Algy

Hi Haggis, It is one of those things, I can only go with my experiance from the old cars I have had to deal with and what has worked for me. I don't know how well SI5980 would work. It sounds like you are doing all the right things, the thing is with the hot retorque is not to drive the car hard until it is done, or the gasket damage is done and in the case of these engines and Jag's not to rev the engine to produce an oil pressure of over 100psi for any time until the retorque is carried out or they can blow oil onto the gasket face (even with sealant) and the seep can not be sorted if it starts. I am with you all the way a cloth saves a lot of time and cost and a seep is not major. My old British bikes all leak and as I have been told by so many "If it isn't leaking fill it up quick". I did get one not to leak from engine casings (only from the seals) by using aircraft sealants after remachining the faces, I would hate to strip it again though!

Sorry to hear that Haggis, but I still would not use an instant gesket, standard or even high temp silicone sealants are not good in thist type of application from my experiance. Hylotyte Red has worked very well for me. The thing is the oilway is so small and even at over 100 psi should not have enough pressure to escape, unless blown out by combustion pressure across faces (in you situation were both block and head are flat). The most likley cause of that is washer bow, the only other thing I can think of is an out of cal torque wrench. You say you retorqued your head, did you undo the nuts and retorque and do it with a hot engine? I ask as just torquing can in some cases not allow the head to settle but as the oil way is at the end of the block even that is unlikely. As for around the pushrod holes there should be very little pressure there to force oil out, even if your engine breather system is faulty, the problem with using added sealants is that you reduce the crush pressure some were else ( learned that to my cost with copper head gaskets, for vintage race engines, with those it was coat the whole thing or use nothing).

A little more work done. P1 Note the studs have a grove in the end that screws into the block, I used new studs. Part of my prep, was to fill the stud holes with brake cleaner and sock it up with tissue and repeat until the tissue comes out clean, with no signs of oil. P2 I use the two-nut method for fitting studs and “Studlock A70”, tighten the nuts together and then fit the stud by spannering it down with the top nut then use two spanners to slacken the nut from each other and unscrew them by hand. P3 Fit the studs, you do not need to tighten them to much about half the nut torque is the general guide (making sure they are fully seated), unless using self-locking nuts; as the stud tension / hold is carried out by the top nut, if you over tighten then you can throw up a ring around the base which can interfere with the fit of components, unless the is a recess bored for this (which there is not on my engine).

It depends on the gasket you use the pressed metal ones I would use “Hylotyte Red”, not instant gasket or “Loctite 574”; for a compound gasket there should be no need, provided both head and block are flat! If retorquing undo all the nuts ½ a turn, in the opposite order to the tightening sequence then retorque run engine up to temp and retorque again.

Convertion for lb/ft to Nm multipy the lb/ft by 1.356.

So, time to get timing. P1 Checking the clearance on the Cam retainer as this will determine the camshaft end float. I had 0.004” the limits given are 0.004” to 0.008” P2 The camshaft is fitted after having a drink of assembly oil (I use Millers competition engine assembly oil). As you can see from the crankshaft sprocket the engine is being built with a duplex timing chain, it was modified to this some time in its history so all I am doing is replacing it like for like, I assume the original was out of a 2.5 but it makes sense with the higher lift cam. I was going to use a Mk2 cam but opted to use this one, which matches the original fitted (and came with the car). P3 I checked the alignment of the sprockets, no shimming needed. P4 In go the cam followers, after a quick swim in lub. P5 From the information on an oil soaked piece of paper, I found out that the max lift for the inlet and exhaust is at 107Deg either side of TDC. So first off was to determine the max lift points and mark the can wheel. To do this I used an old cam follower upside down and a DTI and the bracketing system (for both inlet and exhaust) the same way as I determined TDC. P6 So I use the flywheel ring gear as a protractor, it has 117 teeth so each tooth is 3.08Deg so nearly 35 teeth each side. P7 Having set up the cam for the exhaust max lift and the crank at 107 BTDC, I turn the crank through to 107 ATDC and check the inlet is at the max lift point and as I divided the cam wheel marks, I could check at the TDC point as well. The photo was taken after torqueing the bolts (24lb/ft to 26lb/ft) and locking the bolts with the tab washer, the actual result showed an error at the crank so small that I could not see it, having said that I had to wipe the marks off the cam wheel and go through the process a second time to get the bolt holes to line up. Note this is not the method for the standard cam, as I don't have the figures for those, I can not say if this method would work for them! P8 & 9 Getting some of the ancillaries on, the fuel pump first, which I had refurbished and has new diaphragm and valves fitted, was fitted and torqued (12lb/ft to 14lb/ft). P10 & 11 The crank case breather plate with blanking plate, obviously a mod carried out when a later inlet manifold was fitted but keeping the breather to be able to revert back, so I have fitted it as it was (inoperative), of course torqued on fit (12lb/ft to 14lb/ft). P12 Setting up the distributor drive is a bit of a pain as you need it to finish up in this position but it urns as it goes in and you have to also set the oil pump drive to line up. My method was to first get the drive to engage with the cam to finish in the right place, with the oil pump drive about lined up with were the slot on the drive would end up, and tried it out but when it didn’t engage with the oil pump, so I lifted it slightly and turned the crankshaft to turn the drive and kept on trying to engage it to the pump until I was successful. P13 The fitted the pedestal with 6 Thou of gasket and torqued it down (12lb/ft to 14lb/ft).

