Converting from leaded petrol - super unleaded
+ Reply to Thread
Results 1 to 19 of 19

Thread: Converting from leaded petrol - super unleaded

  1. #1
    MIGWeb User
    Join Date
    Mar 2002
    Location
    Hampshire - UK
    Posts
    2,469
    Drives
    C20LET Mk4 Astra

    Converting from leaded petrol - super unleaded

    Not on a vauxhall but a metro turbo.

    How can you tell if an engine has been converted to run on unleaded?
    Are there any tell tale signs to look for?

    Am I right to think that the head needs some 'work' to allow super unleaded, or is it more complex than that

    If the engine is still being run on leaded, how much would the relevant work cost to convert it to super?

    I know that the last time the car was regulary used was back in 2002, and has been treated to a dump valve and k&n filter, so I have a suspicion that if the previous owner/owners spent money on them bits, they may well have had it converted

    Lastly, what sort of damage could have been done if leaded petrol was used in attempt to get it started. lmao
    C20LET Mk4 Astra

    247.4 bhp @ 4160 rpm & 315Ibs @ 4030 rpm

  2. Remove Advertisements
    MigWeb.co.uk
    Advertisements

  3. #2
    Administrator
    Join Date
    Jun 2000
    Location
    Hampshire, UK
    Posts
    29,694
    Drives
    Family Car

    Re: Converting from leaded petrol - super unleaded

    yes the head needs work to make it properly runnable on unleaded, the head has seats carved into the head for the valves and the work involves cutting these out and putting valve seats that will not suffer from using unleaded fuel

    alternatively you could find an inline filter that adds tin i think to the fuel so that you fill up with unleaded but by the time it gets to the chamber its abck to leaded spec
    For issues using MIGWeb please use our helpdesk - do not PM me. Thanks

  4. #3
    MIGWeb User
    Join Date
    Jan 2002
    Location
    Bradford
    Posts
    6,763
    Drives
    a Crotch Rocket

    Re: Converting from leaded petrol - super unleaded

    Not 100% but i think some later ones were able to run on unleaded. If it can't it needs new valve seats fitting and cutting.

    Lastly, what sort of damage could have been done if leaded petrol was used in attempt to get it started
    I assume you mean unleaded? No damage at all. In fact you could run it on unleaded for many miles due to the protection built up on the seats due to useing leaded petrol for most of it's life.

  5. #4
    MIGWeb User
    Join Date
    Mar 2002
    Location
    Hampshire - UK
    Posts
    2,469
    Drives
    C20LET Mk4 Astra
    Thread Starter

    Re: Converting from leaded petrol - super unleaded

    Cheers for the info Tom...prefer to get it done properly.

    Do you know who did Jamies head work?
    C20LET Mk4 Astra

    247.4 bhp @ 4160 rpm & 315Ibs @ 4030 rpm

  6. #5
    MIGWeb User
    Join Date
    Mar 2002
    Location
    Hampshire - UK
    Posts
    2,469
    Drives
    C20LET Mk4 Astra
    Thread Starter

    Re: Converting from leaded petrol - super unleaded

    sid - I put in 5 of leaded into the tank, just to see if it kicked the car back into life.

    I may well drain it out, and replace with unleaded this weekend, see if that makes a difference.

    Its on an F reg if that helps in finding out what petrol it takes.
    C20LET Mk4 Astra

    247.4 bhp @ 4160 rpm & 315Ibs @ 4030 rpm

  7. #6
    Administrator
    Join Date
    Jun 2000
    Location
    Hampshire, UK
    Posts
    29,694
    Drives
    Family Car

    Re: Converting from leaded petrol - super unleaded

    i have a feeling either jamie did but it might have been gary poole

    thing is byron the old seats are actually part of the head not a removeable part and the old seats need cutting out for new seats to be fitted

    best pop out and by a copy of mini world or call someone like somerford min's and ask who they know can do it
    For issues using MIGWeb please use our helpdesk - do not PM me. Thanks

  8. #7
    Administrator
    Join Date
    Jun 2000
    Location
    Hampshire, UK
    Posts
    29,694
    Drives
    Family Car

    Re: Converting from leaded petrol - super unleaded

    Byron, best start it with leaded to be safe
    For issues using MIGWeb please use our helpdesk - do not PM me. Thanks

  9. #8
    MIGWeb User
    Join Date
    Mar 2002
    Location
    Hampshire - UK
    Posts
    2,469
    Drives
    C20LET Mk4 Astra
    Thread Starter

    Re: Converting from leaded petrol - super unleaded

    Cheers Tom, its appreciated! I may well see if Dan can pop over to see if he can work his magic on a metro.lol.

    I will be happy once its running, as after that, its going into a mini.

