Lazeum

To balance the flywheel, the machine shop who took care of my crankshaft had to balance the crank as well. It was a 400€ bill I wanted to make the stock flywheel lighter but balancing operation cost was too much... the reason is they had no way to lock the flywheel in a machine without crank so it was their only option.

My setup design will depend on crank trigger wheel. I might end with Derek's design at the end... It's always good to get pictures from others. I'm collecting EDIS setup & VR sensor pictures for 6 months now ! For the flywheel, I thought about that but I wasn't sure yet when I was building my engine if I wanted to go EDIS. Since my 6AL box has fried, I've changed my mind It looks very clean & subtle, I like it a lot!

Just to let you know, EDIS + Megajolt should be home quite shortly In the mean time, I'm working on my setup. I'm getting inspired by Derek's solution & lesson learned from you, Nigel. here's the concept so far: and this is how my support looks like for now: It is getting close. I'll take some measurements from the EDIS kit to come to adjust everything. I will make a carb board template first nd then kick off the fabrication in aluminum. It should work nice at the end

I just came back from my investigations for timing. 1- the TDC is not where the 0° mark is which makes total sense. I stuck a rod in spark plug hole #1, when 0° mark is in front of indicator, piston is not at TDC. It happens before which makes sense since idle timing is measure at 45°. So TDC is most likely 30° before 0° mark. 2- Pulley is in good shape. No sign of rubber being torn apart. I put it in a vice, locked the hub with 2 bolts and I wasn't able to make the pulley move. I've tried as strong as I could. 3- 0° mark seems actually in front of the cover indicator when the notch for pulley cotter pin in vertical. It is a very gross adjustment since I haven't measure precisely. I've always though TCD on piston #1 = Vertical cotter pin groove. So I don't understand what is happening. I just know the engine is running great and I can't measure timing properly. So I guess I'll leave it alone for now (I'm going to Megajolt anyway by the end of the year) It could be wrong pulley vs. indicator, damaged pulley (I've put paint marks on the pulley to control if hub rotates back to the outer piece). It is a crazy idea but I'm wondering if my top end wouldn't be out vs. bottom end. I can't see however how the engine would run that good with such deviation. I would need to check cam timing but I first need to get exact TDC position.

Thinking twice about my issue. I'm wondering if it isn't my crank damper going bad that would have slipped getting an wrong offset. Each time I start the engine, I've got a serious squeal noise coming from the alternator belt, could it be the damper? I've always though it was the alternator, maybe it isn't. The best way to check while everything still on the engine would be to check 0° mark at TDC by measuring piston position directly. I'll do it next weekend. It might be time to dump stock damper & get a new one (why not going with fluid damper then?)

Something is not working as it should on my car. Measuring ignition at idle gives me nearly 40° where the engine runs best. Anything below 30° and the engine runs really bad. The setup: - bottom end rebuilt by myself, F54 with flat tops, new pistons, new rings, new haed gasket (Felpro), etc. Quench gap is set at 0.8mm (0.032") - head is P79 done by Braap with Rebello cam & surrounding components - 3x 40DCOE tuned with a wideband - Ignition is done with Accel coil + Mallory Unilite (I just fried my Hyfire CDI 6AL box which is now out of the car - could it be related?) - The car runs great, pulls great, idle is solid, acceleration is smooth with no misfire or what so ever . Timing advance is set to 16-18° which should give me advance at idle around 14-16° & total timing around 34°. Before the rebuild, the engine was also set this way, measurement with timing light at that time was providing me expected results at idle around 16°, now it does not. - When I did install the part, I wasn't able to get the 11:45 position on the squill shaft the way it should work according to the FSM. So I set it up randomly, I just made sure cable for spark plug #1 was right in front of dizzy finger at TDC on compression stroke. So I should be good with timing. When Cyl #1 is in compression at TDC, I've got a good spark (which I have since engine runs good). - Chain install was done while engine was on the stand with the 2 bright marks installed the way they should. So I should be ok as well regarding this point. - Cam timing hasn't been done super precisely, so far it is set at hole #2 on cam sprocket (with notches exactly in front of each other). Bottom line: nothing is really wrong with my engine but measurements done with several timing lights (static & with advance knob) are all giving me irrelevant data so it is difficult to know where I am with timing. How can the engine runs good with 40° at idle at total timing around 56°? Something does not make sense to me and don't understand why! Please help! Â

