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luvemfast

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Posts posted by luvemfast

  1. Can you take the spark plug out.

    Turn the crank to get the piston BDC.

    Carefully put a bit of wire down, mark the length. (Take it out again)

    Turn to TDC.

    Put wire in, carefully. Re-measure.

    Would that give you the stroke at least?

  2. I'll be watching your progress as it's similar to my project.

    I'm going forged 89mm domed pistons with forged FJ20 rods using P90 head.

    Using 44PHH Mikuni's with TWM manifold and cold air box.

    Haven't done any block or crank work yet, just collecting for now.

    So hence. The interest in your build

  3. It was all said in the previous thread.

    Many times an engineering solution is applied that masks other true root causes...

     

    You want to add weight to mask a root cause, have at it. Who am I to stop you?

    Sorry Tony, but I've read through the other posts found here

     

    Doesn't really answer my questions.

    The answer

    "So much of this stuff is done 'because the other guy did it' and little thought is put toward the actual engineering basis for it!"

     

    I think you'll have to spell it out for me......... As I'm just a toolmaker.

    Engineering principles, yes.

    Race engine build knowledge, no (but working on it ;) ).

     

    Taken from an Aussie site, by a respected experienced builder.

    The rear main leak is from crank flex. The shaft is moving up and down this is the reason the seal is damaged.

    When replacing bearings on big hp l6 engines the mains are normally out of round on 1 & 6 by 3-4thou this would indicate that the crank is flexing through its length.

    A girdle will go a long way in reducing crank flex and hopefully help bearing life, as for using an RB girdle this would be a monumental and expensive way around the problem as you would need to line bore the main tunnel which in impractical and the man that built this girdle was no fool and also built some of OZ's best L series long before most of us had Z's or knew how to build motors!

    I have found that the arp studs are better but I still had rear main leaks .

    Have found that the block brace is a great help at reducing bearing wear and the rear main nearly stopped leaking.

    Also I have found that the Arizona sump has been a big help at stiffing up the bottom end as the rails are pretty thick.

    Also guys at electromotive ran dry sumps which would help as they would have run vacuum in the sump and their engine would have been rebuilt every time they went out which would help the situation.

     

    Hence my confusion.

     

    The way I see it, its like saying.

    Don't put a roll cage in your car as it adds weight.

    Or, Don't bother using forged rods or pistons as the factory units can handle 500hp.

    True but the advantages outweigh the negatives.

     

    Wouldn't a stronger bottom end give you better reliability/durability?

    Not starting a storm in a tea-cup, just trying to learn

  4. Hmm... now where have I seen that kind of design before. :blink:

    Maybe he should remain nameless too. :D

     

    I have been driving my car now for 3 summer and so far no problem... or maybe one set of piston rings only. :D

    No idea, where have you seen the design? Got a link?

    As stated, nameless due to respecting privacy. Some people don't like their names posted all over the Internet.

    This is aimed for modified engines for track use. Not really necessary for street in my opinion.

     

    After some engine builder and/or engineering critique/input?

    Usually Braap, TonyD or JMorteson would pitch in, where are you guys?

  5. It looks intriguing but the only benefit that you actually described was moving the harmonics up in the RPM range (even that is kind of subjective). Most of what I've been reading implies that the L6 block is very rigid as designed. Do you have more measured numbers or descriptions of the benefits of adding a girdle? Might generate more interest and discussion.

    Reduced crank flex is also claimed. More so for cylinder 1 & 6.

    How many Z's have s leaking rear main seal?

    Original designer claimed the girdle helped reduce these issues.

    I'm still in the process of building my engine, so don't have first hand experience.

    However, there is one fitted to a race engine here in Melbourne that is getting 193kW's at the wheels.

  6. These were once sold here in Australia and sent overseas, before I could reach the pedals of a car. The only reason they became unavailable is personal reasons for the original designer/manufacturer, a family friend of mine. He used to be a well respected racer and engineer, who still holds lap records to this day. While having a garage clean out, he passed on to me the design for me to use and manufacture once more.

    He shall remain nameless, as a mark of respect. Life takes you to funny places and he is no longer interested in cars.

    Now, his experience was that he DID get benefits from the use of a girdle. He claimed it gave better rigidity in the block and crank, aswell as acting as a bit of a windage tray. Also said that it moved the harmonic vibration further up the rev range, which also changed the sound of the engine. He was a smart cookie and never did something unless there was a reason.

     

    After modelling the design on CAD, I have started making small batch runs made from high tensile 6mm steel plate. If there is enough interest, I can make more.

