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Anon
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Char Lottie's cooked engine Part 3 cylinder head
A good third of the budget for the job went on this -
4 exhaust valve seats for LPG fitted, re-cut inlet valve seats, reface all valves & lap in; 8 valve guide sleeves (K-Line); gasket face surface grind.
The reasoning behind not fitting inlet valve seats is based on the fact that the inlet valves run cool enough to make use of the original seats re-cut. That and another £100 or so...
Valve head numbering is to ensure that valves stay with the seats they've been lapped to; numbering is from the back of the head rather than the front.
From the top -
This being the first CF head that John at J&E has done, a bit of experimenting with the cracked head was in order to determine the best seats to use and also confirm that valve guide liners could be fitted rather than ream out the guides & fit valves with over-size stems, if they could be found.
Like so -
Inlet counterbore (larger one) has been over-bored as far as breaking into the water jacket to check wall thickness when bored to fit a seat. Pass. 
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 Sat 06 Feb 2010 @ 23:49
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Anon
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Cylinder head, assembly
Gaskets -
Surplus gaskets from the Gaskets-direct set -
These are for FD/FE Victor, Ventora & HC Firenza, Magnum engines (single & twin carburettors).
Valve springs, caps, collets -
Rotator caps are for the exhaust valves. Inlet valves have plain caps.
Out of 2 sets of valve springs the one from Skoota's engine came out ok for free length -
The springs from Char's engine were well under, probably because the engine cooked.
First thing to do was fit the inlet valve stem seals -
Valve stem & face were lubricated, valve, springs & cap fitted in the head & then a valve spring compressor was used to insert the collets -
Inlet valve of number 4 cylinder was the first to be fitted.
I tend to use a compressor designed for deep skirt cylinder heads because it centres more easily than a conventional fork end compressor.
A dab of grease helps stick the collets in place, taper downwards. Fumble fingers me needed tweezers & just-so adjustment of the compressor to get the collets in right; not something that bothered me in my younger days...
Anyroadup, once the compressor was released & the collets looked to be seated right a few dings with a hammer on the top of the valve stem made sure, valve & spring covered with a cloth first in case a loose collet flew off to ricochet anywhere.
Inlet valve done, then exhaust valve -
Then the same again for the valves for cylinders 2, 3 & 4 -
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Wed 10 Feb 2010 @ 17:20
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Anon
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Fit camshaft in housing.
Camshaft assembly starts with fitting the camshaft into the housing from the front; I found this easiest by clamping the housing front uppermost in a woodworking vice & easing the camshaft in with the bearing journals lubricated with fresh oil.
End cover aligned to fit studs & thrust plate engaged with cover peg so that the plate can be correctly positioned in the cam housing. Using a dab of grease in the housing prevents the plate from falling out -
Thrust plate can be re-aligned once the centre bolt & large washer are fitted - Loctite 243 threadlocker, camshaft wedged with a piece of wood at a cam lobe - and the grease should keep it in position while fitting the cover. Centre bolt is 3/8" UNF, 5/8" long, 9/16" AF head; tightening torque is 34 lbft (46Nm).
Cover is first fitted without its gasket and using 3 plain nuts (5/16" UNF) in order to tighten the cover evenly to trap the thrust washer against the cam housing. This is for checking camshaft end float -
0.16mm is at the top end of 0.03 to 0.18mm (0.001 to 0.007in) but it's enough leeway to not have to worry; camshaft thrust washer wear usually isn't a problem area & most times what end float exists is what the engine left the factory with.
A spray of glue both sides of the gasket (hung on a wire hook for spraying second side) -
Wait 10 minutes or so ... then realise the shed was too cold for the glue to work. Duh. So go find something else to do for an hour or three while everything including the cam housing warmed up indoors & over-spray was nicely sticky, then re-coat to be sure.
Anyway, gasket faces cleaned & gasket stuck into end cover, then cover fitted using new 5/16" UNF nyloc nuts -
The cover only needs to be tightened to trap the thrust plate; any more distorts the cover. (New nuts aren't always necessary but I've got plenty yet.)
The gasket from the Gaskets-direct head set seemed a bit thin compared to GM ones but was compressed all round by the cover enough to seal. We'll see how long this gasket lasts; hopefully the glue will prevent it from squeezing out & thinning in the process, something that even thicker GM ones will do in time.
If a gasket won't compress all round then the cover will be bent around the stud holes & needs replacing to be sure that the gasket won't leak.
Camshaft front oil seal, lip greased, was easy to bump in evenly & flush with the front of the housing using a soft face hammer -
Seal is identical to the auxiliary shaft seal: steel shell single spring-loaded plain taper lip type, 2.504" diameter & 0.375" thick; shaft diameter (for lip working diameter) is 1.75".
