Part 3 Bottom End Rebuild:

Now the bit I’ve been striving to get to, yes the rebuild. The first job I wanted to do was to fit the camshaft. The reason for this is that the bearings are so delicate, and it would be very easy to damage them if I tried to fit the cam after some of the other engine components.
So I figured that I needed the best access possible whilst fitting the cam. I started by placing the block up ended on the bench, I then coated the cam bearings with the special cam lube that it was supplied with it, and very carefully lowered the cam into the block.

V8D H404 Cam	The cam as supplied. This is a H404 cam and is made by Kent Cams. I bought it from V8 Developments .
Cam to Block	Very carefully lowering the cam into the block. I made a real effort to make sure none of the lobes came into contact with the new cam bearings. Also you can see the special lube on the cam.
End Bolt	When fully home, I fitted the end bolt and carefully turned the cam to make sure there was no binding. Only moderate effort was applied, and the cam felt nice and smooth as it turned.

It’s all going very well up to now. Or so I thought. Keep reading.

The next job was to clean the crank again to make sure I’d got rid of the entire Plastiguge residue from earlier on.

And here it is, fresh out of the washer ready to be dried off and fitted to the engine.	Clean Cam
Just before fitting the crank, I applied plenty of nice clean engine oil to the new shell bearings.	Adding Oil

Then it all went wrong. I very carefully lowered the crank into the block, and feeling a bit smug and very pleased with myself, discovered that I couldn’t spin the crank through its full 360° travel.

Oh dear what’s gone wrong?

Well on closer inspection it was obvious that the problem was with the counter weights either side of N° 3 main journal.

They were catching part of the casting on the block.

I dragged the old TVR block back out, and on comparing the two side by side I could see where TVR had removed this material.

How did I miss this? I’d compared the blocks side by side many times but for some reason it just didn’t occur to me that this would be a problem.

Oh well I’ll just have to remove the crank, cam and main bearing shells, and sort it out.

As I was feeling rather annoyed with myself for missing such an obvious difference between the blocks. I decided I wasn’t in the right frame of mind to tackle it there and then.

I decided the best thing to do was to leave it and make a fresh start the following day.

And here is the offending item. There are 4 of these casting marks. Two on this side and two on the other.

Offending Part

This has caused a lot of extra work, as I now have to remove the bits I’ve fitted and tackle the castings with the little Dremel.

Then because of all the filings and swarf I’ll have to clean the block and all the other parts all over again.

Well I did say I was going to treat the project as a learning experience, and I certainly learnt a lesson today.

NEVER ASSUME ANYTHING.

I removed the cam and main bearing shells and set about removing the material.

A couple of hours later and it’s looking pretty good.	Material removed
And now from the other side, you can see how I’ve had to remove material from around the oil pickup casting.
Time to start again. These parts have all been thoroughly re cleaned and are ready to install for a second time.	All Clean again

It took a good few hours to grind that material away, as I had to keep re fitting the crank and checking. I was looking for around 1mm of clearance, and used a feeler gauge to measure the gap. I also used the old shell bearings while I was grinding material away, as it wouldn’t matter if I caught them with the die grinder, or if they got swarf on them.

Very Close	This photo shows just how close the counter weight gets to the side of the block on its way around. The weights on the TVR crank must be a lot bigger than the standard 4.6 cranks.
How Close	It’s difficult to show it clearly, but there is enough clearance now, and the crank spins nice and freely.

 Now that I’m happy that the crank can turn freely I re fitted the new shell bearings and the cam, so I’m back to where I was a day ago.

With the cam and crank fitted the next job is to fit the new shell bearings into the main bearing caps. They are fitted in exactly the same way as the ones in the engine, i.e. locate the tab, and with light thumb pressure push them home.

Again there is a slight difference between the parts I removed and the new parts, in this case the thrust bearing-locating tab didn’t quite line up with the slot on the cap. As it’s a thrust bearing and therefore has sides on it, I just filed the slot until the bearing fitted.

The problem is that in the TVR engine, and older Rover V8’s, the thrust bearing is only fitted into the block. On newer engines the thrust bearing is fitted to the block and the cap. This should be a good thing as it gives the crank a much larger area to run against.
    
So I think its worth a bit of effort to make the bearing fit. Besides that’s how the new bearings were supplied so without buying another set I had little choice really.

I should have covered this when I did the bit about checking the clearances as that’s when I realized the thrust bearings were different, but for some reason I forgot. Sorry about that.

