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Mineral v synthetic oil

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  • gazman
    gazman
    2 years ago
    I know it’s a much discussed issue and I’ve checked out some of the old posts on oils for your twin cam but I’m still in doubt. I done 180000km on my stock tc 88 and always ran HD 20/50 mineral in the engine and formula+ in the trans and chain case. I had the motor rebuilt recently and it’s now a 103 and travelled 20000 km already. I am still using HD 360 20/50 in the engine and it’s ok but this engine uses more oil than my old 88. The bike runs well and pulls well using se 211 cams and wiseco 9.6 flattops. I am considering changing over to synthetic oil as I’ve heard it may not break down as quick as the mineral oil and maybe my level may stay higher on the dipper for longer. Any thought appreciated. Btw I change eng and primary oil every 4 to 5 thousand km + filter every time.
  • leachy
    leachy
    2 years ago
    Hi Gazman,

    I dont think it will reduce your oil consumption that is generally caused by other things. The benefit is that the oil will not break down as quickly. So when the temperature of the engine increases like it does here in summer the oil essentially wont fall apart, it will protect the internals better and hence reduce wear.

    If you change you oil frequently and the engine doesn't get really hot all the time you probably wont see the difference.

    Regards
    Leachy
  • gazman
    gazman
    2 years ago
    Hi Leachy yea thanks for the info and I suspect you are correct about other things causing the consumption issue. I will stick with what I’ve been using I think as I change at 4 thou km now. If it gets worse over time I’ll put a new set of rings in. Cheers.
  • steelo
    steelo
    2 years ago
    Fwiw g. On 03 1450 Softtail with 122k, I do an oil change every 5k, full service every 10k. 
    Easy to remember. 
  • gazman
    gazman
    2 years ago
    Yea Steelo I used to do that every 5000 k as well but this motors using most of the spare quart left over from the gallon container by 4000k especially after it starts to break down a bit after 2000k onwards.
  • tussuck
    tussuck
    2 years ago
    Not another fucking oil thread!.....  
  • steelo
    steelo
    2 years ago
    Sorry for buying in T. By the sounds of it, the oil isn't the problem for GM but has indicated to him that something is wrong. He's got a good service interval
  • paulybronco
    paulybronco
    2 years ago
    Quoting gazman on 27 Jan 2022 12:18 AM

    I know it’s a much discussed issue and I’ve checked out some of the old posts on oils for your twin cam but I’m still in doubt. I done 180000km on my stock tc 88 and always ran HD 20/50 mineral in the engine and formula+ in the trans and chain case. I had the motor rebuilt recently and it’s now a 103 and travelled 20000 km already. I am still using HD 360 20/50 in the engine and it’s ok but this engine uses more oil than my old 88. The bike runs well and pulls well using se 211 cams and wiseco 9.6 flattops. I am considering changing over to synthetic oil as I’ve heard it may not break down as quick as the mineral oil and maybe my level may stay higher on the dipper for longer. Any thought appreciated. Btw I change eng and primary oil every 4 to 5 thousand km + filter every time.

    Did you do the build or a shop...
  • beaglebasher
    beaglebasher
    2 years ago
    Quoting gazman on 27 Jan 2022 12:18 AM

    I know it’s a much discussed issue and I’ve checked out some of the old posts on oils for your twin cam but I’m still in doubt. I done 180000km on my stock tc 88 and always ran HD 20/50 mineral in the engine and formula+ in the trans and chain case. I had the motor rebuilt recently and it’s now a 103 and travelled 20000 km already. I am still using HD 360 20/50 in the engine and it’s ok but this engine uses more oil than my old 88. The bike runs well and pulls well using se 211 cams and wiseco 9.6 flattops. I am considering changing over to synthetic oil as I’ve heard it may not break down as quick as the mineral oil and maybe my level may stay higher on the dipper for longer. Any thought appreciated. Btw I change eng and primary oil every 4 to 5 thousand km + filter every time.

    I put full synthetic oil in my bike only because I am a lazy bastard.
    It gets changed every second year or 10K . 
    If youre losing oil you need to find out where youre losing it from.
  • gazman
    gazman
    2 years ago
    Quoting gazman on 27 Jan 2022 12:18 AM

    I know it’s a much discussed issue and I’ve checked out some of the old posts on oils for your twin cam but I’m still in doubt. I done 180000km on my stock tc 88 and always ran HD 20/50 mineral in the engine and formula+ in the trans and chain case. I had the motor rebuilt recently and it’s now a 103 and travelled 20000 km already. I am still using HD 360 20/50 in the engine and it’s ok but this engine uses more oil than my old 88. The bike runs well and pulls well using se 211 cams and wiseco 9.6 flattops. I am considering changing over to synthetic oil as I’ve heard it may not break down as quick as the mineral oil and maybe my level may stay higher on the dipper for longer. Any thought appreciated. Btw I change eng and primary oil every 4 to 5 thousand km + filter every time.

    Quoting paulybronco on 27 Jan 2022 12:22 PM

    Did you do the build or a shop...