    Good point Tom, its already got some in the tank (what i added), so may well add some more, cos if it was that empty it may have sucked in all the terd at the base of the tank
    C20LET Mk4 Astra

    247.4 bhp @ 4160 rpm & 315Ibs @ 4030 rpm

  10. #9
    MIGWeb User
    Join Date
    Jan 2001
    Location
    Northeast Kent
    Posts
    30,548
    Drives

    Re: Converting from leaded petrol - super unleaded

    Quote Originally Posted by Tom Williams
    thing is byron the old seats are actually part of the head not a removeable part and the old seats need cutting out for new seats to be fitted
    naaa valve seats are inserts. not removable in the nut and bolt sense, but its not part of the head.

  11. #10
    MIGWeb User
    Join Date
    Mar 2002
    Location
    Hampshire - UK
    Posts
    2,469
    Drives
    C20LET Mk4 Astra
    Thread Starter

    Re: Converting from leaded petrol - super unleaded

    so it could be dismatled and fettled...may employ the help of mr fisher.
    C20LET Mk4 Astra

    247.4 bhp @ 4160 rpm & 315Ibs @ 4030 rpm

  12. #11
    MIGWeb User
    Join Date
    Jan 2001
    Location
    Northeast Kent
    Posts
    30,548
    Drives

    Re: Converting from leaded petrol - super unleaded

    its not a DIY job. head specialist or machine shop only.

  13. #12
    Administrator
    Join Date
    Jun 2000
    Location
    Hampshire, UK
    Posts
    29,694
    Drives
    Family Car

    Re: Converting from leaded petrol - super unleaded

    as far as i was aware odders due to the design of the head, they were actually part of the original head but if diff then cool, but as odders says its no DIY job
    For issues using MIGWeb please use our helpdesk - do not PM me. Thanks

  14. #13
    MIGWeb User
    Join Date
    Mar 2002
    Location
    Hampshire - UK
    Posts
    2,469
    Drives
    C20LET Mk4 Astra
    Thread Starter

    Re: Converting from leaded petrol - super unleaded

    scrap that then, may see who jamie has used recently then, as they were pretty reasonable price wise.

    The car may well be already converted, fingers crossed. If the head was whipped off, could it be identified as being 'converted'?
    C20LET Mk4 Astra

    247.4 bhp @ 4160 rpm & 315Ibs @ 4030 rpm

  15. #14
    MIGWeb User
    Join Date
    Jan 2002
    Location
    Bradford
    Posts
    6,763
    Drives
    a Crotch Rocket

    Re: Converting from leaded petrol - super unleaded

    I suppose you could hardness test the seats, that will identify the material or you might be able to tell by colour

    I'd find one of the mini forums and ask. They'll be more gen'd up on it.

  16. #15
    MIGWeb User
    Join Date
    Oct 2001
    Location
    Herts
    Posts
    5,972
    Drives
    Grale, Mustang, 535i

    Re: Converting from leaded petrol - super unleaded

    I was once told that you may as well just run on unleaded. Most engines will never suffer a problem, and the only problem if it does is it will wear the valve seats - which are what you replace in an unleaded conversion. You may as well wait - if you get a problem then you get the work done that you would do anyway. If you don't have a problem then you've saved youself a couple of hundered quid!

    Mike

  17. #16
    MIGWeb User
    Join Date
    Mar 2002
    Location
    Hampshire - UK
    Posts
    2,469
    Drives
    C20LET Mk4 Astra
    Thread Starter

    Re: Converting from leaded petrol - super unleaded

    Yep, cheers mike. After speaking with a few of the technical lads at work (fleet car supplier) they all said just run it on unleaded, and forget about it.
    Even the 5 worth of leaded in the tank wont affect the engine in any adverse way.

    One of the fellas has a ford zephyr which he has used unleaded for 9 years with no problem.

    Im going to fill her up on saturday morning with unleaded and see what happens.

    Thanks for all the replys though
    C20LET Mk4 Astra

    247.4 bhp @ 4160 rpm & 315Ibs @ 4030 rpm

  18. #17
    MIGWeb User
    Join Date
    Jan 2001
    Location
    Northeast Kent
    Posts
    30,548
    Drives

    Re: Converting from leaded petrol - super unleaded

    i read a site yesterday that the seats could be safe for 10-15 thousand miles after stopping the use of leaded petrol, as sid16v said. naturally that means from years of leaded use before hand, not 5 quids worth.

    the seats degrade due to the soft metal being hammered by the stainless steel valves, in some cases almost welding the two together. its the lead in the 4 star that prevent this.

  19. #18
    MIGWeb User
    Join Date
    Jul 2000
    Posts
    14,521
    Drives

    Re: Converting from leaded petrol - super unleaded

    just run it on super unleaded. it will take 20,000 miles before you damage the head. If you're worried then stick in some additive
    BRB
    when the gagged ones are reinstated

  20. #19
    MIGWeb User
    Join Date
    Jul 2002
    Location
    Warwickshire
    Posts
    124
    Drives
    2.0lt 16v Mini

    Re: Converting from leaded petrol - super unleaded

    I had a mini head converted to unleaded seats for about 100. The original seats are part of the head and so inserts are required. Have a look on www.miniclassic.co.uk as i'm sure they have covered this subject previously to see if your head needs converting

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts