byunique

I used to have that setup from Motorsport on my stock 240 about 15 + years ago. It was a cool upgrade, but limiting for exhaust flow. Sounds good/ different too as you can guess. Fine for a mild or stock motor, I would think it would definetly be a bit restrictive on a hotter motor.

So, I take back about what I said earlier...#4 looks like its a lot whiter than the others. So, it must have leaked in that area or the cylinder cracked for that piston. I forgot to mention it was burning white smoke the last time it was started, and LOTS of it.

(pistons) http://www.brandonyu.com/z/IMG_0035_1.jpg (head) http://www.brandonyu.com/z/IMG_0034_1.jpg

sorry, heres the head pics

Last weekend, I pulled the head off my Z in order to check out the head gasket. I have been losing coolant and the engine starting to get hot every time I drive the car for at least 20 minutes. After the 20 minutes, it seems the radiator is down a good gallon of water... (yeah, lots!!). I pretty much figured I had a bad head gasket. Unfortunately, when this first happened, I was coming home from the annual Motorsport Show in 06, and it was a small leak back then, where I would refill the radiator every hour or so, but it got to the point to where it is now, where I can't really drive it at all without having to worry about it losing too much water. Anyway, here's some more observations... After draining the oil, it came out sludgy brown color, and a sure sign that lots of water mixed in with the oil. The mixture was quite thin too, but still oily. I guess this is called emulsification, since the oil and water actually mixed!. The valve cover had tons of sludgy brown stuff in it as well, so know the upper valve train was affected as well. The head gasket didn't seem damaged as the naked eye can see. There wasn't a particular cylinder which showed it was affected. All the cylinder tops looked the same, as well as the plugs. I guess the head could have a crack in it as well, so will have that checked out. So, the leak has got to be a crack in the head or some gasket issue, but I just can't see where it's leaking. So, what about the bottom end? I'd bet theres a ton of sludge in the pan. When a thing likes this happens, is there a need to rebuild the bottom end or at least clean it up in some way? I can certainly pull the block, take off the pan and clean as best as I can. But, not sure if a situation like this warrants tearing it all down and having new bearings/rings put in... Thoughts on where else it could be leaking and is it necessary to rebuild the bottom end as well? I would rather not rebuild the bottom end if all necessary and get by with what I have for a while. I would like to build another motor in due time, but just not right now. (have to get ready for the Motosport Show again... Thanks Brandon

the jaws pic is pretty funny

The Motorsport Auto Show is a must see for everyone in San Diego/L.A area, so try and check that one out especially if you are new in the area. Coming at the end of April. I am coming from San Fran too!!

Yeah, its going to start sounding like a real sportscar, and to me that made the real difference between stock and Dynomax.... you will certainly like it the sound. I did a 2.5 inch straight back into the Dynomax and had a bunch of resonance around 3000rpms, it would certainly help with a center mufller to reduce that, and cut back the sound a bit...probably your best bet.

Glad I can share my experience with this EricB. The first time I really thought this would work is when I saw a car that Scott Performance had put together and it was at the Motorsport Show '05. It was a Cannon Manifold, but it was cut shorter, and thats what prompted me to do it. http://www.brandonyu.com/gallery/main.php?g2_view=core.ShowItem&g2_itemId=11813 I thought about cutting mine up, but it would be quite $$$ . So, I am really glad I found that manifold on Ebay. I don't think the short straight shot manifolds are plentiful.

I was looking for this answer myself, but I was motivated to check into it because of a stumbling issue I ran into as I increased the venturi size. For some background, my Mikuni 44's came with the Mikuni manifold, but I later changed it to a Cannon (long) manifold since I was told the long manifold makes more power. I never tried the Mikuni manifold, and just sold it on Ebay. My motor is a pretty built 2.8, 9/1 compression, large cam, ported heads and I love to see power above 6500 rpms. As I increased the venturi size to a 37 or larger I started to run into a big stumble if I accelerated hard, and that would be right off the line or punching it down the freeway. I could tell that my motor was getting lean at those moments, (per mixture meter..) and despite what changes I made to acceleration pump, jet size, etc. the issue was always there. It would be milder with 34's but would get worse with the 37's. Of course, this hurt my top-end power and I was always yearning to go to 39's but the stumble would be ridiculous at that size. So, I had asked around about manifold length and was told a shorter manifold would help, but was never told it would cure the problem. I hunted around on Ebay, and found a SK/Sanyo manifold which looked just like the long run Cannon (mine was 5.5 inches btw), but it was a lot shorter (3.5 inches I think). see pics of shape/size http://www.brandonyu.com/gallery/main.php?g2_view=core.ShowItem&g2_itemId=11681 After getting it setup, I was amayzed. The flat spots that I had disappeared, and there was a much tighter feel to the engine. It felt much more torquey all around. It ran great with the 37's and then I upped from 37's to 39's, and the high rpm range was extended further, but this time without ANY hesitation off the line or midrange. I can basically roll on acceleration off a stop light and smoke the tires all the way across the intersection and pull strongly to 7000rpm. (a 4.44 helps with this too ) Yes, this basically cured my car of the huge flatspot and I was able to bump my timing a few degrees as well w/o pinging. The engine is no longer lean upon acceleration I believe it has to do with the velocity of the charge due to the shorter length. I also noticed the manifold is cut at a higher angle so, it tilts up more the Cannon, which also may help per the previous comment about that. Yeah, a long manifold may be good generally, but didn't help in my case with larger venturies! The car is night and day different My advice is get something straight, but shorter than the standard 5.5" Cannnon.

Well, about that time again to see if my car is any faster.. Heading down to Infineon this Wed to drag my Z and see if its any speedier after I upgraded to a shorter intake manifold. Its opening day for Wed Night Drags. Please look for me and introduce yourself if you decide to have some Z comraderie at the track. Brandon http://www.infineonraceway.com/raceway_info/you_can_race/wednesday_night_drags/

Fiberglass holds it's shape better, and you will come to find out the urethane ones flex and actually move at highway speeds. After a while, the shape changes on the urethane ones and tends to sag a small bit. If you could brace it a bit, that would certainly help. i used to have one of their fiberglass ones and the tend to easily crack if you hit *anything*, like parking bumpers. For that reason, I would highly recommend going urethane. Also, air dams are truly functional, I remember how my Z used to float at 70mph, and became much more glued to the road after the airdam.

Fiberglass holds it's shape better, and you will come to find out the urethane ones flex and actually move at highway speeds. After a while, the shape changes on the urethane ones and tends to sag a small bit. If you could brace it a bit, that would certainly help. i used to have one of their fiberglass ones and the tend to easily crack if you hit *anything*, like parking bumpers. For that reason, I would highly recommend going urethane.

Video of cars leaving the Motorsport 2005 show. "MSA Sounds 2005" See the 800HP 240z take off, "literally take off..." downloaded mpeg1 file to your local machine (25megs) http://www.speakeasy.net/~brandon.yu

Yeah, Track days are the best. My two experience were at Las Vegas Motor Speedway in 2000 for the National Z car Convention and secondly at Laguna Seca. In Vegas it was blistering hot, 95 degreees F outside, and after a 1/2 dozen laps, I lossed by front brakes with a Porsche Boxter S breathing down my neck. I was having a great time holding him off to. Later on he mentioned that I was hard to catch. So, make sure your brakes are in great shape. I think only vented rotors with forced cooling would have helped me on a day like that!. When I was at Laguna Seca, my car was flagged down for being too loud and I didn't get my timed Solo 1 run in, so make sure where you are going there are no tight sound restrictions. Yeah, you can have some great time, just make sure your car is ready for it, otherwise it will ruin your day.!

Well, the best thing about the 240 is access, and this is no exception. All of the bellhousing bolts are quite easy to get to , and don't need any universal adapters or things like that. As far as the pilot bearing is concened, I would use every method possible w/o using a chisel to get it out. It's just too hit or miss, and you can easily nick the crankshaft this way. I did end up boring out the ID of the bearing, but it was very snug ,and didn't leave a bunch of slop in there. As far as my car setup. I will private message you directly, since I don't want to deter the original intent of this thread.

