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I don't see why you couldn't do the ATF thing now. It might take 24-48 hours for it to work. When you do start it, expect to see huge plumes of white smoke until the oil burns off!!! You could do this twice if you like, just to be sure. Be mindful that ATF can foul up spark plugs. Ask me how I know this. How much ATF to put in each cylinder I don't know exactly. At a guess maybe 10-20 mls. What I would do though would be to lift the passengers side of your car a bit more so that the engine block sits perpendicular to the ground. That way when you drop in the atf (via the spark plug hole of course!), the oil flows evenly around the rings to do their job. I would change the engine oil and filter after this too, just for good measure, you don't know what crap will be in your oil and what effect the ATF will have if left in the sump. Cheers

I just checked up on this thread to see how it was going....and it doesn't seem to have gone anywhere for a while. I was thinking about some sort of simple and practical 'test' that would prove this discussion one way or another. Grab a potato. Cut it down so it fits snugly in the tailpipe and cut a smallish hole through it so that some of the exhaust gas escapes when the engine is running. Simple. Of course, when the engine is running now, we have effectively increased 'exhaust system backpressure'. Take the car for a drive and see how she runs. Let us know how you get on!!

It's not from this guy is it? Please let us know more about that 'kit' as soon as you can!!!

The problem with Honsowetz book is that there is very little on fuel injection at all. That's a shame really because it's a good read. Maybe you could also read "How to rebuild Nissan/Datsun OHC engine" by Tom Monroe. An excellent starting point for those whom haven't built a lot of engines, especially the L series. A stroker engine can be fairly involved in terms of what to do and not do, and cost!. Maybe a little adventurous for a noob. :surprised Just my opinion. A proper freshen up of your current engine with a touch more compression, maybe a bigger cam, free flowing exhaust and a good tune with megasquirt or something will reap dividends. Keep reading around here and Hybridz for solid info. What you're trying to do isn't impossible man, you just need to arm yourself with plenty of knowledge. Good luck.

That's really strange for new Weber carbs. That's some kind of QC issue from the factory. Why should anyone have to tear down a new carb to see what's wrong? And they're not cheap. Go figure.....

I'm wondering how many of those people who responded on the poll with a 'engine needs backpressure' response actually have stock exhaust systems on their cars? Would that fact alone invalidate their responses in the poll?? "I don't like cheese" and "Have you ever eaten it?" would be my response. Equally, the question could be applied to our exhaust systems too, I think. Are we getting it all wrong when there is still such a high percentage of people out there how refute the notion of reducing backpressure loses engine torque? What will it take to convince those who still aren't convinced? Suggested reading and dyno results aren't having the anticipated effect.

Never used a clutch return spring in my car when I changed from auto to manual trans. Clutch pedal returned beautifully without it. Lighter pedal too, if that means anything to anyone.

5 verses 8 so far have said that backpressure in the exhaust is important to maintain low speed engine torque. Any thoughts from those people?

I agree with this. I substituted my original Nissan factory exhaust for a modified system a while ago now. I have absolutely no regrets. I wanted more low speed power and torque and that's exactly what I got. On another thread, "the great exhaust debate", I posted a dyno graph of the results of my new and improved exhaust system. Even then, I had a couple of people doubt the value of a well designed system. These people were well educated but simply refused to accept the truth in what was being shown to them. :stupid:Look at the graph, there are no 'dips' anywhere in the low end of the rev range, (dyno) proof to me that low backpressure really is the key to improving torque. Cheers.

Doradox, you've hit the nail on the head! The rotor button is 180 degrees out of phase with the factory set position. At some stage the distributor has been pulled down and rebuilt? with the spindle shaft rotated 180 degrees. Regardless, the engine will run without hiccup if the leads are positioned to account for this. Like I said before, replace one lead at a time and you would never have known any different. PS Don't tear out those pages!!!!:cheeky:

The simplest way to tackle this task is to remove and replace one lead at a time or take some photos of things before you begin. I had a look in my factory manuals and I can't see what your referring to. Can you advise as to which books/pages your looking at?

