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'IF IN DOUBT, OUT!' - with parts, we feel that you should not use anything you are not happy with - the majority of Rover parts are very reasonable in price, when compared to other manufacturers.
Racing / Rallying (fully synthetic)
Mobil 1 Motorsport 15/50
ELF F1 15/50
Road (Semi / Fully synthetic)
10/40
Champion RC6YCC up to 11.5:1
We recommend Magnecor HT leads.
82 degree 01GTS282
74 degree GTS1102
Headbolts we only recommend using OE bolts, and don’t recommend using any aftermarket type headbolts as the ones we have tried don’t stretch the same as OE bolts. Don’t reuse them - for the cost its not worth it!
Make sure when fitting the flywheel, that you don’t go round and tighten each bolt individually (tighten an opposing pair of slave bolts then work round opposing pairs with new bolts) as otherwise the adhesive will find its way between the flywheel and crankshaft, eventually leading to the bolts coming undone and the flywheel coming off.
These have been known to come off, worth putting a couple of blobs of weld on to retain the ringear.
We use and recommend the earlier manual VVC timing belt which is 4 mm wider than the standard MPI belt.
We have found it a wise precaution to convert later engines to the earlier Manual belt tensioner (omitting the spring, as this can detach and damage the belt).
It is recommended that the belt is checked and replaced frequently, as the belts have been known to come off the pulleys and find their way behind the crank pulley and take the cambelt off or make it slip, which is usually very terminal.
Alloy crank shaft pulley, avaliable from Hellier Performance.
This item needs to be checked for a good fit on the nose of the crankshaft, as they have been known to wear on the D drive leading to failure. (very cheap to replace, not worth the risk.)
Ensure that when changing the cylinder head or head gasket each liner has the correct standoff as otherwise you will have wasted your time and the head gasket will still blow (note this is very important but lots of people still do it everytime).
Grinding Tappet Shims.
Converting hydraulic followers to solid, an acceptable way of doing this is by replacing the hydraulic valve with a shim, this is satisfactory for a road / trackday engine, but if consistently using high revs, with race profile cams the followers can fail.
The standard valves are acceptable for a production engine, but tend to wear rather fast when used over 7800 rpm. So we would recommend using the VHPD motorsport valve, or a race type 214/N plasma nitride valve for race use.
The standard valve stem to guide clearance is a little on the big side, and the length of the guides at 30mm is very short, so guide wear is accelerated with the use of high lift cams. We are now manufacturing longer guides in Colsibro which are fitted so they protrude through the port in the standard position, the extra length being accommodated above the spring seat, we also tighten the stem to guide clearance which greatly helps with wear.
We have found that with standard valve sizes the standard head can be modified to achieve around 100 cfm, which in theory is good for around 170- 180 bhp.
Above this its not really economical to modify as a massive amount of material has to be removed from the ports to get bigger valves to work.
For this reason we prefer to use the MS2 / VVC casting. With the standard valve sizes this head can be modified to flow around 130 cfm easily and 140 cfm with a bit more work.
We are now up around 151 cfm on the inlet with more to come.
For more detailed flow figures see here.
K16 .007” per cc
MS2 / VVC .009” per cc
We recommend the following system diameters for N/A engines.
Up to 160 bhp 2.25”
160-200 bhp 2.375”
Over 200 bhp 2.5”
We would not advise using the standard pistons above 160bhp as the ring lands will eventually fail. The VVC engine has a slightly uprated piston, with the ring pack located slightly lower (retaining more strength in the ring land).
Skirt wear on standard pistons can be a problem if high revs are used.We have seen standard engines that have done 18000km with a piston to bore clearance of .005” (standard limit .0008-.0012” ). You can usually hear the piston slap.
The Omega full skirt piston is a very good piston and will last up to around 30,000 km With occasional track use, dependant upon revs used.
Slipper pistons are for race use only and tend to last around 2000-3000 km dependent upon revs used.
The standard 1.8 conrods seem to be ok for engines up to 180bhp. There is a standard type forged conrod available, or the EN24V machined all over type for higher power / race engines. These are widely available from a number of manufacturers.
The standard 1.4 / 1.6 conrods are ok up to 160bhp, they will fail above this level.
We don't recommend running the standard crankshaft for any racing / rallying where the vehicle used is a saloon car. (as the standard crankshaft has a weak spot just in front of number five main bearing) the problem seems to be with the heavier cars doing standing starts. This eventually fatigues this area leading to breakage.
The options are a heat treated crankshaft which is cast in a better material and then heat treated, or a EN40B crank.
We balance our crankshaft assemblies on a Borgo digital crank balancing machine.
They are balanced so that the machine reads zero on the finest most sensitive scale, we are very particular about our crank balancing.
Crankshaft failure.
All the crankshaft failures that we are aware of have been when NOT using the standard type crank damper, and revving the engine to over 8500 rpm.
This shows the a typical failure.
So we always advise using the damper and keeping the revs to 8500 rpm, (including downshifts). EN40B steel cranks were durability tested, as part of the VHPD development program, this testing was 120 hours of running from 7500- 8500 rpm, with damper fitted and with no failures.
Strengthened crank - note the web that crosses the recess, compared to the crank shown in the pictures above.
With the rear engined cars Elise, MGF oil surge doesn’t seem to be to much of a problem. (because of the engine installation).
But with the front engined cars MGZR etc it definitely is a big problem, we have heard of many surge related failures.
MGZR sump with our baffle in position.
We use our own design gated baffle assembly on Gravel / Tarmac Rally, and trackday engines were a dry sump system cannot be used.
Sump Baffle.
For Caterham fitting tips - see here.
A version suitable for the shallower sump found on Caterham's has now been developed, and is proving very popular as a sensible upgrade.
These have been known to blow out at high revs due to crankcase pressure, (quite common on various race engines).
Easily cured by ensuring engine is well vented and retaining the rear seal with 2 M3 cap heads.
The standard bearings are steel backed aluminum, and don’t lend themselves to heavy loads. As long as the engine has regular oil changes, yearly rebuilds and the revs used are sensible, we have found them not to be a problem. Lead copper (indium) bearings are now available, but they are 10 times the cost.
Through experience we have found that the standard fuel filter as fitted to MGF, Elise, MGZR models does not flow enough fuel for engines exceeding 200 bhp.
So we would advise using a higher flowing filter.
If you have a problem with a loss of power or your rebuilt engine doesn’t give the required power check the cat has not collapsed, or isn't blocked.
We recently had an Elise that would not start, removed the cat and it was completely blocked, cranked the engine and it started straight away.
The latest design 200 cells per inch motorsport cats are proven to gain approx 2-4 bhp depending on application, and are worthwhile using.
In our experience ratios of 11-11.5:1 seem to be the best compromise, with standard pump fuels. We have run up to 13:1 but have found that there is not much to be gained even with race fuels. Above 11.5:1 there is a increased risk of liner failure if using cast iron liners, whether interference fit or standard.
Standard MPI approx rate
Standard VVC approx rate (weaker than standard MPI springs)
VHPD good uprated single spring we have found these to be approx 5-8 % heavier spring rate than standard, for lifts upto 10.5mm approx these springs are from a prototype Diesel engine.
Alternator heat shield as used on the MG ZR
It is important to protect the alternator when using a tubular manifold, especially on later Euro 3 engines an unprotected Alternator will be fried in no time, and a new alternator is around £227.00
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