thrustnut

So whats wrong with the pistons? Nothin a vixin file and some sand paper can't fix!

A couple things to think about before turboing a car-make sure your cam is compatible with your turbo application, and I would not recommend using a P90 on an N/A with dished (stock) pistons, your CR will be pretty low. I have flats and am thinking about raising my CR, so you would be worse off then me. I would make a decision before you build on turbo or N/A and build accordingly.

Do a search and you'll find more info then you can use on the head topics. From the reading I have done the P90 with flat tops should yield low 9's-1 compression where as the N42 and NN47's with flat tops are in the mid 10's-1. I'm sure there are tons of variables, but this gives you an example. 10-1 is too much for a turbo, unless your only planing on only running a small amount of boost (IMO). The P90 is also the best flowing stock Nissan head out there.

So when you set your 30 deg. advance at 3000, do you just measure off the increments on your timing plate and fab a new one that extends positive? Would you just leave the vacuum advance disconnected? On the new ignition note, I would rather go with the MS system, I think it's 75.00 for the kit vs 300ish for the distributor. I will check my all in timing tomorrow and see where I'm at.

I just installed a larger cam in my Z and my manifold vacuum at idle is down in the 7-8 in hg. range now. I was wondering if this will affect the vacuum advance in the distributor. I'm not sure what the vacuum is when driving, or what the difference is between a stock cam and the larger one while at cruse. I have a 77 280 with the stock dizzy running into a Crane Cams hi-6R with TRC (TRC not hooked up at this time). I am thinking about mega-jolt or a mechanical advance dizzy, so any one out there with experience in this issue let me know. Chris

I have a P90, I want to up the compression with an N42 or N47. I want to see if running a smaller chamber changes performance noticeably. I am running an MSA stage 3 cam in my P90 with flat tops and wondering if im hurting myself with the lower compression. Just a test, a swap if I like it.

I would like to have an N42 or N47 head for a cam project I want to start. The problem is its around 60.00 to ship from your area to me in Oregon, so that cuts down what someone is willing to pay for it. 50.00 or so for one of the heads would be good for a local guy who could pick it up.

I turned down 5,000 back about 12 years ago. I think I would take the cash now. My buddy sold his tricked out CRX to a guy who just got his licence and the dude had it for less then a month before he wrapped it around a telephone pole.

SOLD...I always wanted a 300ZX TT, pretty sure I cold get one and mod it pretty well for 15K. Or do the responsable thing and pay off some debt....nah!

I know...diffrent application, I agree about swaping the fronts to disk. I just wanted to know if this was somthing actually done, or if it was one of the "I knew a guy who knew a guy who raced back in the day" things.

Wow...lots of info, thanks. My friend is thinking about auto crossing his 60-something Bug, which I think has steel drums all around. Sounds like for street applications and the occasional track day, swapping to disk would be a waste of time and money. Thanks John for all the inside info.

I would have traded my DD for that Volvo

I see how its an option, and someone with experience could pull it off, but when you install the cam upside down and are asking for help because your not sure what's wrong with it it would be best to stop and take it all apart and start over. If not because it would be "correct" but just to figure out what you did wrong and get it right for next time. I can just see someone installing the dizzy 180 out, the cam is almost 180 out and engine say 10 deg. ATDC...man, I would want a video! Anyway, yes I'm an A&P but I was a turbo-prop mechanic in the AF prior, and any time I did a job for the first time it was by the book...after you know what your doing you start cutting corners. I guess I still hold to that.

I'm not too worried about myself, I don't race at all and recently upgraded to the Toyota brakes in the front and want to see the improvement before doing any other brake changes...that is unless I can get ahold of a set of BRAAP's cool looking lines (in tuner red of cource). I just wanted to know if any one had ever herd of doing this, I figured with the nature of the site and the raceing backround here, it would be the place to ask. He said there's a guy that charges fifty or seventy five dollars per drum to drill them.

I was just talking to a buddy who's into VW Bugs and he was telling me that one of the "upgrades" they are doing for auto cross it drilling the drums to prevent gas build up under heavy breaking. He said that when tested the drilled drums produced results pretty close to a stock disk set up. Any one ever herd of doing this?

You might want to try gap filling lock-tite...I think its green. That might be too much gap though. I think it looks pretty good considering

I would like to know what the actual amount the government is spending per car in this program. You have the 4500.00, but then you have to destroy the car that's traded in, which costs money. So, does the dealership pay for the products and towing and dismantling and crushing ect... or are we picking up the tab for this? Any one out there know?

Hey man, thats your tax dollors at work!

I didden't miss it...just trying to figure out why you would do it

Ever thrown a soda bottle full of as in a fire? It doesn't blow up, as soon as the fire melts through the bottle it just uses the gas to to enlarge the flames, no explosion...at least thats how it happened when I was a kid doing it. That was a FULL bottle correct? Ever throw in one that only had a little fuel, mostly vapor? When I was in the AF we tried lighting JP-8 on fire (diesel/kerosene jet fuel). We found that a match in a full bucket did nothing, but if you threw a match in an almost empty bucket...you get the fire department

My thinking would be with a helicoil you have less chance of what just happened to you happening when you tighten the bolt down. Maybe with the coil in it will give the area around the repair a little more strength and make it less likely to break out. Not sure if the hole your talking about goes into a water jacket, I think some might. In that case you might want to seal the helicoil to the block. Take your time on this one, I don't think its a late night rush into it fix. You mess it up too bad and your out of options.

Allot of turbo applications on piston aircraft engines have the compressor aft, so I don't "think" you would have a problem. As stated before, maybe turbo lag because of the length of piping? The intake worries me, how will you filter it? My Z gets lots of leaves and stuff stuck under that cowl.

I'm running a 625 CFM Carter carb with probable the same pump with no regulator. I have a narrow band O2 to help get me in the ball park tunning wise and under full throttle I never had a lean problem. I'm not sure of the diffrences between tripples and a big 4BBL, but I have never leaned out under full throttle.

I don't know if drill and helicoil would work if the hole is off center. The only way to fix that IMO would be to up-size the hole to re-center it, then your talking drilling the cover as well, which would make me nervous, this is the block were talking about. Maybe fill, then re-drill, but you would want the weld pretty perfect (no voids) then drill, helicoil. Any of these options I would want the block right in front of me which would mean pulling it out of the car. This is a touchy repair, you want it right the first time. Pics would be nice, maybe its not that big a deal.

So how would installing the dizzy 180 out and leaving the cam to engine timing be less catastrophic? If you remove the rocker arms (as stated before) thus releasing the valves into the head, rotating the cam to the correct position (which will not move the valves because there's no arms) ensuring the cam to engine timing is correct. Everything that has to do with the timing on this car is incorrect, you try to install the dizzy 180 out and start the engine and I'm pretty sure it will be toast. If your already in there, just do it right. Cutting corners will cost you money.