So, just wanted to share my lessons learned from doing this: 1) Impact Wrench: didn't take unloosen the flywheel bolts. Ended up taking a piece of pipe, drilling two holes in it and attaching it to the flywheel face... (using the holes from the clutch itself). The flywheel stayed in place by virtue of the pipe stopping on underside of the car body. Brillant idea as shared from members here on another post. 2) When removing the pilot bearing in the end of the crankshaft, I used a chisel, and nicked the inside of the crankshaft a bit. When pressing in the new pilot bearing, it was a bit tough to get in. The end of the bushing mushroomed a bit, ended up using a rotary to clean up the I.D of the bearing, since the clutch alignment tool wouldn't go it...yikes. 3) bought alll new parts, related to this job: clutch, throwout bearing, clutch collar, clutch master/slave, roller bearing. After pulling the clutch, found out that two of the pucks on the dual friction clutch was gone...yikes. Good thing I ordered a new dual friction clutch, since the old one was in there for 8 years, but was working good as far as I THOUGHT!!!. 2nd gear used to grind when shifting into it. Found out the clutch slave was thrashed. and most likely wasn't depressing the clutch all the way when shifting. It works like butter now...! 4) Everything was pretty straightforward on a flywheel swap other than this... Just be prepared to replace as many parts as possible. You don't want to have to do this twice. It's a one man job to drop the tranny, but certainly two to re-install it. Attaching the tranny to the engine is the hard part, just takes a bit of elbow grease and everything is in a akward position being underneath the car. 5) Installed a braided clutch line from MSA. The threads are longer than stock ones, so it looks a bit funny installing it. But just install it and don't worry..the nature of the threads keep leaks from happening. 6) Also, you should jack the car up pretty high in order to make clearance for removing the tranny. I don't have measurements, but the bell housing was larger than I remembered.

I just dropped in a lightwheight Flywheel, which I bought off Ebay. I had a shaved stock flywheel before, which weighed in at 16 lbs. The new one is billet Steel, 10.8 lbs (4.4kgs), made by Trust. It's working great and taking off 5 more lbs, was a worthwhile investment btw. Engine accelerates faster, and easier between gear changes... The only thing is, when I start the car, the starting sounds of flywheel sounds totally different from the stock cast iron flywheel. I do accept the fact that the difference in metals and the difference in mass itself is going to sound different, but just wanted to get opinions from anyone else who may have gone through this. When I speeak of the starting sound of the flywheel, I am referrring to the sound which results from the meshing of teeth between the starter and the flywheel itself. It sounds really metallic sounding, almost like grinding of teeth. It's hard to describe, but if you want you can download the wav file here. (186K, flywheel2.wav) http://www.brandonyu.com/z/flywheel2.wav When I first started the engine with it in, I was suspicious something was wrong, so I pulled out the starter looking for metal shavings on the starter teeth, but everything was clean. The starter itself sounds fine when starting de-tached from the flywheel. What do you guys think? Thanks.

If you are near Hawthorne, CA. Check out Pierre's Z. He's the guy that did the Restoration project for Nissan when they resold the Z car. He may sub it out, but he knows his stuff. I personally had my motor built by Contemporary Auto in Huntington Beach, CA. Although not specifically a Z specialist, a machinist/Engine Builder recommended by Motorsport Auto. Its a long lasting motor,..going on 10 years. Not sure whether he is still in business. Yes, Rebello Racing Engines is #1 as far as racing engines. "Extracting the most power for ITS racing" regulations.

Was that the fix?

Yeah, just did the same stainless clutch install last weekend. Same thing... threads too long. Will have to try the teflon tape.

Yeah, could be a bear of a job since the motor is still in the car. I will probably have to do some weird body contortions to get to it. What should I look for to decide whether it needs to be replaced or not? Thanks

Is there a easy way to remove it with hand tools?

Just bought a Trust Billet Steel Flywheel off Ebay. 10.8/lbs or 4.4kg, can't wait!

Have any idea of the rebuild costs for a 5 speed? assuming the sychro would be replaced?