ozconnection

Hey man, seems you have a good handle on what you're doing. I thought about your option of sinking the exhaust valves deeper into the head to clear the valve stem seals from contacting the retainers. That certainly is an option. Using the "A" series seals is also a good option. Now it boils to costs (sinking the valves may require spring seat shims to get the correct valve seat and full lift spring pressures) and whether or not you ever intend on using a different cam in the future that has a higher lift than the one you currently working with. It'll be good to see some you tube action (or a dyno sheet) of your work when your done....I'll make a point to turn up the volume on the speakers All the best Guy! Cheers.

Guy, I got a head back from a shop once where every valve in the head was sunk to a different depth. It took many hours to get the wipe pattern the same on all the rockers but I did get there. I then ran the engine and it worked perfectly in all aspects. Your job will still take some time as I would mock up each valve to see if the inlets and exhaust valves are set to the same depth. You know this...assume nothing and then there are no nasty suprises Because you're centering the wipe patterns on the rockers with different lash pads, you're ensuring a correct rocker ratio for each lobe/valve in your head. All valve lifts and durations will be the same because of your efforts here. Good luck mate...all will be well with your attention to detail (not all reconditioners understand the 'geometry' needed for the L head... unfortunately!) (PS Stock cams or those with small valve lifts are ok but be more cautious with aftermarket grinds. The lifts are higher and the durations longer which could bring the valves closer to the piston crowns. Any contact with the piston usually occurs with the exhaust valve as the piston chases the exhaust valve at the end of the exhaust stroke.) Are your bores notched for the larger exhaust valves your going to use? I know L26 blocks are, but I don't know about L24 blocks. Someone else can chime in if they know this stuff better than I do. Cheers :classic:

Sounds to me that your new engine it's running nicely! Does you engine ping? Does it get lousy economy? Does it start nicely and settle quickly to a nice and smooth idle? Does it have good throttle response? Does it make good power? (yes, I know its a fresh engine) Can you see where I'm going with this? How much 'better' can you get things with what I assume to be a stock distributor? Sounds to me like all is well there, spend your time and money on a better balancer, a defective one will cost you a lot more than a 'defective' dizzy. Wobbly balancer...now that doesn't sound very reliable....at all. Just my 2 cents Cheers

...under load......on the dyno........or...........like this Love what you've done with your exhaust man! I'm that close to doing it on my car, I'm waiting for my current exhaust to expire so I can justify the changeover. Cheers.

Cheers my friend! :classic:

Ooooppppps, sorry gentlemen for giving you wrong technical advice on the harmonic balancer marks. :stupid: I guess this was a point of confusion for some and why Nissan decided to change things around down there to the later setup with a single notch on the balancer and a timing plate on the front cover....it seems that I too fell into that trap. As far as the idle is concerned, timing around 15 degrees should be fine. I 'tune' the idle speed by listening to the exhaust note. If the note is smooth like mmmmmm, then timing is OK. If it starts to go mmmmmmpammmmmmpapammmmmpammmm then chances are you're too far advanced. This check is done with a warmed up engine and the carbs in good order and tune btw.

Do you own a timing light? 180 degrees out will not matter a bit if your leads have been moved on the dizzy cap. What that means is that where number one lead goes normally, it has number six lead, where 5 normally goes now has lead 2 etc. HOWEVER, what you told us when the cap is removed was that the rotor button was pointing to number six which was facing the firewall. Your engine is not on top dead centre on number one cylinder, your on six. Keep the dizzy cap off as you turn over your engine until the rotor button begins to point towards the radiator. Check your balancer as this happens. The FIRST mark on the balancer as you approach TDC is Zero degrees. (the balancer spins clockwise when the engine is running, so the first mark has gotta be TDC) Remove the spark plug on cylinder one to verify compression as you do this like doradox said. Have a look at your cam lobes now, they should be pointing up, one at 10:30 (in), the other 1:30 (ex) Good luck!

If the 280 engine is what you want in there, then use that along with the loom etc from that engine. The 280 engine will have more power and torque than the 2.4 that you have, regardless of kms or manifolds etc. Swapping manifolds between the 2.4 and 2.8 isnt worth the effort IMO. Good luck with your project mate.