Oh yes ? I am lucky my crank has just been reground and balanced.

2thou! If we are talking the distributor drive 0.003” to 0.007” is 4 thou in my maths. Thankfully my one needed to be packed to get the clearance. I don’t see why it needs to be that close as the distributor is driven in one direction only by the cam, so I can’t see any problem with your Spitfire.

Okay so, I continue with the engine build, getting it ready to take the camshaft. P1 I only use a drip of thread lock, there is no need for any more. P2 The flywheel in bolted on and torqued up, I bolt a bar to the flywheel to stop it turning (sorry no picture of it). P3 With the flywheel on I checked the runout. This is done with a DTI as in the photo (within the area that the friction plate acts), then I apply pressure on the front of the crankshaft (so the crankshaft end float id taken out), as I turn it through two full turns. The reading I got was <0.001” the maximum permissible is 0.003”. P4 I Then carried out a TDC check, with a DTI on piston 6 and used the bracket method to confirm the mark on the flywheel matched the plate. What is the bracket method, did I here someone say? Well I turn the crank and mark the flywheel when the DTI gets to a measurement that I record (it is not important what it is) and then I carry on turning the crank until I have gone past TDC and the DTI drops down to the measurement recorded earlier and mark the flywheel again. I repeat with a different measurement, and then find the point between the first marks and check it is centre between the second set and that is the true TDC point. My flywheel was accurately marked. P5 I wanted to get the over piston volume so that the combustion chamber volume can be set to give the correct compression ratio. It was done with a piece of Perspex with a small hole and filled with a pipette. I got a volume of 4.4ml so this along with the gasket volume of 7ml I have to subtract 11.4ml from the clearance volume to give the head chamber volume. P6 Next up before fitting the cam was to check the distributor drive clearance so I checked the thickness of a ½” washer (0.060”). P7 Then with it on the drive gear, held in place with light oil. P8 The with the gear in the block and the housing on top, I measured the gap and got a figure of 0.061”, so will use 0.006” of gasket to get a clearance of 0.005”. The tolerance in the manual is 0.003” to 0.007” but show calculations for 0.005”.

Hi Paul, I thank you and the others for your interest in my little project. I have edited the post to include the information for others but have also included it here for you. I used 0.005” oversized thrust bearing to get a end float figure of 0.006” which is the low end of the acceptable limit of 0.006” to 0.008”. Regards Algy

Sorry did not put the main reason for the sealant combination. By using the combination of sealants and a paper gasket, it allows you to take the sump off should you ever need to without distorting the flange. This is also why a reason I use the gaskets as some would go for a straight 574 joint but this leaves little space to get anything in to cut the joint and allow removal of the component at a latter date. It makes an excellent seal, especially on CNC machined engines, hence the use on a lot of modern engines as they have a long service life and more often then not if they have a component failure it is masked by the ECU until it becomes catastrophic.

