drzed

Thanks for the info DAW. The rods are 133mm 240Z 9mm rods. The Toyota rods seem like a good choice for an offset ground diesel stroker crank going back into the diesel block. 83mm + 2mm + 2mm = 87mm stroke? Sounds like a good start on a theoretical engine build eh!?! So I made a choice a couple of days ago and came up with the following: My pistons are actually 86.5mm so I gain a very small amount of compression from what I had previously calculated. I am keeping the block for a future project and using an early N42 block instead (for the supposedly better rigidity). I'm decking the block 0.030" and using a .6mm composite head gasket for about 0.040" piston to head clearance and 7.3:1 CR (just slightly less than stock). After ready the articles on the SDS website I'm looking forward to a low compression high boost engine. This should work well and allows me to use the P90 head I have and keep the balanced bottom end together. Thanks for all the replies (and the offer to take the pistons off my hands)

Wow! Those numbers would certainly work for me. Well I may revisit the calculator tonight with the numbers for the N42 and look at all my options. I just have a hard time not using those JE pistons when they are here and paid for. Thanks for the help Tim.

CR would be 7.8:1 with pistons 0 deck or 7.25:1 with them the way they are. Not really interested in keeping the pistons .045" down the hole even with the N series head - in my thinking the pistons should always be within .040" - .050" from the head surface (including gasket thickness). Does anyone here run a turbo engine with an N42 head and 25 - 30 lbs of boost? Any problems with cooling or detonation? I've been running the P90 and am very happy with it. It takes quite a bit of timing with pump gas and has no detonation at all. I can live with a lower compression ratio as the engine in the car now has the factory 7.4:1 and is working quite well.

I'm having a difficult time deciding how to proceed with the following project and am looking for advice. I acquired a problematic stroker engine a while back and am looking at trying to use it for a budget upgrade for my 260Z street/drag car. The engine has many good parts such as a knife edged diesel crank, 9mm rods (shot peened with ARP bolts), forged JE pistons (86mm w/floating pins), O ringed block, ported head, custom intake, custom turbo header, and many other things I'm forgetting right now. The problems were mostly oiling problems due to P.O. screwups and improper bearing installation and a poor combination of parts. I can fix the oiling problems easy enough (crank needs polishing, needs new bearings, cam and followers are garbage) but the pistons are the real problem. Somehow the P.O. managed to select pistons with a 20cc dish that end up .045" down the hole! This makes for non existent quench and horrible compression ratio (6.7:1 with my 51cc P90 head). So as I see it I have the following options: 1) Deck the block the .045" (losing the O rings) and go with a 1mm head gasket to improve quench and get back some compression (7.25:1) Has anyone decked the block this much before? Will I lose much rigidity? 2) Try to find some slightly longer rods (134mm or 135mm) to bring the pistons up to zero deck (or mill the pistons if they are out of the hole). I don't like this option as it will require rebalancing the assembly and the costs of rod prep - I haven't been able to find any rods of this dimension anyway. 3) Purchase the proper custom forged pistons (or maybe 87 or 88mm units) and machine the block and rebalance the assembly. Probably more money than I'm willing to spend right now. So I'm looking for suggestions. If I can't work it out I may just put the head, intake and header on my existing engine but I ended last racing season at 21 lbs of boost so I'm starting to worry that the factory cast pistons are going to fail if I push them any harder.

I've used the Precision Weatherstrip on the last two cars with the same results (hard to close doors) but you can't beat the price even if you don't use the door seals. I bought my last kit on ebay for about $185?? from this guy "truckpartsaz@cox.net" - he is a great guy to deal with! We had agreed to use USPS to ship as I am in Canada and UPS brokerage is way to expensive but his shipper screwed up and sent it UPS anyway. I when it arrived and I owed UPS an additional $50 or so I contacted him and he automatically sent me back the difference - no questions asked. Just wanted to let everyone know what a really good guy he is if you are looking for weatherstrip.