FYI, not all the coolant goes directly through the thermostat in some models of Datsuns. In later models, Nissan put in a bypass line from the thermostat housing to the inlet side of the front cover just before the water pump. This setup was designed to lower the pressure of the coolant in the block so that excessive pressure wasn't forced through the engine before the thermostat cracked open. An example is pulling straight onto the freeway, accelerating up to speed, using revs to do so and with the engine cold and thermostat still closed.

How old is your water pump? I've seen old ones where the vanes have eroded away from not using proper engine coolant and the water pump dies a slow death. Remember it's the coolant that carries the heat away from the head and block to the radiator and a faulty pump might be the problem.

Agreed, but what's causing this to happen to his engine? Strange! In the meantime, you could try a hotter plug to get it to idle better.

What was the mechanics conclusion, and why was it there?

Electric fans can be made to work. The 16 inch unit you have sounds like the same size one I'm using. I have three heat exchangers at the front of my car..a radiator, of course, an a/c condensor and an A/T cooler. Surprise, it works brilliantly and has not failed me. However, I set up my fan on the engine side of the radiator. It is contained wholly within the factory radiator shroud to all look very factory. The fan has been slotted into position as close to the radiator as physically possible without rubbing. Potential points of contact have had rubber 'shoes' added so that the radiator tubes and fins don't get damaged and when inspected recently, only a small section of black paint has been removed but NO damage to the radiator! I feel that having the fan close to the radiator improves the 'draw through' effect from the fan. The temperature regulation is handled by a rather simple electrical circuit using a relay, a fuser, a temperature switch (set at 80 degrees celcius) and some other connector electrical 'stuff' Since I also recently upgraded my alternator from externally to internally regulated 60 amp Bosch, where the voltage regulator plugged into the main harness was now a whole heap of power, earth and switched power lines.....ready for use......for anything! Have a go.....I was using an eight bladed fan with a Temcoupling clutch before but it was loud and like you I wanted to grap a few extra kilowatts and thought that an electric fan conversion would work. By the way, I also use water wetter, distilled water, an 87 degree celcius thermostat and a 20 psi radiator cap. My radiator is a 3 core unit from a Y30 300C (VG30E engine) and I use an LD28 water pump. And yeah, it works!

Exacto! :classic:

I like the slip in variety because of the smooth internal surface it provides. Anytime there is a mating point, there's the risk of an eddy creating step. On the other hand, I like the idea of bolting the stack to the carb for secure fitment. And the chrome look is nice. Do they come in different sizes? Are you looking to 'tune' your induction system at all? If you are, the slip in ones would be a snap to insert and remove quickly to find the best power and/or torque curve from your engine. Have fun.

A broken tensioner is possible but he'd be telling us about some weird noises up front and power loss due to erratic cam timing. More likely is that when a timing chain 'stretches' because of age and use, the front end of the engine gets very noisy because of the chain slap. I've never heard of a chain jumping a tooth, even when really stretched, ever. I don't really get why you couldn't get your tensioner tool into place Marty. Pushing the tool in will just push the chain against the chain guides, the same as normal! The 'y' shape of the entrance in that area lends itself nicely for a tool of similar shape to simply glide in and push the chain against the guides. Am I missing something here? Photos would help, for sure. Now that you've bumped the motor off TDC to get rid of the slack in the chain, turn the engine back to TDC. You don't wanna take the head off before you do this, save yourself some extra pain later on mate . Stock valve springs and cams but more so with aftermarket grinds and H/D springs can 'flip back' or 'flip forward' the camshaft when turning the motor over by hand, leaving what looks to be a loose chain on the straight side. It doesn't need to be much at all. Seen that before, many times. There were no other suggestions as to why you might have a problem Marty were there? I would be surprised to hear that you've done any damage here, you would've had other issues for sure. I just think it's a case of camshaft 'flip forward'.

Get yourself some transmission hose and rig up a cooler in front of your radiator. It's a snap really. Just make sure that your cooler is very close to your radiator without an air gap between the two. Doing this will force frontal air to go through the cooler and not around it.

