halz

Here is a hypothetical question for anyone with some insight into carburetion and engine performance: Suppose I have an L24 engine which is in good working order with stock Hitachi SU-style carbs and a compression ratio of 8.76:1 (eg E88 head). Exhaust gas analysis and seat-of-the-pants tell me that the carbs are well tuned. If I then only change the compression ratio to 9.13:1 (eg E31 head) but make absolutely no other changes, will I need to adjust the mixture of the carbs? Possible answers: (a) Yes - richer. The new higer compression ratio will effectively mean each cylinder will generate proportionally more heat. A richer mixture will help cool the combustion chamber. ( Yes - leaner. The smaller combustion chamber volume at TDC will mean that the previous (low compresion) mixture will be too rich. © No. Correct mixture for low compression = correct mixture for high compression. Your thoughts ladies and gentlemen...?

...what's more, the ebay link doesn't even work!

Great potential in that car...for an original restoration. Please find a crappy non-original car to do your V8 swap.... or at least photograph this one extensively inside and out before you butcher it. As a matter of interest, does it have a tan or black interior?

And a vote from Australia!

1. Try Performance superlite style rims - they are made in Australia. http://www.performancewheels.com.au/super_lite_wheels.htm 2. Dashboard Restorations, a sponsor of this site and based in Queensland will be able to sort out your dash. http://www.dashboardrestorations.com.au/

Yep do that... then when you strip interior I can have the Tan parts!

Sorry, wrong engine to even think about asking for $18k....

A good point. Adjusting the valve clearances may also even up the relative cylinder compressions...but I'm not too worried about them

So I've had my Z for about 9 months now and in that time I've concentrated on fixing the major problems (radiator, bent wheel, oil leaks, crappy interior...) but last week it was time for the engine to get some attention. I took it to my local auto-shop and asked them to check the carbs, ignition and compression... Well it looks like I got lucky. The owner of the workshop loves older cars and is a fan of SU carbs! He balanced the carbs (they were way out) and topped up the dashpot oil (empty on both). He adjusted the dwell and advance of the distributor (again way out). He checked the compression (185, 195, 190 190 190,195psi) for my L24 with E31 head which is excellent. The car starts and idles very easily but has a slight hesitation on acceleration before pulling very smoothly and strongly. He noted the hesitation when he handed it back and asked me to return the car if I cannot live with it...the car is going back on Wednesday! All in all I am extremely happy - the engine was basically an unknown quantity and I was bracing myself for a big bill and a rebuild in the near future...but no longer! When the tune is sorted, I might consider replacing the muffler to get a better exhaust note...but that is probably all. (PS. all for $89.00!)

38psi in a 240z with 195 65s.

I've got 240.DAT DAT.240 had already gone (we're talking Western Australia here). I think that HS30 would be good...but probably a little obscure for non-Z prople.

Hey, I've just found a NOS console too...! I want to avoid the same problem and the person I know who has addressed this issue is "nr240". He made up a fairly simple bracket to support his choke lever...I saw the actual mounting the other month when I visited him but I'm sure he would have a photo if you pm him.

Ahhh, so my picture shows a "cold" problem not a "hot" problem. Does anyone know what a detonation-damaged head looks like? In light of Mike's point above, I imagine it would look like a shot-peened surface?

Sorry - its no.s 1 and 6 cylinders. And I can't believe its bad casting as the other cylinders are perfect... and wouldn't the head have failed a quality control check if it was like that when it was cast?

When I bought my Z the PO kindly included the original cylinder head and I took a close look at it for the first time on the weekend (see picture). A question: It this damage the result of detonation/pinging? If so, here are a couple of interesting observations: Firstly, the damage appears only in the chambers of no.1 and no.6 cylinders, not across all six. Secondly, the damage appears to be localized around the exhaust port in each chamber, presumably due to its greater relative heat. Has anyone observed similar? Are Zs susceptible to poor cooling around the no.1 and 6 cyclinders? Is this just a one off?

So thats the new FW04-2...!

Haaaaayyyy... who are you calling "Stagnant!" (kidding!)

here it is under the bonnet...

Right-oh...I've finally performed and tested Daniel's "hockey-stick" throttle modification and I can also confirm a significant improvement in throttle usability. It is now possible to sneak gently away from the lights and also to perform handbrake starts without wheelspin! (i'm going to miss those :devious:). Below are two pictures that show (1) an unmodified linkage alongside a modified (curved) one and (2) showing the new linkage in-situ... I made my new linage by bending and cutting to length the long linkage from a 280zx. I retained the threaded (ie adjustable) end and pressed on a socket cap on the other end after I had the desired shape. My main aim was to introduce a nice curve and leave some future adjustability for in the new part. The result is about an 85% improvement on the original setup...still not as good as a cable-operated system. I think I can further improve things by cleaning and lubricating all of the ball and socket joints in the whole assembly. I hope this helps other Z drivers overcome the problem too :classic: