DAW Posted April 24, 2005 Share Posted April 24, 2005 So I've been running my kids around to school, soccer practices, etc, etc, for a few years in my "mule," a which I adapted an N42 head to (10:1 c.r., gasoline fuel; 140mm rods, 83mm stroke, and other components). It runs fairly strong with a stock '78 efi/ECM analog mgmt system with minor tweaks and a header. I've heard it ping slightly only once and that was due to a bad tank of gas (always premium) and I'm seriously considerring converting to a low-pressure turbo (intercooled) and running the high static c.r. because I think that's the next best performance upgrade (rather than adding a bigger n.a. cam). The "sleeper" persona of the car would be better-suited to the quietness afforded by the turbo vs the resonance of the headers. I would start-out with a stock '82 L28ET ECCS engine mgmt system and L28ET injectors. I did this project with the sole intent of transferring the engine into a '72 240Z that's still waiting, but it has worked so well that I just started driving it when I took one of my other cars off the road for repairs/upgrades, etc., plus I've found there's still room for refining this project hybrid L6 engine before transfer. The other issue is the trans. Presently, I have the 3 spd A/T with lock-up convertor. However, the A/T with locking convertor and I have one of those to use but I'm not sure if the trans transfer is worth the trouble. BTW, if anyone is considerring doing what I've done, the a boss in the block used for a small oil drain to the pan that would easily convert to a dipstick for use with a rear/mid-sump pan to put the engine in an early Z-car; the earlier this boss. Why use an of an L28 block? For the same reason Nissan increased the block ht. of the L18 to that of the L20B they increased the stroke, it was either increase block ht or use a used a taller block. Once the compression hts of pistons have hit rock-bottom, there is no where else to go except to use a taller block. I guess I'm writing this to see if there's input re the choice to go with a low-pressure turbo at static 10:1 c.r. vs going with a performance cam. Given the ease of slapping on a turbo vs setting up a cam, I think I already know what I'll do, especially since it's auto trans. More specifically, what are the thoughts on using the cam when I convert to turbo, and am I correct in thinking I might want to drop the cam timing back from slightly advanced to stock or slightly retarded for turbo? Has anyone had experience with turbo-ing a 10:1 L6 -head engine, or is this new ground? DAW Quote Link to comment Share on other sites More sharing options...
Dnaught14 Posted April 24, 2005 Share Posted April 24, 2005 i suppose the better question to ask is, what kind of power you want to make and where you want to make it in your powerband. To me, high compression turbos are kinda silly, because you cant maximize the potential of a boosted engine that only allows you to have 7psi, and under 250rwhp. Equally with that high of compression, tunig on a turbo would be a task, and although it is relativly easy to slap on a turbo, you are going to run into bigger issues than you would doing a cam upgrade. My advise is to do the cam, or save up and do a stroker. You wont get as much as you would a turbo, but it saves you headache. If you want to go turbo, get an l28et with a p90, and boost the hell out of it. It all depends on what you want, do a search, there are people who have done it. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 24, 2005 Share Posted April 24, 2005 My experience with Volvo low pressure high compression turbos is that they burn valves. I worked for a dealer around the year when the 850t came out, so it could be that in the following years they got those problems under control. I don't understand how installing a turbo is easier than installing a cam, but then I've only installed cams and never a turbo. Low pressure turbo is an oxymoron as far as I'm concerned. You can get so much more from turning the boost up that it seems a waste to set it up so that from the get go you limit the boost severely. I love the engine build you've done, but why not save this one for the Z and slap a regular old run of the mill L28 turbo engine in the Maxima? You could then turn the boost up and potentially make a LOT more power than your 10:1 engine will at 5 or 6 psi, and you can save the engine that has all the work for the sports car. Yeah, it's gonna have lag off the line, it might not have the same throttle response, etc. But it started life as a diesel Maxima after all. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted April 25, 2005 Share Posted April 25, 2005 Just a thought, if you switch to a P79 or P90 head, that would drop your compression slightly to around 8.7:1 , and you would be able to turbo it w/o any high compression issues... Quote Link to comment Share on other sites More sharing options...
