ozconnection

I've just finished putting a square header onto a round port exhaust head. I swear it makes absolutely no difference. No leaks. The liner in the round port makes it much smaller than the square port header opening. As for a square port and round header...dunno but I have the feeling it may not work quite as well as the other combination. I could be wrong.

The Arizona isn't a bad effort really, the runners may not be all the same length as you've noted but they do 'tune' themselves at a number of different rpm's that way. There is a comparison to exhaust headers here. Tuned length promote high end power at a particular rev range. (ie triple weber individual runner manifold) Interference, by design, don't offer a power peak as such but a spread of power over a somewhat larger and lower rev range. (ie Arizona four barrel manifold) Race vs street setups. Agreed, most performance carbs can be tuned to offer the best of both worlds to some degree. I just don't hear too many people tuning their triples for economy! Having, in effect, two carbs in one body just lends itself so easily for this kind of calibration.

True Leon, I agree with you with what you say. Nice pics too btw. I like my Arizona manifold because it helps boost throttle response and low rpm torque in my engine. For my streetcar, the two small primary throttles help with fuel economy because they can be jetted that way. The secondaries can be tuned richer for a more powerful top end. The manifold divides the engine cylinders into two groups which allows a unique manifold resonance. This resonance boosts cylinder filling of air/fuel mix at low engine speeds. The floor of the arizona manifold is 90 degrees to the downward flow of the air/fuel mix coming out of the carb. Most street V8's running a four barrel carb will have a manifold floor that is also at 90 degrees to the flow out of the carb. Whilst not optimal for a RACE motor, its more than acceptable for a STREET motor. Just ask Ford, GM, Chrysler etc. An acceptable compromise, especially when there may be other positive attributes which will sway the decision not to use a race style induction on what is predominantly a street driven car and one that I'm very happy to live with.

Exacto!

Getting closer now....

That's some solid info right there! As far as the accel pump setup is concerned, it's way too big for our little sixes. The volume of fuel that can be delivered by the accel pump can easily flood our engine. The carbs were originally designed for a much larger capacity engine, so some fuel delivery reduction...in terms of volume.....needs to be done. The way I do this is to adjust the spring loaded screw and unload it, undo it so that there is much less travel on the swing arm on the bottom of the bowl/accel. pump. The effect is to use only a percentage of the volume of fuel stored in the diaphragm. This is not the way Holley will tell you to set it up. You'll find a point at which too little fuel is delivered and a bog or hesitation will be felt. To correct for this, screw back in the spring loaded bolt a few turns and compress the spring a little. Try your engine/car again. Driving is the best measure, to see if the setup is working properly. Winging the throttle in neutral isn't the answer. I change my secondary springs. I start with the heavy black one and work, one at a time, progressively lighter, until I feel a bog or sag again. Then I swap back to the one before it that doesn't sag....all done. That's pretty easy to do. Your secondary carb tune may effect your mixtures, so I suggest you get a WBO2 sensor with data logging and do some freeway cruising and accel testing. Even though you may not feel it, the mixtures may lean or richen out and that may suggest that some larger or smaller secondary jets may be needed. Data logging will allow you to go home and sus out whats going on without fear of having a crash whilst driving, checking this, looking at that etc. Get to it..have fun

The Holley book by Dave Emanuel is the first Holley book I ever bought. It is a good starting point. There are others out there and i have a great collection. They provide different perspectives or solutions and that is what I'm often looking for in a new book. Changing jets from the 390 into the 600 shows that you're willing to "get stuck into it' but again I say with respect, you gotta know what your doing man. You cannot simply change the jets over like this. The effect is so dramatic by 20 jet sizes, you'll never get the engine to run right, it'll be so lean it'll pop and fart like a bastard and you run the very real risk of burning the valves out or putting a hole in your piston. I cannot stress this point enough. Understand what you're doing by doing some reading up first. Put those 600 jets back in. Test running the engine in your shed isn't really tuning.....the only real way is to take it for a drive and drive normally. Not flat out but normally. Come to a stop and see how it idles. Drive it slowly and does it snatch/jerk? A slight uphill gradient, does it pull smoothly or does it have a flat spot where adding throttle doesn't result in more power? How do the spark plug electrodes look after the spin...black or tan? Things like that. For me, to get the car where I wanted it took some weeks of weekend driving. Each trip was for 20-30 minutes. A 2 minute blast around the block barely gets it warm so you'll never really get to see whats wrong or right with your carb. calibration. Change one thing at a time. Then try it. Write this in big letters across your forehead if you have to. These few words will be the best advice anyone will ever give you. Don't forget them or it will take longer than a few weeks to tune your carb. Take detailed notes. Make notes of how the car went/felt after the 20 minute drive. Leave yourself impressions. Score things out of 10 for example. Idle hot 7/10 idle cold 9/10 slow running 7/10 sudden accel 9/10 etc. From this you might conlude several things....don't tweek the idle screws, the auto choke setting, the power valve all at the same time, do one thing and then rescore. You might find things improve where you thought things wouldn't and at this point you'll begin to understand the interrelationships between the different circuits inside the carb and how these circuits "overlap' each other. Get that book and start learning. You wouldn't sit an exam without some study first would you?. Give yourself the opportunity to succeed man. Cheers!

