Rear main cap install question

[4406bbl]

Thank you for the suggestion on talking to my machine shop. I will let you know the results of this option.

What you are measuring tells you nothing. Measure rear of seal groove to rear of block,then rear of seal groove to rear of cap. With a little math you can then determine exactly where the cap should be located. Then try the bolts before drilling anything, it may be correct.

 

[4406bbl]

For the non believers....pics of a 440 with an unfixable rear main leak, so they said. This engine has been sitting on its back for 2 weeks with oil sitting in the rear main. No leak. The fix was taking .010 off the retainer, moving the rear main bearing cap forward so the recess in the block and cap lines up, which let the seal retainer slide the .019 forward on the passenger side it needed for perfect lip alignment. Seal retainer is also marked both front to rear and side to side so the next guy has a chance. This is a viton rear seal fwiw. As I said earlier the first step of an engine build is to install the rear main seal and look at lip seal alignment.

 

[4406bbl]

On big blocks you also need to install the crank to see if the seal is actually touching on both sides of the block, I have never seen a small block with this problem.

 

[Huicho417]

I found this video that gave me a way of checking the contact of the seals on the crank.



After doing this to my engine, the upper seal seems to make good contact. Leaving a constant clean line where it wipes away the Prussian blue. The lower seal on the other hand leves an inconsistent line and seems like still leaves a film of Prussian blue behind.

 

[Huicho417]

What is the allowable end play for a 318 la engine?

 

[4406bbl]

.010 is max

 

[Huicho417]

That is the feeler gauge size I started with and did not fit. Kept stepping down until .008 fit a little tight.

 

[4406bbl]

Should be fine.

 

[Huicho417]

Well, after replacing the rms a third time and it still leaking I am throwing in the towel for now. Does not leak that bad so I put it all together yesterday and took it to a show today.

I will cruise it for several months to take a break and then I’ll attempt it again. The only thing I have not done up until now is try a rope seal. Seems like every time someone is in the same position I am in, the rope seal saves the day. Where can I get a quality rope seal? Also, can it be installed with the engine still in the car?

Thanks everyone

 

[Huicho417]

Back to the issue at hand.

I drove the car to several car shows and feel ready to tackle this issue again. I did find a rope seal from Best Gasket, which seems like a good product from all the reviews I have seen. Has anyone used this product before? The hardest part from what I can see will be to slide the rope into the block with the crank in place. Several suggestions I have seen is to loosen all the caps slightly to gain a little more room, after using the cap to preform the seal. The instructions also say to drill a small 1/16" hole in the cap groove to allow for a roll pin to keep the rope seal from spinning. If these engines came originally with rope seals and not a roll pin. Is it really necessary to add one now?