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Essex engine problems - again

Posted: Wed Jan 09, 2019 10:28 am
by TrevorG
Hi guys, apologies for yet more enquiries. As I have previously mentioned, I'm rebuilding my engine on a late 6a. In the 80s, robin rew did a lot of work on it for me and this is still the same original engine when I bought the car back, complete with bottom end noise. She is now dismantled, but I have two major questions if anyone can help. I have a mate who owns his own garage coming round to inspect the crank to see whether that needs regrinding or polishing.

But! we, and Essex engines in darwen, suspect that the bearings may be the wrong external size as they are all through the white metal. The only colour blob i can see on a journal looks off-white....could this be yellow faded?

Secondly, I've taken the timing gear off the camshaft but not the retaining plate. Camshaft can be pushed in and out about two millimeters, is this normal? And when pushed right in it seems to feel a lot heavier as if there is something behind. And then....the two bolts shown in exploded diagrams holding the retaining plate aren't bolts but Phillips or the like set screws. Is this okay.

Essex engine problems - again

Posted: Wed Jan 09, 2019 10:40 am
by scimmy_man
you need to have the crank measured,
the thust bearings can wear, giving front /back movement.

Essex engine problems - again

Posted: Wed Jan 09, 2019 11:12 am
by Coupe Racing
The cam does not have thrust bearings .
The 2 Philips screws are normal . Use an impact driver to remove

Essex engine problems - again

Posted: Wed Jan 09, 2019 11:33 am
by scimjim
yes, the camshaft thrust plate retaining bolts are cross headed countersunks.

Essex engine problems - again

Posted: Wed Jan 09, 2019 11:40 am
by scimmy_man
sorry I read crank not camshaft

Essex engine problems - again

Posted: Wed Jan 09, 2019 12:53 pm
by weaver
Hi Trevor, the camshaft will have axial movement but when when running it will be thrust forwards due to the distributor gear wheel.

Essex engine problems - again

Posted: Wed Jan 09, 2019 1:43 pm
by TrevorG
Thanks for the answers. I should have cottoned on to the camshaft being thrown forward due to the gear on it. When my friend decides whether the crank needs polishing or grinding we will then be measuring it, no need if being reground until finished. My main question though is how to tell if I need the oversize external bearing shells or the standard ones. Is it possible to use a vernier on a reassembled main bearing excluding shells?, or are the tolerances too small. Manuals all state the colour coding of the journals, hence my query 're the off-white blob.....alternatively, is there a specific place that the colour dot should sit? I'll try and photograph the colour blob.
Apologies for my lengthy waffling!

Essex engine problems - again

Posted: Wed Jan 09, 2019 1:57 pm
by Nigel Clark
TrevorG wrote:
Wed Jan 09, 2019 1:43 pm
Thanks for the answers. I should have cottoned on to the camshaft being thrown forward due to the gear on it. When my friend decides whether the crank needs polishing or grinding we will then be measuring it, no need if being reground until finished. My main question though is how to tell if I need the oversize external bearing shells or the standard ones. Is it possible to use a vernier on a reassembled main bearing excluding shells?, or are the tolerances too small. Manuals all state the colour coding of the journals, hence my query 're the off-white blob.....alternatively, is there a specific place that the colour dot should sit? I'll try and photograph the colour blob.
Apologies for my lengthy waffling!
A vernier gauge won't be sufficiently precise for measuring crank journals. Use a micrometer to measure to an accuracy of 0.0005" (half a thou). Using a micrometer will tell you:

- Whether the journals are standard (plus/minus some wear), or if its been reground.

- Wear and ovality, that is whethervthe crank needs (another) regrind.

- What size bearing shells are required if it's not going to be reground.


Nigel

Essex engine problems - again

Posted: Wed Jan 09, 2019 2:16 pm
by TrevorG
Hi nigel, I'm not sure how I get a micrometer to measure whether the block journals are oversize or standard. Do you mean the crank as that's easy but not what I'm asking.
Regards Trev

Essex engine problems - again

Posted: Wed Jan 09, 2019 2:24 pm
by roymck
If the crank is out bolt and torque the main caps back in and then use a internal micrometer to see if you have oversized main bearing housings , although the old bearing shells should be marked if block is oversize .

Essex engine problems - again

Posted: Wed Jan 09, 2019 2:31 pm
by weaver
Trevor, why are you suspecting that the O/D of the bearings are wrong. Can you tell if they have spun out of position. There should be no wear on the outside. And as roymck says, use a bore mic not verniers to measure.

Essex engine problems - again

Posted: Wed Jan 09, 2019 4:01 pm
by scimjim
shells always have o/s marked on the outside AFAIK?

Essex engine problems - again

Posted: Wed Jan 09, 2019 4:33 pm
by TrevorG
Right, took one big end and one main shell off so we can all see. The suspicion arises once you see the photos. The overall picture is of an engine that has recently been rebuilt.....so why the failure? 1...Ham fisted assembly, 2....badly run in, 3...bent crank, 4...wrong bearing shells....hence all the silly questions. Here goes with photos...
IMG_20190109_142327.jpg
IMG_20190109_142327.jpg (92.21 KiB) Viewed 643 times
IMG_20190109_142132.jpg
IMG_20190109_142132.jpg (116 KiB) Viewed 643 times
Here we see an engine that has hardly run in my mind, valves look similar. Second photo is the off-white blob....could be faded yellow.

Essex engine problems - again

Posted: Wed Jan 09, 2019 4:39 pm
by TrevorG
IMG_20190109_144339.jpg
IMG_20190109_144339.jpg (101.52 KiB) Viewed 634 times
IMG_20190109_144437.jpg
IMG_20190109_144437.jpg (105.79 KiB) Viewed 634 times
First photo shows crank main, not bad....second, the shell with white metal almost gone.


Third photo is big end on crank, fourth is big end shell....totally shot!

Essex engine problems - again

Posted: Wed Jan 09, 2019 4:44 pm
by TrevorG
Main shells marked.. Ford 732M6A338AS
Big end shells marked.... STD T/N 517815B

But who's to say if they are correct!

Will mic up an empty reassembled main. Anyone know the dimensions I'm looking for?