This is what I did to my late 260Z (almost the same as your car). Install your '81 turbo engine, trans, driveshaft, rear end and CV halfshafts. Buy the adaptors from Ross at Modern Motorsport to adapt your CV axels to your 280z stub axels. The only other expense might be the cost to shorten the 280ZX turbo driveshaft a wee bit - mine fit but it is very tight. What this will do is eliminate 4 of the U joints from the system and upgrade the other two to the larger 280ZX turbo size. I have run this way for the last 2 years without any problems.

Yes a direct swap but I believe the output shaft on the turbo trans is larger and requires use of the turbo driveshaft. The downside is that the 280zx driveshaft is longer than the one in your 280z. I got mine to fit in my 260z but it is almost bottoming out in the trans. The upside is that the U joints are larger and seem to take quite a bit of punishment. Also the turbo driveshaft is different on the diff end. Lastly the turbo trans has additional clutches and is even more bullet proof than the NA trans.

I don't think you can fit the 10" wide slicks without either running coil overs or flares. I run the 26/8.5/14's on my 260Z with stock suspension and stock rear fenders with the lips rolled - they just fit. I use the 14x7 Supra wheels as the offset is almost perfect. The slicks I use are old and well worn but they still seem to bite well enough for mid 11's. How fast do you plan to go?

Damn they have that wrong too - most of us Canadians are "Blue Bums" not "Red Bums"!!

I used to run 225/50/R15 BFG drag radials and the best traction was at 20 psi with a medium burn out. Good luck on the 11's

Hey "TheNeedForZ" - I have a great solution for your dilemma. Why don't you come over to my house in Langley, BC and give me $50 US for my 300 MAF so you can save on shipping and the hassle etc. - I'll even guarantee it works! Seriously, PM me if your interested and I'll give you details of what I have as I'm not exactly sure what your looking for. Thanks Mike

1970 - 1978 fenders are all the same so yes they will interchange. Many reproduction fenders are of poor quality and won't fit any of the cars properly without lots of work. In my opinion take the extra time or spend the extra money and find a set of factory fenders - you will be much happier in the end.

Thats better! Thanks a lot Dave!

Hey Norm - thanks for the map but how do I blow it up to a useable size without it getting grainy and unreadable?

The Holset sounds like a great idea - I'll be watching to see how you make out 73turbo240z. This could be a hot upgrade as lots of Dodge guys are upgrading to larger units. I believe the HX35 is even bigger than your HY35 as the HY35 was used on later 2nd gen auto trucks. Also there are lots of different specs for the Dodge Cummins turbos. (I tried to copy and paste this info here but I can't seem to figure it out). http://dodgeram.org/tech/dsl/FAQ/turbo_faq.htm As you can see the factory wastgate settings vary from 17 to 26 psi depending on the year and model. I have a 98 12valve 215hp diesel with a stock HX35. It will boost to 21 psi (on my guage) but my research shows that this unit is good for 30-35 psi with great reliability. Lots of potential here for us! Now for my question - does anyone have a source for compressor maps for Holsets? I tried finding one the other day with no luck at all.

I think you should find an earlier body, drop all your drivetrain in it and keep it! (Sorry buddy I couldn't help it - I just wanted to get one last dig in.)

I think the best bang for the buck has to be 70-78 Z cars. If you can fabricate a little and are a bit of a scrounge you can make these cars do almost anything! Now, having said this, I am finding that it is getting harder to do it on the cheap as these car get even older - a few years ago good parts cars were pretty cheap and lots of used speed parts could be had this way. Lately I've had a harder time finding good deals but they are still out there. My latest project (the 260Z in my signature) was a Washington State parts car that was just too good to part out. I cleaned it up and dropped in an '82 280zx turbo drivetrain with a junkyard turbo and intercooler. Added some custom piping and other fabbed up pcs and it now runs 11's and is still fairly streetable. All this for about $3000 CAN$ including the price of the car. At least it was $3000 until I decided that it was just a little rough looking for me so I decided to paint it - I have NOT perfected the cheap (or fast) paint job! Judging by how long it took and how much it cost I never will. I also like the suggestion above about the RX3's but older Mazda parts seem so hard to get here.

