Why oil weeps when using a 3v front cover with a non 3v block

[BruceH]

I'm cleaning parts today and decided to mock up a 3v front cover with an explorer block. This same condition occurred with the 1L Mach 1 block that is currently in my car. I plugged the extra hole but that wasn't enough. A mismatch between the block and gasket also happens.

Adding metal to the block and machining it flat would be the best solution but it's not very practical at the moment. I may try an oring and rtv around the bolt hole. The motor is coming out in a few days and this problem will get some attention. I'll post up if I figure anything out.

The mismatches are circled:

 

[YoungPony]

Filling that hole in the first picture would fix the oil leak there, correct? What would be the fix for the other two pictures?

 

[8306gt]

Before installing my Boss 5.0 iron block, I used JB weld to build up the offending area and so far in 3000 miles it hasn't leaked a drop of oil.

 

[BruceH]

Filling that hole in the first picture would fix the oil leak there, correct? What would be the fix for the other two pictures?

That's the reason I posted. I filled the hole in my current motor and thought I had it fixed but over time more oil made it's way down. It's not enough to even register on the dipstick between oil changes but it bothers me.

The other place is in the same area as the hole. It's where the front cover rubber gasket doesn't make contact with the block to seal it completely. The picture doesn't really show it very well. I know I'm not the only one who has chased this. I get about one drop of oil every 4 times it's pulled into the garage. It's not much but it bugs me enough to pull the motor and go over everything with a fine tooth comb.

 

[YoungPony]

That's the reason I posted. I filled the hole in my current motor and thought I had it fixed but over time more oil made it's way down. It's not enough to even register on the dipstick between oil changes but it bothers me.

Just confirming that was the fix since you said that it's not practical at this time. Is that just because the engine is still in the car?

 

[BruceH]

Just confirming that was the fix since you said that it's not practically at this time. Is that just because the engine is still in the car?

It is at the moment. I comes out some time next week. Even then it just won't be practical. There is a guy in town who has welded cast aluminum for me before but even if he added material on the block it would still have to me machined, that's where it becomes impractical for me.

 

[AbdullaGT500]

Mine didn't leak at all until I swapped the timing cover a month later. Now it has a few drops under it everyday.

 

[travelers]

You can tap the hole and install a allen pipe plug with a thread sealent.

 

[Bobby]

i am having the same problem with my boss block still i am going to fix it in the next week or so with a new seal and some rtv.

 

[BruceH]

Just a follow up to this thread. I also added an oring and rtv around the mismatched area. This was back in late May 2012. No oil leakage or drips since. And fwiw the leak was a two parter. The other part was the rear main seal. Do yourself a favor and buy a Motorcraft rear seal. The National brand I had was weeping a small amount of oil. An internet search turned up others with the same issue when using a National rear seal.

 

[AutoXRacer]

Why are you using a 3V front cover with a different engine?

Why not just get the right part for the right motor...? Just wondering.

 

[BruceH]

Why are you using a 3V front cover with a different engine?

Why not just get the right part for the right motor...? Just wondering.

A 3v cover is the only one that will work with 3v heads. Plus all the bosses are in the right place.

It is the right part for the motor. Anything else would not work.

 

[AutoXRacer]

Is the Explorer block different that the Mustang block?

Why didn't you reused your Mustang block? So you are running an Explorer block?
What are the advantages?

 

[BruceH]

Is the Explorer block different that the Mustang block?

Why didn't you reused your Mustang block? So you are running an Explorer block?
What are the advantages?

I have a 1L Mach 1 block in my car right now. I've had three motors over the years. Stock, 9.4:1 with a Whipple, and this motor. At the time I originally posted this I also had a 3L2E Explorer block in my garage, it's since gone to a good home.

The only advantage is price and availability.

The purpose of this thread is to help anyone who isn't using a 3L1E block for their build. I chased it for quite awhile until a solution was solved. If I can pass that info along then maybe someone else won't have to chase an oil drip.

 

[01yellerCobra]

Do you have the same issues with the iron blocks?

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[BruceH]

Do you have the same issues with the iron blocks?

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The big bore does. Don't know about the other ones. The Explorer uses a 3v head with an iron block so chances are some do, some don't but it's a guess.

 

[BruceH]

Just pulled the front cover. Here's a pic of what the sealant covered. Once I did this it didn't weep from the front again.

 

[Noclutch]

good. Think it is a perm fix?

 

[BruceH]

good. Think it is a perm fix?

Yes. It worked for over a year. The motor went from leaving a drop of oil every 4 times I pulled it into the garage to none. This was only part of my problem though. I had used a National brand rear main seal in the build. It came with a gasket kit. It was part of the problem too. It was also a good reason to put ported heads on. I couldn't see pulling the motor just to replace the rear seal with a Motorcraft one so I went ahead and installed FRPP cnc heads at the same time.

 

[michael.konor]

While we're on the subject of using parts that were not a part of the actual 3V setup, when installing the iron tensioners what is everying using to seal them to the block?

The stock plastic 3V tensioners have a built in gasket, while the iron tensioners don't.

So, is there even a seal needed or is it a situation where it sits so flush with the block that you don't need one since the pistons are "locked" in their farthest extension?