Just watched your vid........AWESOME! I really like the sound from your pipes, well done. :classic:

Those numbers are spot on Guy! Thanks for the achnowledgement! :classic:

Setting yourself power and torque figures you think you need is always a recipe for disappointment. What, if after spending heaps, you have only 220rwhp? Will you be happy with that or feel like something is still missing? Don't do it man. Read heaps, like you've done and be happy with your end product. If it puts a smile on your face, does it matter, really, how much power or torque the dyno says you have???? Another way of looking at it is that a 3.1 is inherently a torque monster as you know. Very little is needed to enhance that characteristic. Stock heads and cams foster low rpm torque. Big revs, cams and heads are needed to achieve the power levels you seek and consider all the associated expenses with building a high rev / high horsepower engine. A P79 head will work but don't wreck your quench by using a too thick HG. See if you could possibly get some chamber work done to drop your compression ratio down a bit if needed and use a stock thickness HG. Have you calculated your anticipated C.R. yet? Then factor in what type of fuel you'll be using and what efi/ignition setup you'll run too. Lots to consider....have fun! And finally, Torque is cheap, power is expensive. .

Thank you for posting this! Thank you also for pointing out the relevance of Z trains attachment. Hmmmmm, it seems what I said about temperature stabilization may in fact be fact! For all intents and purposes, what I say here in these forums is based on my own personal experience and technical research. I will not make comment on something that I'm unsure about or have no experience on, that's where I'll sit back and read what other people have written. If I think something is awry, then I'll look it up and post my point of view. That way, I'm sure that others who are interested and read our posts get accurate information. After all, isn't this what it's all about Z train?

Too bad you live too far away for me to lend you some books from my own automotive library. You would find some of the information contained within those pages very informative. Oh well....

Are you in too much of a hurry to post a reply to actually read what or who wrote what? I'm the guy who suggested the water shut off valve. :stupid: Maximum engine wear occurs in the first few minutes after start up. This is fact. Why do taxi cabs have engines that run for over half a million kms? Because they hardly ever cool down! EFI inlet manifolds are very different animals to carb style inlet manifolds. The weakest link in the carb induction system is the carburettor itself. Design features that are built into the factory style carb induction system are there for very sound engineering reasons. The 'performance' you speak of is only part of the overall big picture. If you were to specify 'top end performance' as the only design critera, then yes, remove the coolant lines to the manifold. This is fact also. However, the word 'performance' can also be used as a much broader term that encompasses such things as 'start up', 'warm up' and 'fuel efficiency'. Besides the faster warm up times and less engine wear, the factory warms the carb manifold because it allows for a sustained induction system temperature regardless of the ambient temperatures the car engine sees. What this means is that by knowing how dense the air is based on temperature, a much more precise AFR can be achieved through finely calibrating the carburettor. A carby engine requires air temp stability since there are no air temperature sensors that can send an electronic signal to determine how much fuel has to be added under varying conditions (including altitude) when managed by an efi computer. Basically, when it comes to emmisions, carbs have a much harder time meeting emissions than efi do. No contest really. A 7th injector is a warm up device. It was deemed to be somewhat inefficient since the cylinders closest to the injector ran richer than those further away. Recall that an efi manifold is a dry manifold and isn't designed specifically for wet mixture flow....here is the compromise. With more modern setups, the duty cycle of the port injectors is increased to allow for richer warm up mixtures and the 7th injector was deleted. With either system, carb or efi, warmup still exists and significant wear takes place but the efi management system works more quickly to get the engine to proper operating temperatures. Oh, and using a petcock to drain coolant should be something found at the bottom of the radiator only. You don't want to potentially allow air leaks into your cooling system at any time between flush and refills. Even removing the radiator cap should be avoided and coolant levels should be checked in the overflow tanks/recovery system only. (Just like modern cars bro!) I'm done

Sure at start up with a cold engine and a cold day, everything is cold. Once the engine cranks and fires, the coolant will begin to heat and immediately begin to warm the intake manifold and the induction charge. Its at this time, in cold weather, that this kind of setup is valuable. Obviously, its the time it takes to get the engine to full operating temperature that is different with both setups and the amount of potential engine wear that also takes place during this time, especially since the choke is on supplying a rich mixture, washing the cylinder walls of oil, causing wear and soiling the oil with excess hydrocarbons........ Warm up the engine quickly to minimize this! So, it's not 'start up' where there is a difference, its 'warm up' where the advantages are. Didn't I allude to this in my last post?