I guess red_dog007's original post is a little vague on what degree of 'performance' he was chasing. Maybe he could chip in. But as part of a hypothetical analysis of what parts should be included in a performance build up, things like carbs, cam, head and exhaust get the nod without even an eye blink. Then the guy who has just spent this great wad of cash starts blowing head gaskets on his 10:1 webered street monster. Chucks in more cash to get a bigger radiator because the temp guage says he should and the head gasket problem is not fixed. Takes out the thermostat because he 'thinks' this will help, but no luck yet. Hell, ARP head studs may fix the problem, but how much money and time has the guy spent and has he really solved the problem? Damn, what is the problem? Then he reads around the forums and sees that the aftermarket water pump that he bought is of such poor design that it doesn't flow anywhere near as well as the original Nissan one did (if you can still get 'em). So, not only does it not push as much water around but it also fluctuates in terms of flow in relation to engine speed. In a bane attempt to get the rotational speed of the pump right for high speed, a larger water pump pulley is used on the water pump. Great! Pump speed is optimal for 6000rpm. But everwhere else it's a lot worse and the gasket blows again because there isn't enough water pressure in the BLOCK and HEAD to prevent local boil from dead flow spots created by poor water flow from the pump! One solution....a water pump that flows the 'right' amount of water through the engine at all speeds so that flow is at a constant, regardless of engine speed. That way block pressure is restored, the thermostat can be put back in and the problem of buggared gaskets all but gone. Now the guy can spend a few extra bucks getting his electrical system upgraded. Why not, he's found the cash for everything else.....

I agree, many of the factory Datsun parts are suitable for performance orientated engines. I do ask the question as to why a company will produce an aftermarket part for an engine when there appears to be no reason to do so (read electric water pump)? And when there seems to be a need to have a performance intake manifold for EFI, nobody has produced a replacement en masse when so many people seem to think there are serious flaws with the factory unit? What's wrong here I ask you? So, back to electric water pumps. Red_dog007 asked the question if there was any performance benefit in using an electric water pump. I think the answer is yes. The L series water cooling system is not perfect and the engine was designed a long time ago. An electric water pump overcomes one of the problems inherent with a crank driven water pump, rotational speed. It's a big topic and there is a heap of information about this on hybridz if you want to find out more. All I want to say here is, look at the complete 'system', understand how it works and then look for ways in which it can be improved before you decide and tell everyone else that something isn't worth the money or effort. .

Electric water pumps do free up some power. I don't know of anyone who has actually measured the RWHP difference before and after the swap though. CSA make a dedicated L Series water pump that looks like its a quality part. I have one but not used it yet as it's for my next performance engine build up for my 240C. The idea of them failing applies to any engine component, so don't base your choices solely on this. The advantage may be in that one is able to run the pump at an optimum speed to avoid cavitation and significantly reduce the chances of local boil and steam pocket formation in and around thee cylinder head. Properly setup then, one can run higher comp. ratios without fear of detonation etc. So, it may not be a major power producer (or liberator) by itself but may be instrumental in helping other systems work closer to optimum. Same goes for the balancer. It will help the crank from self destructing due to harmonics so I guess its a good part to have unless you've got a lot of money lying around to build a new engine. Then, it wouldn't/shouldn't be a problem anyways, I guess. Cheers.

Thanks for the interpretation. Can you clarify this point AggieZ so that your info can be correctly understood and made useful for liltuber.

To give you advice as to how much power an L28 can make is dependant on so many things and your question is so open ended, you really need to do some research for yourself on the topic. There is a HUGE amount of information available out there but what you've got to do is read some of it first. Your understanding of what's possible with these engines cannot be answered with just a few posts from random people because we all have different ideas about what works and what doesn't. Not everyone will be happy with the tradeoffs that others are prepared to live with. Are you getting the message? I don't want to put you off asking questions like this on a forum based internet site but iIts a bit like school, the teacher will be more happy to answer your question(s) if it's obvious that you've done some of the required research first. As a suggestion to start you off, get the excellent book "How to Modify your Nissan/Datsun OHC engine" by Frank Honsowetz and start reading! Good luck.

I'm not sure what you're talking about here in regards to your distributor cap? Two caps on your distributor? What does that mean? Do you have a picture or something that will help to explain what you're on about?!

I had a problem like this once. I found that the wires that connected to the ballast resistor were a little corroded and loose. Cleaned them all up and crimped the insulated end of the wire a little to improve the 'clamp' on the balast resistor electrical posts. The problem never returned. I guess the electrical connection was poor and caused the intermittent misfire that I was experiencing. Good luck, let us know how you get on mate.

Here's my exhaust.

Powergains .... 7 out of 10(felt a good power gain not as much as expected) NOTE : This is the Twice Pipes on my 280Z ... the install and fit and power will be different for a 240Z without a doubt.. since the setup was designed for a 240Z not a 280z Are you running headers with this setup? I looked at an earlier photo and it seemed that you're only running the stock exhaust manifold. If so, why did you leave it on without replacing them with headers? Cost? Could that be the reason why you didn't get the power improvements you were expecting? Why did you spend the money on a system that you felt wasn't designed for your car or engine size? Did you not consider just going to a good exhaust shop and asking them to build you an exhaust system you should have got in the first place? Sorry man, I don't want to sound like a PITA but I'm not convinced your convinced that you got what you paid for! So how would you sum up your experience and what would have done differently if you could have started over?

cool

[ATTACH]23773[/ATTACH] I hope you didn't leave your top radiator hose looking like that!