So back to work! P1 I cut away the excess high temp sealant and cleaned it out of the holes. P2 Loctite 574 applied to both sides of the front plate gasket, you need the gasket as this affects how far forward the camshaft is. P3 The front plate fitted with temporary bolts fitted in place of the timing cover, to ensure the plate is seated, all torqued up. P4 The rear plate fitted dry (no sealants) and torqued up. P5 The oil pump seat with a very thin film of Hylomar sealant. P6 The oil pump fitted and torqued. Those in the know will note it is a Mk2 oil pump but this is what was fitted, in the past as it has a higher flow rate than a Mk1 oil pump. All too often people fit increase pressure by over shimming the pressure relief valve but that doesn’t address the problem of flow rate and can actually wear an engine faster. P7 Now I lay down a thin line of Loctite 574 in the area that will be covered by the inner half of the sump gasket. P8 Then I fit the sump and tighten the bolts working from the centre bolts on the long sides out in a similar manor to the way you would torque down a cylinder head; I do it in three stages, up to the final torque. Why high temp sealant and then Loctite 574? Well Loctite will not air dry and is not a good gap filler, so will not fill the flutes in the sump flange, the silicone sealant air dried, filling the voids and ensuring the gasket was flat on the block. I use the 574 on the block side as it bonds the gasket and produces a good seal also if penetrates the gasket paper.

No Pete, I don’t prefer high temp silicon to 574 but I use it on sumps (and only sumps and then only partly), you will see what I do in the near future and I will explain why then. ?

These engines come from the 60’s, well before CAM and so the heads are all different. Most tubular exhaust manifolds are made with the ports with a slightly larger cross section area, they really work when the head is being ported, that way the head ports can be matched to the manifold. I use Perspex to do the matching (see the two attached photos). I first pick up the studs on the Perspex and then use those to align the Perspex on the manifold and use a rotary tool to get the patter off the manifold. I then transfer this to the head and mark it out as you can see in the second photo. You would need to use a suitable rotary grinding tool to then dress the head back as smoothly as you can back into the port at least as far as the valve guide. It doesn’t have to be polished just fairly smooth. Of course, you would do this work on the head with it removed and with the valves out. Without this work more than half the work you have done will be lost by the bad match on the ports and the gas flow in the port.

Some more photo’s then. ? This is how I prepare a sump. P1 Without the oil pump fitted and with the crankshaft turned to reduce any big ends sticking up too far. I cover the lower surface of the block with cling film. P2 Then The gasket is placed on top which has already had a smear of high temperature gasket sealant spread on the top only. P3 I use masking tape around the outer edge, then I apply sealant to the sump face to fill the flutes and all around the inner edge. P4 Then the sump is placed on top ensuring all the holes line up and then I use weights to press it down, this expels the excess sealant inwards and out. P5 Once happy the sealant has been forced out, I remove the tape, while the sealant is still uncured. I then leave the sump like this for at least 24hrs, for the sealant to cure. The reason for doing it like this, is to ensure the gasket line conforms to the lower face of the block.

Hi Doug, It is an aluminium alloy one. These should not cause any problems as long as they are fitted correctly, most of the distortion is due to over tightening the sump with the bridge incorrectly aligned with the block and not supported by the front plate. But I do agree with you why make it with wood seals at each end, but there are other engines I have seen with some strange joints on crankshaft ends.

Thanks for the feedback. I did not want to bore people.

Hi, Looks like you have made a good job. On the point of square to round. A sudden change in cross section will cause a distinct slowing of the exhaust gas at that point, this will seriously affect the exhaust scavenge that you have worked so hard to improve by equal length primaries. I match my exhaust manifolds to the head on all the performance engines I work on. Some inlet manifolds can benefit in having a small step of 0.5mm evenly around them at the head interface to help tabulate the atomised fuel to encourage vaporisation. (Triumph 6 cylinders are one.)