A quick reply....an electric fuel pump can be a good thing...you can check the float levels without the engine running, for example. An ignition upgrade is simple and effective for ignition reliability and consistancy. The jet kit you mention, what parts does it have? Jets won't effect the idle. Get the idle right. You may need to go to your library and borrow a Holley book or two and read up on the subject if you don't have much experience. If you have time...then take it...don't rush. Understand what you're doing. Throwing parts at a carb doesn't mean success.

Genuine Nissan E32 intake manifold. You can't just go and buy one of those E32 manifolds, it took me quite a few years to find one AND at the right price. That injection throttle body (with megasquirt) is for a future project I have in mind for my coupe. You can buy those on ebay. Cheers.

E32 manifold and with throttle body injection for something 'different' .

Boys, please help the guy out here...some people like to do things a bit differently and that should be respected, not dissed. AND my 4 barrel Holley setup runs beautifully,. Took some work but the fruits are there for my effort. Magic doesn't happen without waving ones wand. There is a small but loyal following of people running 4 barrel carbs on their sixes. Not all of them run Holley's but most do. I do. The most significant thing about running a 4 barrel is the manifold that it's bolted to, not necessarily the size of the carb you use. The effect of the manifold is dramatic in the way the carb has to be tuned. The V8/carb boys understand this the best, they know an 850 double pumper wont work well at all on a high rise single plane manifold on a 4V headed Boss 302 Cleveland motor for the street, for example. However, with the same carb, a dual plane torquer manifold will be far more civilized than the other manifold. The jetting and power valve values will need some adjusting too because of the reversion effect and harmonic tuning that takes place when you begin to separate the firing into two groups, like you do when you apply a dual plane manifold to an engine. Detailed theory is out there if you want to dive into it that much. What the HELL has all this to do with our engine, an inline 6 cylinder? Lots. The manifolds that can use a four barrel carb are out there. Did you know that NISSAN made a 4 barrel manifold for the L series six? They did. I have one. It was an evolutionary thing from the down draught 2 barrel carb that nissan designed for their domestic and some export market cars that had sixes in them. The 4 barrel verion was fitted to a domestic market car only. Arizona, Clifford and Cartech all make manifolds/adaptors for 4 barrel conversion. Depending on what you use will determine what type of 'induction' you'll be left with. The Arizona will be a true 'dual plane' setup, the Clifford a single plane (can be modified into a dual plane) and the Cartech will adapt the twin su manifold to a single plane type manifold. A dual plane manifold will never have the top end of a single plane or that of triple carbs but a Clifford single plane can match a dual su carbed engine setup for top end power. A 600 cfm carb will work on all of these manifolds. I know, I've used one. The top end was great and I achieved over 103 rwkw in a stock N42/N42 combo through an auto trans (L3N71B) with the air and steer belts on and the fan in place. Why don't I run this on my car now? The response down low was average, economy average and if get really picky, thought that I could do better. Power at the top end isn't everything for a daily. For the track.....fantastic....but not the street. The process continued, testing this one, combining it with that one and ended up with a 465 Holley on a Arizona dual plane manifold. My old Cedric weighs in at almost 1500kgs. For a responsive drive, I chose this combo. It's fantastic...reliable, economic, torquey and 'different'. In summary, you can use a 600 and on an Arizona manifold, it's not bad, you'll just need to work it to get it to work as you'd like it to. No free lunch unfortunately. Good luck with it mate. Cheers.