This mpg was during 120mi trip on country side roads during end of break-in period (max rev. 4500rpm), not a track session with 80% of WOT action Carbs are dialed in with O2 WB sensor & small chokes (32mm). no bog or what so ever, engine is quite responsive when at WOT but there's some laziness in mid trottle action. Carbs balance is probably not the best. To get back on timing, my current dizzy allows me to adjust idle & total timing easily as well as how the curve is in between. Most of the power from the engine has to do with timing more than AFR. As soon as you modify the engine (VE accross rpm range to be exact), timing needs to be adjusted somehow (even if it works with stock units). That's the same exact reason, cam change on L28e(t) with stock ECU is not good. timing needs to be tweaked.

You're talking about economy & Max power at WOT but the vacuum advance would benefit a lot also with smoothness & torque available for partial throttle, this is what matter the most to me while setting up a street driven car (besides WOT, of course). I'm in the process to deviate from my Unilite dizzy I can setup with no vacuum advance (~20mpg for info) to Megajolt for that reason (and also because I'm bored playing with springs & screws to setup my igniton for hours & guessing )

I would suspect ignition problem: either your timing is way off, your alternator is going bad (the unit itself or some connections), your dizzy is worn out or something is going bad with your spark plugs/wires. Start by easy stuff such as spark plug inspection, if they are fouled, change them. Your problem could be that simple. However, you would have to understand why they are fouled afterwards (lot of cold starts or cold start mechanism not ok could be some of the reasons for instance) Have you played with ignition wires? are you sure to still have proper firing order? Can you move the base of the dizzy by hand? - if timing is off, something is probably loose. Is your alternator belt ok with proper tension & shape? Check voltage on your alternator? do you see battery voltage going up between engine stopped & running? Have you checked for leak around carbs? take a fuel hose, one end to your ear & chase leaks with the other end around the carbs & manifold. You could also try to spray carb cleaner where you could have leaks, it would make the engine run faster if you have a leak (clean a little your intake first if you don't want to have the dirts being sucked). Regarding gas, my Z sat for 2 years while I was rebuilding my engine & restoring my suspension, it started right up with 2 years old gas. I don't think it should be your focus. For your exhaust leak, it would make noise, it would vibrate but I doubt it would create the symptoms you're describing.

Good to hear first that I'm not the only one I haven't got any during the next oil change but it shows why it is critical to flush the oil quite after a small run to don't let the particles drop at the bottom of the pan. Good also to hear that my advice to drop the pan was probably helpful.

you're welcome & I'm glad to help serious shops to do some business

See the following link: www.clarksdiscount.com The owner has been great with me, I'm located in Europe. Parts were ordered on Monday, they were at home Friday morning. Emails were all answered within 24hrs & he's having tons of parts for our Z's at very decent prices.

Stock & Felpro are 1.0mm thick compressed. I've measured both during my engine rebuild. You should not use gasket thickness as an option to bump the compression ratio. You should use your head, your block & pistons/rods for this. I have machined the top of my pistons to match my setup: block resurfaced, milled P79 head & flat top pistons.

I install & remove also the stand head while the block is on the floor. I've also tried to install the block on the stand while it is maintained in the air with the lift, it is not convenient.

If you keep it n/a, Felpro gasket is enough. I'm running L28 planned to push around 250 crank HP, I've got a felpro gasket.

I was able to lift the block by myself alone & loaded it in my DD during the rebuild. So you definitely don't need any tool to lift it with 2 people. Just wear some thick gloves to avoid being hurt by sharp edges. and to answer your question with a number, my guess would be around 90-100 lbs.

