luvemfast

Any updates on this? I've just installed mine over the weekend. Ran pretty bad, had to re jet the carb's. Then went like sh*t out of a shanghai. No dyno sheets yet

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?

140mm

How much were these items?

I've actually wondered if they where north or south of Tokyo, obviously south. Glad that they are ok.

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

Sorry Tony, but I've read through the other posts found here Doesn't really answer my questions. The answer 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. 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

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?

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.

No expert opinions on this topic? I find that hard to believe.

Thanks Jake, guess I should have done that too........

New topic started on Girdles

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?

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!

So we run the fuel return line through these fittings? Why did you not use them Sam? Would I be best to utelise them?

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

Cheers. But as I have a box of spare jets to suit Mikuni's, would prefer to stick to what i know. Will keep it in mind though if I have no joy. Still on the hunt for a set of 44PHH Simon

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

Been reading the triples sticky. Even though its not specifically for Mikuni's, there is still some useful info there. Thanks for your help with that, might need to get a wideband O2 set up.

No one? There is heaps of info on Webers and even Dellorto's. Find it strange for such a popular carby that there's no one who can help.

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

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

Cheers for that Thought that maybe someone here (mods maybe) may sell them.

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

If I was to do it again, I would shave/remove the rear wiper, with squirter and the antenna. Anyone want to do it? Would look siick! Also would like to put the later series 2 tail lights on.