Oil leaks (BDA/BDR)

[Roger King]

Is the engine dry sump? If it is, the breather above the fuel pump is redundant and should be blanked. If you have a wet sump engine, opinions vary! Personally, I feel that the breather hose at the front of the block is perfectly sufficient, but some will argue the point. 

I have to say that I have built very few wet sump BDAs (or whichever suffix your particular variant is - I suspect BDR). The works rally engines were all dry sump (obviously) and were also aluminium blocked, so several things, including breathing and the oil system were laid out in a non-standard way. When I started to build BDR kits from Cosworth I had to get used to quite a lot of differences.

The most surprising was that Cosworth supplied what appeared to be unsuitable hose for the front oil drain. This rapidly hardens with heat and oil exposure and is almost guaranteed to leak after a while. Replace both this and the front breather with  softer, oil compatible hoses.

Don't dismiss the front camshaft oil seals, particularly since they are so close to the drain/breather hose. I posted earlier in this thread about them; in my experience, adding the oil drain holes makes a huge difference. Most will leak without the drain holes, but occasionally you might get lucky.

[jcerier]

Thanks so much - such a wealth of information here. My engine is dry-sumped. Any recommendation for how to block off the opening in the head and the block where that hose currently is? What parts to use, and how to install them?

[Tazio]

On mine they resemble coreplugs, what they are actually called I'm not sure.

[Roger King]

Firstly, I need to say that I came out of the competition engine world in 2003, so I may be a little out of touch. However, it used to be possible to buy blanking plugs for both the block and head. The plug in the block is exactly the same as would be used in a Crossflow block. I'm not sure about the size of the plug needed for the head simply because I have never built a BD(insert your preferred suffix here) that wasn't blanked off from new in the factory, but I wouldn't be surprised if it's the same as the block.

You can see the plug in the head here and it should be quite simple to get one turned up in aluminium so long as you can measure the diameter of the hole. Failing that, http://www.burtonpower.com will probably be able to help here in the UK. I would strongly recommend an interference fit of around .001" with a lead in about .002" smaller and the use of a Loctite retainer; centre punching the block and head around the plug will also help to keep it secure.

[jcerier]

I'm thinking that given the limited access I have (I wouldn't be able to swing a hammer within the space I have to work), plugs like this in the correct sizes might be a good option for me:

https://shop.advanceautoparts.com/p/dorman-autograde-rubber-expansion-plug-3-4-in-size-range-3-4-in-7-8-in-02608/89014938-P

Thoughts?

 

[Roger King]

I've never used anything like that so I can't really comment other than to say that the breather hole in the block is not very deep so these plugs may be too long and that I would be very keen to make sure that nothing could vibrate loose and let bits drop into the block or head.

Another way might be to turn up some plugs with a top hat shape that are a close slip fit into their locations. The "brim" section would stop them falling into the engine and they could be secured with one of the stronger Loctite retainers; I've not done this ever so be very sure that all is thoroughly degreased and secure.

[jcerier]

Good point re. the loose bits. I actually thought of a way to install the standard plugs. Either a rod with a sliding cylinder on it, to use as a slide hammer to press them both in, or alternately a threaded rod, nuts and fender washers, to press each cap in simultaneously, as the nuts are rotated to push both caps away from each other. That would result in the caps being pressed in perfectly flush. Lucky that both holes are on center with each other.

[Tazio]

You could contact some UK based BD engine builders, for the necessary bits, Wilcoxengines who did mine, or Sherwood engines, run by Alan Sherwood. I know Alan is on Facebook, ( search Alan Jeffrey Sherwood) so even though they maybe locked down it's one way of contacting him . Just a thought.

[ECR]

Freezing the plugs will aid easier insertion ......

[Philip L Anderson]

After my last BD rebuild I had a serious oil leak from one of the two hoses on the front left side of the engine. I tried several different metal hose clamps but without any luck. I then used Gates Power Grip Clamps and haven't had any problems for years. The Gates clamps are heat shrink tubes that supposedly get tighter with age. 

[jcerier]

Philip - thanks! I'll look into those clamps.

[jcerier]

What particular sealant would folks recommend to seal the plugs when I insert them?

[Roger King]

I would use one of the Loctite retainers, perhaps 641 if that is still current. This will both seal and retain the plug (if you are using a turned plug rather than a thin welch plug type item). I'd recommend the plug is aluminium, particularly for the head, so that you don't encounter any differential expansion problems. You need to thoroughly degrease all surfaces and it would be a good idea to roughen the joint surfaces up a little to allow the retainer to grip more efficiently. 

In reality, you should be fine with a plain aluminium plug and an interference fit, but belt and braces never hurt anyone.

[jcerier]

Makes sense, though my block is steel so I assume aluminium wouldn't be a good option on that side.

[Roger King]

Aluminium is fine for the block as well, but just keep the interference fit to a minimum. Steel would be just as good though. As per my previous post it would be a good idea to give them a top hat section with a small "brim" of just a few thou. to stop the plugs falling inside.

[TomB]

You need to fit one of these, a snip at £21grand+vat.  Im sure it wont leak at that price.  

http://www.wilcoxengines.co.uk/Engine%20For%20Sale%20on%20Site/On%20sale%20now%20new%20fia%202%20litre%20bdg%20page.htm

[Tazio]

When he rebuilt mine last year, he was building up a brand new BDR up for a guy in Malta, for his Mk1 Escort, a cool £16.5k.

One day i walked in and John and his wife Rita were dynoing a 2 litre BDG, it sat on the dyno, with Rita on the throttles, engine was howling at 9,200 rpm, she looked at John, and just said' That's a good one',and smiled .... 

 

[anthonym]

One day I hope my engine can go to John and Rita, but not yet.

Meanwhile I found this thread via google searching for what the two vertical hoses do and I see "

"One hose is a breather, the other is an oil drain tube." Which explains why one has oil under it and the other looks dry.

I have not yet found the exact specification for each hose and to remove them looks like a job full of opportunity for d.i.y. mistakes. I guess start by moving or even removing the alternator to provide some room. The suggestion of using those heat shrink seals/clamps looks like the ideal. Looks to me like to fit or remove the hose has to be bent in an awkward fashion, I suspect requiring some muscle, or not. Anyway, all this thought I decided to tighten the existing clamps, clean off the oil and see how we go for now. The hoses don't look to be in too bad a condition. 

Access to the top two clamps is easy with 1/4 drive and socket. The lower two are a very different story; so I jacked up the car and gained access with the following tools (1/4" drive with several wobble extensions and universal joint for the oil drain and straight edge screwdriver end for the breather, no universal joint.) Didn't take long, but very awkward - and for those who wear specs I had to use reading glasses instead of my usuals because of the close proximity. Or find a short sighted helper ;-) 

I dread the idea of replacing the cam seals.

So tools and part pics below (in next edit). A T B Anthony