    Spacers are required to bolt through to the mains caps, ARP studs or even Unbrako socket head cap screws with hardened washers have been used.

    You can see there is provision to drill and tap into the webbing of the block, using countersunk screws. Or if you are using a sump like Arizona Z car's, just bolting that through should suffice.

    You can use a modern sealer like threebond instaed of gaskets.

    That's about it.

    The way I see it, I have spent thousands on parts to make my car go faster, it is a bit of insurance to "look after" my investment!

     

    What are peoples experiences and thoughts?

    post-3271-041510500 1301526103_thumb.jpg

    post-3271-017360300 1301526121_thumb.jpg

  7. Maybe I should throw the cat amoungst the pidgeons and remind them of that electramotive L28 turbo!

     

    I've heard and read about the PCV issue, that could well be the problem they're experiencing. Would they know about it? Dunno? I'll suggest it and see who says what. Thanks Tony.

    The gentleman who designed and made these years ago was a clever man who raced these with great success and reliability!

    The issue is not just block flex and reinforcing the rear mains, but also crank flex/whip and harmonics.

    Then there is the builder who is for these locally, he himself is no dummy. Working with Gibson motorsport here in Australia back in the day, still in the performance tuning industry 20+ years.

     

    For me the price of the girdle, compared to the price of a complete performance engine, is negligible.

    I see it as extra insurance as we all cannot afford a rebuild after events!

  8. So I have a choice of manifolds to use with my new triple 44PHH Mikuni carb's. (bought from Sam280Z)

    The Mikuni as discussed in this thread and a TWM manifold (longer than Mikuni manifold) which is the same port size as my N42 head.

    My L28 engine is running an aftermarket cam (72° & .49" lift), Ø88mm flat top pistons and balanced bottom end. Currently running 40PHH Mikuni's on a Cannon manifold (which is longer again).

    I'm also going to use a TWM cold air box with 50mm velocity stacks.

     

    Am I better off using the Mikuni manifold as supplied or the TWM one?

    Am I better off to port the Mikuni manifold, as it is not a standard L28?

     

    I'm concerned about the shape of the Mikuni ports. Short runner with sharp bends and lip with reduced port exit. It goes against all the principles I've ever beleived in...... :unsure:

     

    Note,

    My car is used for club events and sprints (track days) only.

  9. As the title states

    After 3 44PHH Mikuni carb's, I'm prepared to rebuild them if that suits.

     

    If anyone could point me in the direction of someone who could help me out, many thanks and good karma may follow you and your family :)

     

    thanks guys,

    Simon

  10. Hi, i've done a search, but can't find the info I need.

    I have an L28 (N42 F54) with the following specs.

    Ø88mm flat top pistons (2mm oversize, which makes it a 2883cc)

    0.49 inch lift 74° cam

    balanced bottom end

    recurved and mechanical advance dizzy, set to 15°

    Extractors to 2.5" exhaust

     

    I am running triple 40PHH Mikunki's, what jets do people you recommend?

     

    Currently running

    Choke ø36

    Main Jet 160

    Air Jet 200

    Idle/Pilot 57.5

    Pump 45

    Block OA

    Bleed pipe T

     

    I have a selection of jets to choose from

    Choke ø32, ø36

    Main Jet 140, 145, 150, 160, 190, 200, 210, 230

    Air Jet 180, 200, 210, 230, 240

    Idle/Pilot 55, 57.5, 60

    Pump 40, 45, 50

     

    I sorted a flat spot down low by going smaller idle/pilot jets (60 to 57.5)

    Looking for help at top end, seems like it wants to go, but is lacking fuel or air, or both.

    Can someone give me an explaination as to what effects the main and air jets will have on performance?

     

    Thanks, Simon

  11. I'm in the process of collecting parts to rebuild an L28 with F54 block and N42 head. Its going into an S130 for club events, ie sprints, hillclimbs and club runs.

    I have most parts, just after-

    -Std flat top piston rings (moly)

    -All bearings

    -Welsh plugs

     

    Would prefer to get all in one hit from one person to save on postage.

    Shipping to 3138 Victoria, Australia

     

    May need more parts as I think of them, I have most out in the garage already.

    Thanks, Simon

  12. Can anyone recommend a good place to buy some parts to rebuild an L28?

    I'm after -

    Timing set

    Bearings

    Gaskets and seals

    Lash pads

    Pistons and Rings

    Bolts (conrod, head and mains)

    Oil pump

    Water pump

     

    Please advise me of anything else that I may have missed

     

    I'm after best bang for buck here and delivery to Australia.

    Thanks in advance,

    Simon

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