Ya I like the idea of sumping the early tank as well. I was thinking of getting it boiled out and welding a sump under the existing drain about the size of a small cake pan - approx. 1 litre in size (I might even use one of my wifes cake pans but don't say anything). Then I would plumb a 3/8" line in and out and weld another drain plug in the bottom of the pan. Should work perfect and allow me to run about 5 gals less fuel at the track.

First things first - there are no fuel injected 260Zs in North Americia - only 280Zs were injected. The tanks in 280Zs come in two very distinct shapes. 1975 and 1976 tanks are similar in shape to 240 and 260Z tanks and should be an easy swap (although I have never swapped one myself). 1977 and 1978 tanks are the "twinke" shaped tanks and would not fit without major modifications due to the loss of the full size spare tire well in the floor on the later cars. I don't know about the use of the stock tank for the twisties but for straight line you will be OK if you maintain at least 1/4 - 3/8 of a tank depending on the HP of your car and the amount of traction you have. I was fine running 1/4 of a tank in my 260Z (with a Walboro pump) until I bolted on a set of slicks - then I had to maintain at least 3/8 of a tank to avoid the horrible surge of launching and then running out of gas at the 60 ft mark.

I'm in Langley, BC. I've got lots of spare parts if your looking for anything. I still have about 25 parts cars but I'm thinning the herd daily - wife says "that mess has to go". I'm into meeting fellow local Hybidz members if someone wants to set something up. I'm sure that I could dig up a bunch of the original BC Z club members and have them dust off their Z's.

Six cylinder timing covers are all the same from 240z to 280zx including turbo. Diesel is taller like L20B (identified by two bolts close together by distributor hole instead of one for gas engines). Keep in mind that the dist. drive must match the dist. type you are going to use. Turbo 280zx vs non turbo Z. The drives are interchangable in the covers.

I run an APV (Absolute Pressure Valve) or blow off valve or whatever you want to call it. It is my only method of controlling boost pressure and it works fine for my application. My setup is part of an old BAE / Rayjay setup from the late 70's. The Rayjay turbo is an EE80 which is about equal to a T4 I believe. This method is both good and bad. It is very simple - has only one moving part and almost nothing to go wrong. Boost pressure is increased by changing springs (or shimming). I have no boost creep or other problems as some others with wastegates do. The bad part is as mentioned before - turbine speed could get out of control if the system is not sized appropriately. My Rayjay has a very large A/R of .80 It does not start to spool till over 3000RPM (under foot braking) and isn't all in till way over 4000 RPM. Driving down the road these numbers would be more like 3500 and 4500. It wouldn't be my first choice for a control but it will work just fine under certain conditions. My car is an auto and mostly used for drag racing and spirited street driving. I run an SDS so the "leaking air" isn't a problem. I've been running it for 1 1/2 years now and it really pulls hard - best run of 11.49@116.

I run 19 psi on a stock bottom end with 225 000 km on it. Put fresh bearings and rings in it and its ready to go. I'm sure that the first thing to go will be one of the factory cast pistons but so far so good. It's got 70 - 80 passes at the track and several thousand street miles on it. Last night it ran an 11.67 at 116 with a used set of slicks I picked up at the swap meeting last fall - traction is great! When it fails I'll let everyone know what it was. Next stop 21 psi.

Thanks Tony D I'm disappointed about the 5 spd trans gears but the Auto first gear may have some merit - 4.3 or 4.6 sounds real good to me. My drag radials are squirming at just the thought of it!

"So do you guys run with your foot on your brake when you are @ full boost :P" Why yes I do in fact every time I launch at the track !!! Seriously though the brake booster holds enough vacuum to operate the brakes while I am foot braking as long as I don't readjust my foot on the brake to inch the car ahead while under boost - then the brakes go to hell in a handbasket in a hurry.