I'm interested in the results from your observations. For your information, I purchased ITM flat tops pistons for $180. If your engine is out, cost is not something that should stop you upgrading those if you're looking for stock style pistons

I haven't thought about this quite of phenomenon but it makes sense. The adjusment is less severe that it was at first. I'm at the 3rd one, always cold with lash at 0.005" at valve (setup at 0.008 at lash pad). The head was done with 5-angle chamfers on valve seats + new valves. Unfortunately, I'm stopped in my break-in operation; my ignition stopped working (CDI Mallory 6AL box, Unilite Dizzy & Accel coil), so it will be root cause analysis enjoyment this weekend...

So basically, until valves are not matching perfectly the valve seat, would I have to check valve clearance?

I haven't seen it on hbz, check out the link below for the craftsmanship & the details shared of the build. I think is it amazing & worth sharing even if it does not have any pistons => 4-Rotor FC Build @ rx7club.com

To break in the engine, I started with a first run for 5 minutes at 2000-3000 rpm. I then flushed the oil right away. I had a leak somewhere (it appeared to be the gearbox being overfilled) so I took off the pan to change the gasket I thought was defective. I saw a lot of particles in the pan I've removed in the process. this is what I got: those are iron/steel chips. I've always made sure everything was super clean during the assembly process! I believe that's a lot of burrs I did not expect. The oil pick up was also 30% clogged because of paper towel pieces I have missed during the rebuild (mostly on casting edges - not so visible when they are soaked with oil). So next oil change 300 miles later, I redid the same process to control oil & burrs since those did not come with warm oil the first time. Thankfully, no chips or burrs were in the oil anymore so I'm not going to repeat this process anymore but it was good to check at least once. Without removing the pan, those chips would still be in the pan or worse in the filter after being through the oil pump that could have been damaged. Regarding the gasket, I coated both sides but very lightly. I used a "cork" style gasket (what I have available here), it was just darker due to gasket coats laid with the tip of my finger. Obviously, I also put some at front cover edges & on rear main bearing cap edges.Â

That's a good tip I haven't though about!!! I'll give it a shot next time I work on the car (next weekend)

I had the same feeling with E46 M3. I had at that time for DD an Evo 8 modded with stock turbo. It was a +300whp AWD on-off machine that was amazing to drive (very quick steering, quite stock stiff suspension, very good grip, good torque) It was as powerful as the M3 but far more rewarding to drive. I was able to spin tires with 2nd gear, friends did not want to go in since they were hitting their head against seats at each acceleration . Mileage was poor however, less than 20mpg average. But still the Z is much nicer to drive and I don't have a v8 in it (L6 with triples)

My engine is freshly rebuilt with new parts everywhere including cam, retainers, pads, springs & valves. It is a F54/P79 combo with flat tops & Rebello cam + surrounding components. Lash is advised to be set at 0.005" (0.13mm) at cam cold. I'm doing the check at lash pads with clearance set at 0.005 x 1.5 = 0.0075" (0.20mm) I'm checking valve clearance every 200-300 miles. I found some valve clearance being very small (almost non existent), below 0.05mm at valve whereas they were set around 0.20mm (everything done cold). Others remain within specs. I'm doing the job with a torque wrench and the corresponding tools. lifters are clamped at 60N.m. I haven't found the torque specs in my 72' manual so I went with 280z manual. I don't think it should act this way. It seems heat cycles make the lifters becoming somewhat loose & becoming higher (torque to unclamp them is still very high, it is still hard to do with a simple wrench) Is there something wrongly done? Is there anything else I should check to make sure I'm ok...

For the pan, I start to get use to it since I remove it each time I'm doing a oil change (because of engine freshly rebuilt) Mine was leaking because it was not flat anymore. I had to flatten it again with a piece of hard wood. I also put some very light coat of copper silicone on the gasket. It does not leak Mine is a stock piece, I can do it without being bothered by the engine block or the front cross member.