Last thing to do before fitting the tappets & setting up valve clearances is fit the front bolt & thick washer with enough extra washers to make up about the same thickness again as the original washer -
This is to prevent the bolt from bottoming in the camshaft threads when used to turn the camshaft once it's assembled to the cylinder head. Bolt is 3/8" UNF, 7/8" long, 9/16" AF head. Leaving the thick washer as found is best (usually they're bent); straightening it out can crack it & it could split in two when used again.
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Wed 10 Feb 2010 @ 23:59
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Anon
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Tappets; bench valve adjustment.
Before the tappets could be refitted the stem protrusion H of each valve was checked -
Cylinder 1
Exhaust - 1.068"
Inlet - 1.099"
Cylinder 2
Exhaust - 1.072"
Inlet - 1.10"
Cylinder 3
Exhaust - 1.074"
Inlet - 1.095"
Cylinder 4
Exhaust - 1.072"
Inlet - 1.10"
I think that J&E have done well to keep the exhaust valve stem protrusions close to spec. of 1.07". This figure was arrived at by assuming that maximum valve protrusion allowed of 1.13" went with -0.06" 2nd under-size adjuster screws. It does, but only when the adjuster screw is only a few clicks away from the limit of its travel as I found out when the exhaust valve tappets were fitted with their original standard size screws & the camshaft was assembled to the head.
The screws landing about mid-way across their tappets is a lot more comfortable because this gives about 0.018" of adjustment each way, so bedding in wear can be accommodated (clearances open up) as well as valve/seat wear (clearances close up). However, then came a problem: I couldn't find the 1st & 2nd under-size tappet adjuster screws that I'm sure I've got somewhere, like 2 & 3 here -
I was stumped for simply fitting under-size screws all round then. The solution was to grind ~0.03-0.04" from the inlet valve tappet adjuster screws as well as ~0.01" from the exhaust valve tappet adjuster screws (about what they need to remove wear recesses anyway). In the process, rather than take the inlet valve tappet adjuster screws straight down to an under-size (-0.03" or -0.06") I ground just enough off each screw so that when the valve clearance was adjusted the screw landed mid-way across its tappet.
This meant assembling & re-assembling the camshaft to the head a number of times, each time cleaning everything spotless to avoid grit getting in. All this was done without a gasket; minimum thickness to allow for compressed gasket is 0.003".
Several hours later, the last screw was finished with about 0.04" ground off -
The slight increase in taper angle compared with the standard screw is deliberate: taper should be 35degree for 1st under-size, 42degree for 2nd under-size. Grinding off the flat end (ID for standard adjuster) makes it a lot easier to get somewhere close so that each click as the adjuster is turned gets about 0.003-0.004" of adjustment.
Final bench assembly with everything cleaned one last time & freshly oiled -
Last valve clearance check for now, 0.007" max. (0.003"+0.004" blades) for inlet, 0.015" max. for exhaust (to allow for ~0.003" gasket thickness).
And where the adjuster screws landed -
So, head & camshaft are ready to fit to the engine but maybe a re-think is needed on what to specify for valve stem protrusion when having seats fitted. Time to decide on a re-think is final valve clearance adjustment once the engine is running & has thoroughly warmed up; clearances have a habit of opening up once a rebuilt engine is running.
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Sun 14 Feb 2010 @ 00:29
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Anon
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I must admit that is one of my to do jobs when I start the van up and running again in a couple of weeks. I had found that I had a bit of a constant tap at the end of the season last year so I want to double check if things have moved. Would the new seats etc. be affected if the clearances remained out?
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Sun 14 Feb 2010 @ 10:51
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Anon
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Tapping occurring after a head job usually is things settling in & if anything wide clearances help valves to seat; it's clearances too small that can cause valve & seat damage.
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Sun 14 Feb 2010 @ 23:35
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Anon
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you know me...if anything makes the smallest noise I have to adjust! Shall I leave them for a bit then Phil?
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Mon 15 Feb 2010 @ 08:41
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Anon
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Follow your instinct; it's the quiet ones that have closed up clearances that you need to catch.
Also check oil feed from the 4 gallery drillings on the inlet manifold side: warm up the engine, remove cam cover; refit plug leads & re-start engine; check for equal jets from all 4 drillings then switch off engine before too much oil gets spattered everywhere. Blocked drillings are rare these days though due to better anti-sludge properties of engine oils than 30-odd years ago.
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Mon 15 Feb 2010 @ 09:15
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Anon
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Just out of interest why are there no seals on the exhaust stems?
Cheers...
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Thu 25 Feb 2010 @ 13:38
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Anon
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They're not needed. Valve stem seals are to prevent oil being drawn down the valve stems when the throttle butterfly is closed: the depression ('vacuum') created in the inlet manifold that can suck excess oil past valve stems only affects the inlet valves.
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Thu 25 Feb 2010 @ 20:25
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Anon
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Fitting cylinder head
(I'm updating this blog while I'm away from home so I'll edit it & add some useful numbers when I get back.)