I just had to take a bit of material out of this slot so that the tab on the shell bearing would fit.
As I’m trying to build a strong bottom end, I decided that rather than use the standard bolts, I would use ARP studs instead. These studs allow much higher torque settings to be used and in theory should keep the crank more stable.I started by cleaning all of the bolts and nuts, and then applying a just a small amount of light oil.	ARP Stud Bolts
Then I screwed all of the studs into the block, just finger tight.	Finger Tight
By putting 2 nuts onto the stud and tightening against each other I could then torque the stud down to the manufacturers recommended setting. Which in this case is only 4 ft/lbs. not much more than finger tight. Luckily for me my smallest torque wrench starts at exactly 4 ft/ lbs. so at least I know all the studs are the same.	Torqued to 4 ft/ lbs
As with the shells in the block, a light coating of engine oil before fitting. Making sure I don’t get any oil onto the machined surface where the cap meets the block.	Lightly oiled
Place each cap over the studs, making sure they’re in the right position and the arrows on the caps face the front of the engine. I lightly tapped each cap down with a soft-faced hammer.	Cap Placement
The rear cap, N°5, has these small seals at each side, they’re commonly known as crucifix seals and they’re tapered so will only fit one way.	No.5's Crucifix Seals
Before fitting the rear cap, the rear oil seal must also be fitted to the end of the crank. I put a very light smear of oil on the rim so it would slide over easier.	Rear Oil Seal

 Once all the caps were fitted, the fun started again. I nipped all the caps down and kept turning the crank as I went. So far so good, no sign of binding and the crank felt nice and free.
The torque setting for the studs is a pretty tight 85 ft/lbs (the standard bolts are only 55 ft/lbs) so I started by torqueing each nut to 50 ft/lbs to start with. The crank was still nice and free.

Then I went to the full 85 ft/lbs. Guess what? The crank was binding.

So the next job was to find out which bearing was causing the problem, I had a gut feeling that it was N°3, the thrust bearing, so I loosened that one off.

For once I was right, with the other 4 caps at the full 85 ft/lbs the crank felt lovely and smooth. As soon as I put any reasonable amount of torque on cap 3 the crank would start to bind.

Remember this is the cap I had to modify to take the new type thrust bearing. On closer examination I could see that the bearing was not quite flush with the cap, so I decided I would take a bit off the edge and keep re trying it.

If it all went pear shaped I’d just have to buy another set of bearings and fit a plain one to the cap instead of a thrust type.

By this time I’d asked my mate for a second opinion, and he agreed that the bearing wasn’t quite flush. This is him removing a bit of material from the edge of the shell. We’re literally talking fractions of a thou here. Just a couple of strokes with the file and re fit and try again. It took about 15 attempts before we were satisfied that the crank was free. Then to be doubly sure that the clearances are still ok, we checked them again with the plastigauge and found that all was well.	Fine Filing
And here it is. The bottom end all buttoned down, tolerances double checked and a nice free crank. Just the side bolts to do, but I need to find out what the torque setting is first.	Bottom End Bolted Down
Once the caps were all tightened down I noticed the crucifix seal sitting above the cap face. A sharp knife soon sorted that out.	Gently now
By now you’ve probably realized that I’m a bit obsessed with keeping the working area clean and tidy. Well it’s true, but it could be a few days before I get time to work on the engine again. And now that it’s got oil on some of the surfaces, any dust will just stick to the oil and I’ll never get it out.	Thanks Mrs Quinn ;-)

The wife won’t be too happy though when she finds out I’ve pinched all her Clingfilm. She still hasn’t found out about the cam bearings in the freezer.