Guest DoTheDrew888 Posted April 25, 2005 Share Posted April 25, 2005 Sounds like you already have your mind made up about this one. Just peice a good turbo engine together out of the parts that you already have and go from there. Maybe you could even put a turbo cam in it and have both projects haha. Good luck with it though. Quote Link to comment Share on other sites More sharing options...
drzed Posted April 25, 2005 Share Posted April 25, 2005 DAW I've been following your engine combo with interest over the last while and am looking at building a similar engine for use with my 260Z. Have you ever sonic checked one of the blocks to see if you could safely bore it out to more than 86mm? If you build another did you plan on trying to use the diesel rods again (with custom pistons for those huge pins) or some other nissan rod? Sorry, I can't help you with your questions but I can add the following from experience. Once you go turbo you will never go back! Also if you are ever driving north and hour or two I'd like to meet up and see your combo. I'm just over the border in Langley. If you are looking for an excuse to come up we have a good 1/4 mile track (36 ft above sea level) with Street Legal Drags about every other Friday night. It would be cool to see the Maxima running down the track. Quote Link to comment Share on other sites More sharing options...
drzed Posted April 26, 2005 Share Posted April 26, 2005 DAW, come on up and we'll swap that diff! You don't really need to though as I drive out to the track with a loose convertor, a 3 spd auto (turbo 3N71B) and 3.90 gears on 24" tall tires - just takes a little longer. Besides when someone pulls up beside you at 55 MPH you can punch it and get three car lengths on them before they know whats happening! Thanks for the info. I have a line on two complete cars - one auto and one stick. Can't decide which but I'm leaning towards the stick as there is a chance that it might have some killer tall O/D ratio for use with my other car. Any preference? (I'm not sure of the years yet) I'm just interested in the block & crank as I want to use the rest of my existing combo as per my signature below. Quote Link to comment Share on other sites More sharing options...
Tony D Posted April 26, 2005 Share Posted April 26, 2005 The Maxima Tranny used identical transmission ratios in the Stick version, as did the petrol versions. I have a 275K mile Maxima Tranny in my wife's 260Z right now, and it had the same .7X O.D as the 82/83 N/A ZX cars did. The LD engine had a redline of 4600rpm (so I'm told) and most people have the "comfort level" of shifting in a passenger car around 3000rpms, so Nissan geared them identically. I was disappointed that the tranny and rear gears were not something spectacular---I was hoping I could use them on the Bonneville Car! The only place the gearing is different is that the Auto Tranny First Sun Cluster DOES have lower gears to move the car along. The gearing in that first hub IS different than the petrol versions of the Maxima. Theoretically when swapping to a petrol setup, it would let you come out the hole a bit harder, yet still retain the .67 OD of the 4 speed autobox for cruise. On a petrol powered car, that could mean a realiztic 4.3 or 4.6 gearset for off the line (if you can hook) and decent cruise economy for highway usage. Some things I noticed that were neat on the Std LD I dissected: Teh flywheel seems to be a dragracer's delight. Much heavier, and using the 240 style collar and pressure plate would allow it's use in petrol cars. Makes for speedshifting glory... I liked the D-Pumps Gilmer drive.... Looked at it for some time thinking of neat little crank driven accessories I could use that for, but...... And of course, there's the intake manifold... What hasn't been said about those huge runners! I was made aware that a turbo version of this engine was available in Europe, anyone happen to have any photos of that setup? Quote Link to comment Share on other sites More sharing options...
drzed Posted April 26, 2005 Share Posted April 26, 2005 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! Quote Link to comment Share on other sites More sharing options...
TABrinn Posted December 6, 2007 Share Posted December 6, 2007 I realize this is an old post but has there been any progress on the LD hybrid? Has it been fitted in the 240 yet? In another thread someone mentioned that it interferes with the hood. Would there be any differance in a 280Z? I love the idea of a high performance long rod stroker and am surprized not too many other people have attempted it. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 6, 2007 Share Posted December 6, 2007 DAW left us after getting in too many pissing matches. You might see if you can email him by clicking on his username, but I doubt he'll be seeing this post. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted January 7, 2009 Share Posted January 7, 2009 I thought I'd provide a bit of info about my SC'd LD28 block/crank petrol build. It is in that stage of pre-assembly. Yep, I'm using both the diesel block and crankshaft. Pistons are from JE. They are flat tops providing 8.5 cr. The head is a mechanical P90A. The basic work to date is as follows. Drilled and tapped oil feed holes in block to relocate pump pickup for the S30 oil pan. Bored block from 84.5mm to 85mm (That provides a nearly square engine). Drilled, tapped and plugged 8 steam holes in deck exposed with P90A head. Turned, polished and shortened (6mm) crankshaft. Shortening the crank is a common mod in Japan to reduce bad harmonics. Balanced L20B rods. Ported P90A. Drilled P90A to accept 12mm head bolts. Pre-assembly will be done to fit pistons and check for clearances to cylinder head/valves. Decking to minimize quench area to about 025 to 030. Fly cutting pistons to gain clearance and bring cr back to 8.5, if needed. That's it for now. There is much left to do and lots of small details. I'm still considering having a custom cam ground. I wish Ken Jones would provide me with specs based on his SC projects but I have been unsuccessful in that endeavor. Quote Link to comment Share on other sites More sharing options...
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