V8 top end & timing chest rebuild.

[yammy1300]

Yey, nice one Rik, now you can come and get Goldie running as sweet as yours

[1130cc]

Nice write up, as usual.

Richening up, is it screw out?
Saves me looking it up.

[VmaxRik]

In for rich...out for weak.


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[1130cc]

I checked my carb richness on the weekend, as I had a sneaking thought that I read the initial set up was 4.5 turns.

Wound them in ( a lot) and then back out 2.5.
OMG! What a difference. I had had a lazy rev up, but is much faster/smoother now.

Gonna start the setup from scratch.

So, is TDC measuerd on the up, if that makes sense, or does it not really matter.
What would recommend as the timing degrees. I have a protractor

I finally remembered what was missing from you're build details........
Checking the gap on the lifters. I thought you would have done it as you changed the heads

[yammy1300]

In for rich...out for weak.


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Thats what I did to Goldie, amazing difference, 1/4 turn in, job done

[VmaxRik]

1130cc.....Pleased you got some use out of the carb set up.


TDC is found by sticking a DTI down no'1 plughole assuming the heads are on, and slowly rotating the engine back and forth until the highest travel of the piston is achieved. The TDC blade on the front cover that points at the TDC mark on the crankshaft damper is adjustable, just loosen the two retaining bolts and line the blade up with the TDC mark on the damper....job done. Using normal unleaded fuel the static timing on the distributor should be set at 8-10 deg before top dead centre.

Tappet preload then...


"The following information assumes that the following components are in good condition - rockers, pushrods, valve guides and valve stems. a clearance of .020" to a maximum of 0.60" must exist between the spring loaded pushrod seat in the top of the lifter, and the underside of the retaining circlip. This check should be made with the valve gear fully assembled, and the lifter empty of oil, positioned on the lowest point, on the back of the camshaft. The simplest way to measure the gap is by using round wire. Use a piece .020" for the low clearance check, and a piece of .060" for the high clearance check. Check all 16 lifters individually."


The important piece in the above is "the lifter empty of oil"...mine weren't. So you have to go back the ancient original Rover manual, which never ever mentions it anyway to find out how they were originally put together.....Mine runs strong now with a near perfect tickover, hardly any crankcase compression and no nasty petrol smells coming out of the rocker boxes which would be a dead give away if the valves hadn't seated properly.










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[Doc.]

. . . sticking a DTI down no'1 plughole assuming the heads are on, and slowly rotating the engine back and forth until the highest travel of the piston is achieved . . .

I always use the 'dead-stop' method, far more accurate due to the 'dead' area around TDC (the few degrees of movement at the Crank where there's no discernable movement of the piston).

Gut an old Spark plug, and epoxy/weld a piece of rod/bar into it, so that when screwed into the plug-hole, it stops the piston 1/4" or so before TDC.
Turn the Engine slowly until it stops, mark the degree wheel (or just note the position), then turn the Engine backwards until it stops again, mark/note as before.
'True' TDC is the point exactly in the middle of the two positions.

Not so critical on a big four-stroke I'll admit, but when you've grown up on a diet of two-strokes, you like to get it spot-on . . .

[VmaxRik]

Good info Doc...and well useful.

The main problem with the Rover V8 is everything's built there or there abouts. No cam chain tensioner so the valve timings a bit all over the place, especially on tickover. The factory crank dampers can be stamped as much as 20deg out at TDC...so most people ignore what's actually on it and make their own marks. The camshafts are normally only fit for the bin after as little as 30K.....etc etc.

I still love the old Hectors though.


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[1130cc]

Doc hit on what I was thinking, which why I asked if it was set on the up or down stroke.
We now have an even more accurate way to measure :=}

So, I will be playing with TipEx this weekend.

[VmaxRik]

I quietly took it out for a bit of a thrash the other day, oh dear.

The race heads and mega thin head gaskets aren't doing much for the lumps crack case compression. Gawd only knows what CR it's running now, but it's a LOT more than 10.5-1 the pistons and rings are rated at. So it now looks like a steam train out of the breather on the oil catch tank when I'm ragging it....this isn't a good thing.

So, it's time to whip the heads back off and fit composite gaskets again to lower the CR back down to stop the ring blow past causing a gale in the crank case.

Shame really as it goes like scary stink at the mo'....but for how long?? Thats one very expensive question I'm not willing to ask of it. It's only £40 or so for a top end composite gasket set and three or four hours work to fit them. So, as their 1mm thicker that should calm things back down and let the poor old rings do what they where designed to do....keep all the compression in the combustion chamber, rather than letting it blow past them.

Onwards and forever upwards....after I've spent a bundle of money getting the Merc roof ECU repaired.


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