I have finished the race season for 2011 in my mk1 8v. Now I was to check the engine over for the winter and see how things look. My problem is I don't know what I am looking for! I am happy to lift the engine out, and I am going to compression test it before I do this. After that though, what should I be measuring/checking? I want to replace oil seals, as it has a leak at both ends, outout shaft and one of the belt end seals. Someone suggested I look at the Shell Bearings too, as it regularly revs to 7k +. I want to remove the sump anyway and see what spec if possible the crank is and the top end also for the cam, as both are unknown. The head was built by Dave Crissle (AKA man in the shed?), with solid lifters and buckets etc, Don't really want to remove the head unless I need to?? Any tips and suggestions please, sounds terrible I know but I still get confused as to what engine it is, pb/ex etc! Its running twin 45's and I will also check the intake for porting gains to be made etc. The dizzy was also confusing too as it has no vacuum, and the 3 pin hall plug is it? Suggestions of what this is from would be good, as it was jumping on timing slightly when last Rolling road session or so I was told... THanks Alex
It would be a good idea to do an accurate compression check, both cold and hot. And an oil pressure check with an accurate gauge too. Tappet clearances would be good to have. These would give baseline readings to have "in the bag" then any further tests could refer back to these readings. If the rev limit is 7k then this is not particularly high. If decent oils have been used and there have been no incidents of over-rev or over-heating then it could still be a healthy engine with no need for a strip down. Possibly a trip to a reputable and knowledgeable rolling road may show up areas that need looked at to improve performance. Small adjustments can make big changes to output. Once the engine is removed then you only have the visual inspection of the components. That is useful for sure, but it may not show how they all interact with one another when the engine is running. Pulling the engine down is a big step that will have substantial costs with the various procedures involved, and the gasket costs in the rebuild soon add up too. The leaking oil seals are easily changed without major engine stripping work.
Thanks Danster. I will do the compression tests and see what seals I can replace in situ. I do want to take cam cover and sump off to change gaskets and see what I find regards to spec in there. No its only over reved a few times maybe to 8k. I run Fuch race oil in the 10-50 and it never over heats oil or water, or smokes. It does use oil but not excessive I would say, and half down to the seal weaps. I will run the car along to SRR to give me a base for any winter tuning and fettling with JMR or who ever it gets along to. I know the head should be ok as it was only built last winter.
What cam is in it? With a lumpy cam you might see inconsistent timing at tickover. I'd think it's really a question of trial and error to set hit up. I'm not really surprised that the vac advance has been removed on a race engine - should help to avoid pinking at light throttle, and light-throttle flexibility isn't really a big issue on a race motor, as I'm sure you're aware Are you running standard solid tappets or under-bucket shims? 8k on a lairy cam would be a bit risky with standard ones. If I was you I'd do a visual inspection on the top end to check for any signs of wear, plus when you take the bearings out to check them, measure the crank journals to check they're still round (they can go a bit oval in hard use). I wouldn't change bearings unless you really need to, as it'll tighten the engine up. I'd also be looking to see what type of fasteners are in there. 7k ish you should be OK with stock fasteners, but ARP ones would be safer, if budget allows.
Not sure on the cam, a Shrick was mentioned. But I will be checking it this weekend. Doesn't have a lump idle. It does have under bucket shims though. Again no sure on fasteners. All a bit of a grey area the rebuilt engine. Will report back on weekend findings.
Schricks have the part number etched on the gearbox end face of the cam... can be a bit faint, but usually readable. The engine will be less of a grey area by the time winter is over!
Well I did a compression test. Warm engine, carb throttle fully open, plugs out. All cylinders were 80 psi, which seems low to me?? It is only an ebay special cheapo tester... Will double check oil but fairly sure it reads in lb and is around 90. Never gets too hot either 80 c at most and water around the same. All gauges are SPA gauges so decent quality.
That is a low reading. It could be a poor quality meter. Was the engine turning over quickly? The fact they are all the same is some good news. I think it may be best to try and test again with another compression meter, or try the current meter on a known car with good compression to compare gauge readings.
Ah yeah good idea I will check the meter on the other car. It was turning over as well as it does normally, maybe a little low but the battery had been standing I gave it a jump and let it warm up then tried it. Being even across the range is what I thought more important. THe fittings were not amazing quality and only a rubber o ring as a seal. Will also see if I can borrow another test set.
Would the engine need to be even hotter, it was around 50c oil and water. They are wossner forged pistons, and someone said they need to get really hot? ?
Did you remember to wedge the throttle wide open for the compression test? It can't get much air to compress if the throttle is shut.
Sounds like a dud tester then. If you really had 80 psi on all cylinders, I'd be surprised if it ran, never mind pulled the car along. At least the reading was consistent though! I've got a 20 quid Gunson's tester, which seems to give sensible and consistent readings. It reads on the high side, if anything, but that doesn't really matter if it's consistent. You're welcome to pop over and use it, but by the time you've paid petrol from Watford (I think that's where you are...) , you'd probably be as well going to Halfords and buying a new one.
