| I was thinking of having the Cylinder head(?) skimmed to increase compression of the engine and improve performance. How much would people who have had this work done advise taking off? (11/99) |
| While the head is off I'd certainly consider replacing the timing belt, assuming it's getting on a bit. Regards compression, at 9.4:1 the 1.6 is pretty high anyway. Do you really want it higher? (11/99) |
| Once you get above 9.5 you need to start looking at higher octane ratings, 98+, and/or detonation sensors. Probaly better off doing things like porting, polishing, and volume balancing, maybe bigger valves. (11/99) |
| How long does it take to remove a Cylinder head on an mx5? The garage I've taken it too says it will take them 8 hours to take it off and remove it. I thought it was quicker job than this, especially for a mechanic. How much would you expect a garage to charge you for removing it? My cam belt was changed 9k miles ago. Do I need to have this replaced? (11/99) |
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Sounds like a long time to me - does that include replacement as well? I would say that you can get it off in about 2-3 hours if you know what you're doing, and reassemble in about 4-5 hours. Cost would depend on local labour rates - possibly 30 per hour? but plus or minus quite a lot. Have you checked that your plug hole really is stripped? I'd have thought it more likely that the plug has just unscrewed. ALWAYS use a torque wrench, always lubricate the threads with a trace of copper grease and torque to 15 ft.lbs. Can you screw a new plug into the hole most of the way by hand, and will it tighten to that torque in about 1/3 turn? If so, I would have thought you'd be OK. If you really must remove it - I was looking at Randy Stockers site - he recommends skimming 0.010"http://members.aol.com/solomiata//CheapHP.html off the head and says it will give about 4 bhp. But then you'll need a head rebuild, and that will cost 200+parts. See If your cambelt is OK it can just be put back - but make sure it's running in the same direction (your chalk mark might help) (11/99) |
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What do garages charge in hrs for a timing belt removal?? Take that time and add 1.5hrs max to remove the head. Remember that they have to remove your timing belt without damaging it unless you're prepared to give them a new one. I did a 1600 MX5 engine swap in a mate's garage and it took us 8-9 hrs for the swap. This included swapping over the ancillaries. We had a compressor and impact wrench so it did help with the time. Your garage should have a impact wrench anyway. BTW this engine swap was done on a UK spec MX5. It had a timing belt changed by a Mazda dealer in N. London 10Kmiles before. Reason for changing the engine was the dreaded crankshaft bolt!!! Are you sure that they are not quoting for the re-fitting?? (11/99) |
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.... come on .. I pulled out my engine in about 5 hours .. on my own ... with a turbo to pull out first. 3 hours to remove oh .. possible light ... my brother had the poping spark plug trick ..in his case the centre electrode blew out of the Champion plug and so it was just a case of undoing the outer steel bit. .. and as for raising the compression ratio by skimming .. yes it has been done .. 0.040" was one figure I saw but you may need to do a few things to gain access to the improved power .. retard timing for pinking .. buy vernier cams to reset the timing ... so useful if you want to go that way . but also may make the valves hit pistons if a cambelt breaks .. .. and 9k miles on a timing belt .. keep it as they will spend another 40 mins getting down to the front pulley etc to change it .. unless you go the for the skim.. (11/99) |
| Well after the Garage yesterday quoting anything upto 300 quid to fix the stripped spark plug chamber which would involve removal of cylinder head...turns out the garage didnt nead to remove the head and only charged me, 70 GBP!! They said the 300 pounds was a 'worse case scenario'!(11/99) |