-locating pin popped out allowing compression directly into the crankcase past the back of the rings. It is not possible for oil to splash up out the filler hole. Another long shot - I have seen the sump gaskets cut too wide, and partly covering the return slot in the middle right of the trough assembly, and the oil level rising too high in the toughs. Unfortunately in Step-down 8's it is not a simple job to remove the sump. You should trade it for a 1930 -'39 model! Good luck,
Geoff

Thanks for the advice Geoff. I had new valve guides put in it. It don't smoke any at all. I'm going to check on that vent tube gasket and hope that is the problem. If it is the gasket on the oil pan tray then I am going to have a Hudson for sale.

I forgot to tell you also that the new pistons don't have a ring locating pin like the original ones do. I hope a ring hasn't turned and allowing compression to go past the end gap of the ring.

How many miles has the engine done since rebuilding? It may just need time for the rings to bed in. If the sump gasket is leaking it's not the end of the world, you can just undo the bolts half an inch, prise the trays apart clean the edges thoroughly and put a smear of good silicone gasket around between the surfaces and re-tighten.

Hi Geoff,
I have put 15000 miles on this engine since the rebuild. Not sure I understand what you are saying about the sump gasket. Can you explain that a little more.

Hi again Geoff,

Ithink you have talked to my brother in law about his 53 Jet and have given him advice too. He still runs his jet but the pistons are slapping like crazy in it, I think.
I know what you are talking about as far as the return oil slot in the oil try. Are you talking about the oil pan gasket covering over that and not allowing the oil to get to the slot. It has been a while since I rebuilt this engine so I can't remember just what things were made like in that area but I'm hoping that the gasket on the valve covers is blocking the vent hole for the vent tube. I remember there was a lot of gasket there and a pan that went inside each valve cover with two square slots in each one. I figured this extra pan was to prevent oil from going out the vent tube by allowing to much oil to spash against the outer valve cover. I think the gaskets only had two square holes cut in them also instead of just an outer edge on the gasket to just seal the outer edge of the valve pans. Hope that makes sense but let me know what you think. Thanks.

My comments about the sump gasket were to cover the possibility of oil leaking out the joint, in which case you don't necessarily have to remove the sump completely, just drop it down slightly and seal with silicone. However, if the oil return slot is partially covered, the only way you can check this is to remove the sump. Not sure if the Step-down 8's have the gauze drain hole in the centre of the trough assembly, If this gauze was blocked, and the slot covered it could lead to higher than normal oil level in the troughs at the centre. Try the side plates first, and ensure that the gasket for the breather tube part is just a ring sealing around the round part, and allows complete venting to the interior.
Regarding the rattling Jet, you can use pistons from the 8's and 6's from '34-'37 for the Jet. I have them in my Jet and they work fine. A little heavier than original ones, but no noticeable difference in performance.
Geoff

When Geoff refers to the "sump" he means the oil pan. They talk funny down under. :woohoo:

Hudsonly,
Alex Burr
Memphis, TN

Thanks for that information Alex. I thought he was from New Zealand.

He is - just easier to type "down under". LOL

Hudsonly,
Alex B

Ha Ha. Gotcha Alex. 🙂

Hey Geoff,

I checked the gasket that you were talking about on the side valve cover pans and sure enough it was what you said it was. The gasket was blocking the vent tube. I cut the hole out to the size of the vent tube and it took care of the oil leak. Thanks for your good advice. Glad there are people out there in this club that are willing to give good advice. This car runs better than ever now and I'm not sure but seems to be doing better on gasoline. Thanks a lot. 🙂