Bottom end pretty much as I left in when it was fitted (see part 1 thread), all bare metal surfaces well oiled to deter corrosion but now with the distributor fitted any old how -
This is to prime the oil pump, by winding the auxiliary shaft round until oil comes out of the camshaft oil feed. Whether a standard filter (Fram PH966B) or high capacity one (Fram PH977A) is fitted, filling the filter with oil before spinning it on will save a lot of turning of the auxiliary shaft.
Incidentally, when I started using high-capacity filters on slant engines I discovered on my own CF that the oil ran cooler as well as stayed cleaner for longer. I think this is because the filter sits smack bang in the middle of the air stream through the ventilation slot below the bumper, an unintended consequence that turned out good for me because my 350s worked hard for their keep.
With excess oil mopped out and the top face of the cylinder block cleaned off & dry the locating dowels and camshaft oil feed restrictor (clean!) can be fitted -
Next, the cylinder head gasket and restrictor O-ring seal -
The Gaskets Direct approach of using sealer around the gasket is interesting; GM & Payen gaskets rely on the gasket material itself sealing to the cylinder head & I've had no experience of problems with either so this looks like belt and braces & could deter leakage when the O-ring seal dies a death eventually.
With all pistons still about half way down their bores & pistons 1 & 4 on the up-stroke, plonk the cylinder head back on, fit all 10 bolts -
then tighten evenly, from centre outwards.
Inlet manifold studs are different lengths: longest goes at the front, then the next longest, then the rest all the same length. Some engines have another stud right at the back, the same length as the other 2 to the rear.
Manifolds fitted along with the fuel pump -
The fuel pump can be primed before fitting it by connecting the inlet to the tank pipe & working the pump lever; with a length of hose on the outlet the first spill of petrol with any crap that it flushes out can be caught in a container then discarded.
Next, the water pump by-pass pipe to the rear of the inlet manifold (fit both unions loosely before tightening either), camshaft and timing belt -
All 10 camshaft housing bolts need to be tightened evenly from the centre outwards and in stages so that the housing pulls down evenly.
On this engine I've chosen to use the paper gasket with Loctite 5922 rosin-based glue because I've discovered that it works rather well; if it fails then plan B is to delete the gasket & use Loctite black RTV silicone instead.
The pulleys for the camshaft & auxiliary shaft may have 2 timing marks on each, a round mark & a vee mark on opposite sides. The auxiliary shaft pulley is fitted with the vee mark facing outwards & the camshaft pulley is fitted with the round mark facing outwards.
Turning the camshaft first to align the 2 pulley marks with a straight edge (or length of string pulled tight - works for me) before rotating the crankshaft to align the crankshaft belt pulley key with the TDC (top dead centre) mark on the face of the cylinder block will avoid valve contact with pistons provided the crankshaft hasn't been rotated from pistons 1 & 2 rising before fitting the cylinder head.
The elbow connected to the water pump outlet should have gone on before the timing belt though. Oh what a silly sod! However, with the tensioner slackened off it can be eased in once the crankshaft is rotated backwards enough to slacken the belt that side.
The external TORX head tensioner adjuster bolt is worth keeping: the bolt is tougher than an ordinary 5/16" UNC hexagon head bolt & can be wound up tighter for it.
First check/adjustment of valve clearances is done now, after which camshaft cover can be fitted, then the distributor with the crankshaft at 9 degree before TDC (timing mark on cam belt cover) and the auxiliary shaft & camshaft pulley marks re-aligned -
Distributor rotor position faces the camshaft when everything is aligned right & the corresponding terminal on the cap is for No 1 cylinder (front), then 3-4-2 anti-clockwise. Pretty much everything else (carburettor etc.) was fitted before the cam belt cover.
Before fitting the cam belt cover it's important to make sure that the 3 washers (1, 2 ,3 above) on the studs for the cover are BIG ones to prevent the plastic of the cover from distorting too much around the studs when the nuts are fitted & tightened. The cover then will be easier to remove & refit later.
Cam belt cover fitted -
View from the back -
Red stuff on the cam cover gasket was Loctite spray adhesive to stick the gasket to the cover but the temperature was way too cold for it (& my fingers!) to work & the gasket fell off when the cover was removed for final valve clearances adjustment. Carpet glue did the trick in the end once the gasket & cover had a clean.
The engine fired up & ran at this stage so the ignition timing got done while things were easy to see with the radiator out of the way.
That's it for the cylinder head apart from final adjustments once the cooling system is re-instated.
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Sat 27 Feb 2010 @ 21:09
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Anon
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Man alive Phil!!!!! I am speechless 
Congratulations and thankyou - these blogs are priceless.[bow] 
Cant wait to get on with restoring the van.....need to move house first though.....to be closer to the workshop 
All planned for end of April...
Carl
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Sat 27 Feb 2010 @ 22:49
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