The Cross-bolts and new Doughty seals for the sides of the block.
Cross-bolts now fitted and torqued down to 35 ft/lbs
Time now to fit the pistons, I found the easiest way was to do one side at a time and to tip the block on its side like this.
A piston and with a full set of rings waiting to be fitted before it can go into the engine.
Start by fitting the oil control ring into the 3rd groove down. The ends should butt together and be in line with the gudgeon pin when it’s seated.
This is where the join is.
Next the 2 thin rings which go either side of the oil ring.
The join should be about 40mm away from the oil ring join.
And the join on the bottom ring should be about 40mm on the other side. I’ve marked where the ends of the 3 rings are. To the left is the top one, the middle mark is the oil ring and the mark on the right is the bottom ring. Also make sure the rings make a proper “sandwich” and that they don’t cross over each other at any point.
Next the bottom compression ring. This ring fits into the second groove down from the top, and I lined up the join on the opposite side to the bottom rings. Make sure you follow the instructions and get them the right way up. There’s a bevel that must face the top.
And now the top ring again the join is directly opposite to the second ring. Oh by the way I haven’t stretched the rings by as much as it looks, it’s just a trick of the camera due to the ring being closer to the lens than the piston. You only need to open the rings enough to get them over the piston and no more.
And there we have it all rings fitted and ready to go into the engine. You can clearly see that the top ring is made of a chrome material.
Now I slotted the piston into my well-lubricated piston ring compressor.
I then made sure I put plenty of clean engine oil all around the bore. I also numbered each piston and cylinder to make doubly sure of getting everything in the right place. I know it may sound a bit over the top but when you have to work on the engine from either the top, bottom, left or right side, it saves having to think too hard.
Using the wooden shaft of a hammer I gently tapped each piston into place.
The piston just coming through. Although it doesn’t show it in this picture, I actually turned the crank so that the journal is as far away from the con rod as possible. This saves any unwanted contact between the big end and the crank journal.
A drop of oil on the journal fit the big end cap and the jobs a good one. Only 7 more to do. The bolts are torqued to 38 ft/lbs.
Plenty of oil in each cylinder and slowly turn the crank after each piston is fitted. There is an opportunity for the bottom of the piston to come into contact with a cam lobe, so great care must be taken when turning the crank. Fortunately I found a position for the cam that avoided all contact.
And here we have it. The complete bottom end.
And from the top end. The engine has now been remounted on the stand. As it will no longer sit flat on the bench with the crank and pistons fitted.

 The next job that needs doing is the cam timing. This is not the easiest if things to describe in detail, but with the help of a few pictures I’ll give it a go.

The first thing that needs doing is to find true TDC (Top Dead Center) for N°1 piston. What do we mean when we say true TDC? Well the piston has duration. When it reaches TDC it stays there for so many degrees turn of the crank before it begins to descend again.

I need to establish what this duration is before I can find true TDC. As an example if the duration is 10°, true TDC is 5° after the piston first reaches TDC.

I find the easiest way to find True TDC is with the dead stop method. The dead stop is a mechanical stop placed across N 1 cylinder bore. The crank is turned clockwise until the piston hits the stop, a reading is taken from the degree wheel attached to the crank and noted down. Then the crank is turned anticlockwise until again the piston touches the stop; again the reading is taken down.
The 2 readings are added together and then divided by 2; the result is the N° of degrees the piston is either before or after TDC when the piston is in contact with the stop.

	This is the dead stop I made from some 5mm flat bar.
Across No.1	Now the dead stop fitted across N°1 cylinder. The bolt in the center is the contact point for the piston. And can be screwed in or out as required.
Homemade marker	Then I fitted the degree gauge to the crank, and bent up a piece of wire as a marker.
Piston meets bolt	The crank has now been turned clockwise until the piston makes contact with the bolt.
20° BTDC	A reading is then taken from the degree gauge and pointer. In this case 20° BTDC. I know it’s 19.5°, but I’m working to whole numbers.
10° ATDC.	This time the crank has been turned anticlockwise until the piston makes contact with the stop. As you can see we’re at 10° ATDC

So the calculation is 20 + 10 = 30.   30 divide by 2 = 15. Therefore when the piston is in contact with the stop no matter which side, i.e. before or after TDC it must be 15° from true TDC.

All that’s required now is to re position the degree gauge to 15° BTDC. This must be done without the crank moving.	15° ATDC
And by turning the crank anti clockwise until the piston hits the stop, I’m now 15° ATDC.	15° BTDC

To double check my figures, I wound the adjuster on the dead stop out a bit, and this time I was 8° before and after TDC when I turned the crank so that the piston was in contact with the bolt. Now I’m sure that when I remove the dead stop and turn the crank to TDC on the gauge I will be bang in the center of the crank duration.

Using the lever to turn the crankshaft. Made life so much easier.	Levering the Crankshaft
The camshaft I’m using is timed at 110° ATDC. This means that the cam should be in the middle of its duration at maximum valve lift on N°1 inlet, whilst the crank is 110° after TDC.	110° ATDC
I set the crank to 110° ATDC and marked the rear of the crank to make life a little easier. The other mark is TDC.	Crank Markings

No1 at full lift	Piston N°1 inlet valve at full lift.
Woodruff keys	Now that the follower is at its highest point I re fitted the woodruff keys to the cam and the crank.
Crank Sprocket	Then I slotted the new crank sprocket over the shaft.
Chain applied	Then the cam sprocket and chain were fitted.
Spacer refitted	Refitting the spacer.
Distributer drive gear	New distributor drive gear.
torqed to 43 ft/lbs.	And then the center bolt and washer, the bolt is torqed to 43 ft/lbs.
110° ATDC.	All that remains now is to check and double check that center of full valve lift is achieved at 110° ATDC.