More pictures and explanation! P1 Build oil applied to shells. P2 Checking the crankshaft end float. Additional note I used 0.005” oversized thrust bearing to get a end float figure of 0.006” which is the low end of the acceptable limit of 0.006” to 0.008”. P3 I smear build oil on the big end caps and loosely fit the bolts so I can turn the engine over. Also at the same time I prime the crank shaft oil ways with engine oil. P4 Next I fit the Main Bearing caps, again having smeared build oil on the shells first and lightly tighten. Then I torque them to the lower torque figure 55lbs/ft from the front to the rear, leave for 15mins and turn the crankshaft over then repeat at a mid-torque figure of 57.5lbs/ft on my digital torque wrench this allows for torque tolerance. P5 Next it is the big ends turn and I remove the bolts apply a drip of thread lock and torque them to 38lbs/ft then 40lbs/ft, turning the engine over after each pair have been torqued. P6 Applied Loctite 574 to the rear seal gasket spread it so I have a thin film on both sides. P7 Give the rear of the crank a little drink of oil before the seal goes over it, as you can destroy the oil seal on first start if the seal is dry! P8 Sorry for the photo but you try and take a photo at the same time as doing the work! I lightly fit the bolts then make sure the joint is alighted with the block. The torque it up to 17lbs/ft. P9 Trim off the gasket that is above the joint. P10 Onto the other end. I fettle the wood blocks to fit the block and reduced the chamfer they came with. P11 I have test fitted the block as it was new (the original was missing), to make sure it was flat to the block and had to dress one end. When I was happy, I used some more Loctite and then fitted the block loosely. P12 A drip of thread lock and then fit the wood blocks with the chamfer facing into the sealing block and the gap and wood prepared with Loctite 574, then tapped them in with a wooden mallet. P13 Trim off the excess and then it is on to checking the alignment P14 & 15 P16 Finish of by torqueing the screws to 13lbs/ft then retrim the wood and gasket and recheck alignment. Do let me know if I am going into too much detail.

Some more photo’s! P1- The piston with the rings fitted getting a drink of engine oil. I don’t use build oil on the pistons do the viscosity being too high and causing extra wear on start up. I will set up the ring gaps so that the compression rings are 180 degs apart and the gap aligned with the crankshaft, as the oil control is a multi-ring type I set these up with the gaps about 5 deg either side of the butt joint on the centre ring and on the left side of the engine. P2- Me trying out a cheap ring compressor (a friend has borrowed my nice ones) and it worked okay, just make sure they are bedded down on the top of the block before putting the piston down (yes, I push them down, not the normal hammer handle tapping system that can stop you feeling the ring catch). P3- The pistons in and ready to turn the block. It would be easier on an engine stand but my one will not fit on this engine and also has a XK140 engine on it in my main workshop. P4- Shells being fitted to caps. Make sure the joint between shells and cap is clean and degreased, this helps ensure no hydraulic action during build, which can lead if no check torque carried out to bearing spin. P5- The same goes for the shells going into the block and rods.

My next step is to check the piston rings. The first picture shows how my new rings came packaged, which had them sorted into sets and the position on the piston. The second picture shows that the rings are marked top, so you know which way up to fit them. The third photo, shows how I check the ring fit so I can measure the end gap. My engine has had a re-bore so I can do this near the top but normally I would have the ring about an 1/4 inch down the bore. I use the piston to ensure the ring is level. The manual gives compression ring clearances different to the figures given with my pistons as they overlapped I adjusted them to conform to both (0.0025"), using a fin diamond dressing file (driven in from the outer side of the ring inwards so any bur in by the piston and can be cleaned off) and the rings are then cleaned before fitting to the piston. (The gap looks bigger in the photo because I moved the ring from level to be able to show it better)

The conrods have been balanced both in weight and end to end as have the pistons. Note I had already checked the small and big end alignment and replaced and reamed the small end bushes (details of how to do this is in the manual). In the first photo you can see how the rods are balanced. The second photo shows all ready for assembly, you can see the piston weight marked on top. The third shows the rods fitted, do make sure the circlips are correctly seated as there is nothing worse than having one try to go AWOL and score your nice bore. You should always check the pin fit in the small end and piston before and after assembly.

You are right just looked again. On the first look I thought it was the end of a second con rod. Oh well I will hide under a rock.

Looking at the pictures it is a nice paint job but looking at the picture with the big ends (picture 10) the shells are not the same!? So has been rebuilt before and not to a good standard. A good paint job is not a guarantee of a well built engine, so from the photo's the engine for me would need a full rebuild on, with possible regrind and rebore; at the start price without all the other expensive bits on the outside, the price I think is on the high side (but that might be being tight).

Some of my engine build on the Bond might help you, as and when I progress the egine rebuild. It is a Mk1 but most of the build is the same. I will try to take more photo's to help. Just like you I am trying to build this engine in the spec it was in when I got it (as it was in the 1970's when raced), which was tuned but not hot.