    A shop did the build and I took it back at 3000 km because of the consumption issue. He pulled it down and put it back together but I don’t reckon he changed the rings as he said it all looked good. The bike runs well so I don’t think I’ll worry about it for now. I’ll stick with the mineral oil. 
  • FBUser214
    FBUser214
    2 years ago
    Do a compression test and a leak-down test. If you don't have the gear , find somebody that does.
  • fatbat
    fatbat
    2 years ago
    I’m with magnum and the others. I’d test it and independent of the shop. If/when wiser as to the cause, take it back asap. Oil type won’t matter much if it’s using oil 

    On a side issue but who supplied the parts, you or the builder? The last thing you want is the builder blaming the parts you supplied. If you’re doing an exxy and labour intensive build with somebody you don’t trust 100% (I barely trust anybody that much), I prefer the builder to supply the parts. Less complicated if things go wrong. I had a shop do my last twin cam 107 engine build and bloke insisted on supplying the parts too for the same reason. He was an accredited s&s dealer so I knew he’d have s&s support behind him too. He wasn’t a machinist but took parts to an engine machine shop to measure, check, trim etc too. Too many things can go wrong even with reputable parts 
  • gazman
    gazman
    2 years ago
    Hi Fatbat the shop supplied all the parts. He is an independent operator with a pretty good reputation and been building custom bikes and putting together motors for over 20 years. It’s possible the oil issue may be piston ring related. I asked for forged flattops when he was going to use cast 103 Harley pistons. However because of a lack of availability at the time I ended up with wiseco pistons and rings. Now I’ve heard varying reports as to their quality these days so maybe it is the ring quality. Also when I took it back the first time complaining I sort of got the feeling he thought he may have stuffed up in the warming cycle on his dyno so he said he pulled it apart and it looked fine, but he said he ran a coarse hone through the bores and then repeated the bedding in process. Well yes it definitely cut down the consumption but it still uses about 3/4 of a quart in 4000 km. I think I can live with that because the motor gos really well. Comp test showed 180 front 175 rear so the issue would be rear cylinder I reckon.Head was completely recoed so leak down would be unlikely. Also back plug shows some light brown specks on insulator which could be oil.
  • Stewy
    Stewy
    2 years ago
    If it is using 3/4 of a quart= 709ml in 4000 km. That is alot of oil. You should be able to see it all over the back wheel from the leak or it will be blowing lots of blue smoke out the exhaust. Very visible. Have you checked your primary oil level, Dynas can transfer oil if main crankshaft seal is fucked
  • gazman
    gazman
    2 years ago
    Well I can’t see any smoke and the plugs aren’t oily and I haven’t noticed the primary level going up either. Blowby has decreased over time as well with little coming through the breather either. I do always check my oil level cold on the jiffy on a flat surface and try to keep it at the half way mark cold. The owners manual says to add to the halfway mark cold only when approaching the add quart mark. Maybe I’m adding to much in between.
  • FBUser214
    FBUser214
    2 years ago
    Here is a guy who had a near new CVO Fatbob which was losing oil at about the same rate as yours. He got it fixed after about 6 years.
    I doubt you have ACRs in yours, but there are some useful suggestions there you could have a think about.
  • gazman
    gazman
    2 years ago
    Thanks mate I read that thread on that forum and found it interesting. But excuse my ignorance but I don’t know what ACR,s are ?
  • FBUser214
    FBUser214
    2 years ago
    Quoting gazman on 29 Jan 2022 08:54 AM

    Thanks mate I read that thread on that forum and found it interesting. But excuse my ignorance but I don’t know what ACR,s are ?


    Automatic Compression Releases
    The CVOs run them because they have stock cams that create high compression and the ACRs bleed of that compression to assist with starting.
    ACRs can be used with other high compression fuel injection builds because they can be easily incorporated in the wiring harness.
    Older bikes and some EFI use manual compression releases.
    They need to be taken out of the equation when checking compression.
  • gazman
    gazman
    2 years ago
    Ok thanks for clearing that up.
  • Retroman
    Retroman
    2 years ago
    Just a wee bit of clarification, all 103 motors since 2011 have had ACR ( Auto compression release valves) as stock OEM fit.

    The 103 was originally the "CVO" motor, since 2007 to 2017 the CVO motor was 110".

    So often here in Perth at least the first reflash of the ECM for stage1/2/3 etc often the ACR was "toggled off" in the calibration.

    And that was usually from the dealer workshop !

    A drift off topic I know , but you have to check in the tuning constants if the "ACR is on" for a 103 motor.

    (I used to see it all the time and often diagnosed it at startup)

    On the oil topic , I have used synthetic oil continuously in all my own Harleys, and most all that I service , since 1995.

    Brand loyalty has changed over the years (principally due to availability and price). Mobil 1 V twin / Redline etc.

    These last few years I have been a Penrite man , that's what I keep on the shelf now. Bought in bulk at Supercheap 25% off days !


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