If they're rare, which they are, then the value must go up. It's good to have something that few others have or could easily acquire. The option is to put in a more modern engine, lower it, put some brakes on it and paint it and they look go stop and handle very nicely. OR restore it to original condition. That's also very cool. It's a matter of personal choice. As far as the steering boxes goes, there is some miss-information here. The 230 series steering was assisted by a hydaulic ram setup on the draglink, not intergral like the 330 series steering boxes. Therefore it's only the 330 steering boxes that are what the Ford guys look for. And, why aren't you looking on Ozdat? There are heaps of us guys there already, with 230 sedans, coupes and station wagons......all great guys and willing to help you out with their own personal experiences with these cars. See you on Ozdat mate!!

The d6k8-22 is a 1980 california model electronic distributor from a 280ZX, for both auto and manual shift trans. It has 17 degrees mechanical advance and uses a vacuum advance with 30 degrees. (wow, that's heaps!) That's pretty good Leon off the top of your head.

With a Holley carb, I have a combination of lithium grease on the linkage and graphite powder on the cable, the same stuff you use for door locks etc. Proper lubrication is essential as noted by the others. When removing the linkages from each oter I use an open ended 10mm spanner under the ball. Even pressure is applied to both sides of the ball and it pops off without fear of breakage. Works for me! HaHaha.

I believe the trick here is to get 'even' rub all the way along the journal. A piece of rope will apply too much pressure in one area and not enough everwhere else, potentially doing more 'harm' than 'good'. You could try a flatter material such as a carefully cut piece of rag or a fairly wide shoelace or similar. My real solution would be to take the crank to a machinist and pay the man a few pennies! Piece of mind.

Yeah Arne, I've just changed from Brad Penn break in oil which is a straight 30 grade to their multigrade 20w-50. I'm like Guy and was looking for a semi synthetic oil with a high zinc content. Oil consumption hasn't been an issue and I'm very happy with it.

...and a Happy New Year to you and yours Guy!! Cheers mate :classic: The head combo sounds very solid indeed. I've read about that head mod and it seems to be a great idea, a more modern chamber WITH a higher compression ratio. Awesome. Were the SS valves oversized? Trust me, you'll be itching to put that 'mystery motor' in ASAP. I couldn't tell you I'd been to the track without showing you. It's moves along nicely with 8.3 compression and a stock "A" grind cam though. Can anyone say 'turbo'

Hello Guy..........what's the latest on your engine buddy........updates please? I've got my engine in, run it in and have taken it out to the track for some action already! Oh, you'll love your engine if mine is anything to go by. http://youtu.be/nMcCqok4Co4

I hate the spray bar oiling setup. Somewhere I've read it's superior......superior to what? Superior to internally oiled? Hardly when cam lobes get wiped with the darn thing falling to pieces because of engine vibration. People say the rod bolts are the weak link in the L engine....I think this one is just as weak. I've never had any issues with the internally oiled camshaft. That's always been reliable.

Yes, I'm with Fastwoman on the idea of safety first. I had a similar situation where one of my idler pulleys for my A/C was making noises like yours. Once the bearings were removed and I had them in my hand, there was absolutely no way of telling they were the trouble makers.....only at operating speed, they were noisy! Well that helps a lot doesn't it!

Remember this is a US based forum.....they don't get what we have and visa versa I'm running an L28 with VG30DETT flat top pistons (87.5mm vs 86mm stock L28 size) stock Nissan HG and an unshaved P90 head. Does not ping at all with 20 degrees static on the dizzy with premium fuel and an "A" spec stock camshaft. I calculated the compression ratio to around 8.3, it isn't but will be turbo'ed. Runs beautifully.

How can that be?

Fuel mixture ratio's will influence your engines knock thresholds. The stock cam won't help your knock situation, too much cylinder pressure because of a lack of valve overlap unless you use high octane fuels, water injection, retarded camshaft timing or run very conservative ignition timing which leads to......... Get a 'dial back' timing light. I bought an Innova from ebay and it's tops. You can plot the advance curve verses the rpms to create a simple 2d map of your distributor advance curve. A good starting point if/when you later run an ECU controlled ignition setup.

Willing to share your investigation? Might turn out some interesting perceptions.

You can do it but it's knowing how and where to do it which is the important bit. Can I suggest you get the book "How to modify your Nissan/Datsun OHC engine" by Honsowetz if you haven't already got it. A good read and will answer all your questions in regards to rods, cranks pistons etc. Or you can search this forum and/or Hybridz. This topic has been covered many times. Good luck with your project.