Guest DoTheDrew888 Posted March 17, 2005 Share Posted March 17, 2005 Ok, here is the setup that I will be building shortly. What I will be doing is rebuilding the engine. I am going to keep the N47 head and get it ported and polished. I bought a F54 engine with a P79 head and flattop pistons. I will be running the flattop pistons with the N47 head. I also bought a performance cam: .460 Lift and 270/280 duration. I have all the necessary parts to put it together so now im just waiting till I have time. Hopefully (if everything works out) I will have some headers ready to go on before I am done building. Exhaust system is currently 2.5" pipes, high flow cat, and dynomax muffler with stock exhaust manifold. Now for a few questions.... I was told that my compression with an N47 and flattops would be about 9.8:1 but I have read other places that it will be 10.4:1. First off, what is my compression ratio going to be? Second, will I be able to run on 91 octane gas with this setup? Also, How much is an estimated cost for a machine shop to port and polish the N47 head? Has anyone had this done? If so, how much did they charge? Lastly, I know that the F54 block is supposed to be better becaused of the siamesied cylinders but is it really THAT much better? I am probably going to use which ever block has the best cylinders (least amount of wear). Do you guys have any input on this? Thanks for all your help, -Andrew Quote Link to comment Share on other sites More sharing options...
Guest DoTheDrew888 Posted April 8, 2005 Share Posted April 8, 2005 What should I set my cam timing at?? Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted April 8, 2005 Share Posted April 8, 2005 I have that same exact build up! I had my F54 block bord over .20thou. I calculated my comression ratio at about 9.92:1 so I used an HKS head gasket its a 2mm head gasket that reduces my CR to 9.2:1 so I can use 91 oct. The F54 block is stronger but it wont make a difference on a NA engine ... it is a good Idea for turbo or 3.1 stroker engines but I don't think it would make any kind of difference on a NA engine. most important ballance your rotating mass. crank, rods, pistons, rings, flywheel, clutch plate, belt pully. It cost a little bit of money but it makes for a smooth high reving engine ... mine reves up to 7K easy, and Im running SU's. I still haven't dynoed the engine so I have no idea what the RWHP is but I did smoke a 2002 camero SS ... I think I scarred him when I "cherped" my tires in second gear:twisted:. Good luck with your build up and let me know if you have any questions. Rock on Z People Quote Link to comment Share on other sites More sharing options...
Guest DoTheDrew888 Posted April 8, 2005 Share Posted April 8, 2005 Did you set the cam timing at the stock location? I have heard from another person that I should set it there but I am just making sure. Thanks a lot. Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted April 9, 2005 Share Posted April 9, 2005 http://www.geocities.com/zgarage2001/rebuild.html LARRY Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted April 9, 2005 Share Posted April 9, 2005 yes stock timing seems to work great .... if you want to know if your two far advanced just put it in 5th at 20mph and floor it ... if it pings ... retard it... if not ... advance it till it does ping, then back it off till it doesn't thats your best timing about 12degrees I think Rock on Z people!~ Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 10, 2005 Share Posted April 10, 2005 I had a VERY similiar setup as well before I went turbo... F54 block, flat top pistons, N42 head (same as N47 but with square exhaust ports), used a stock head gasket, and compression was calculated to be 10.3:1. I also live in CA and ran on crappy california 91 octane. Originally when I built this motor it was in an '81 280zx, so I left the cam stock as I was worried it might not pass smog with any other cam. Also I was running stock EFI. Other bits were a 60mm throttle body, 3-2-1 header and mandrel 2.5" exhaust with free flow cat and muffler. That setup pinged BAD when I tried to run it on the stock EFI, and eventually I added an adjustable fuel pressure regulator and upped fuel pressure by about 10psi and the pinging went away. Unfortunately it ran kinda rich any time I WASNT flooring it, but it ran, and I drove it every day. That motor put 145hp to the rear wheels and 160ftlbs of torque. The most initial advance I could run was 8 degrees BTDC, 2 degrees retarded from stock. Any more than that and it would ping under heavy load, going up a hill or on hot days. Later I found my current 240z chassis and dropped that motor into the 240, but swapped out the EFI for a set of remanufactured Ztherapy SU carbs (with the richer running SM needles), and the stock cam was swapped out for a 480 lift 270 duration one. That setup NEVER had a problem with ping... not once. This could be in part due to the higher lift/duration cam giving a lower dynamic compression, or could have to do with the SU's, though even when I tuned them to the lean side, it never pinged, so I'm gonna say it was the cam that did it. I also ended up running 8 degrees BTDC on this one, any more advanced and the motor would diesel/run on sometimes after shutoff. Also, I found that I HAD to run the stock vacuum advance... I know a lot of people don't, but when I didn't, I would get odd bucking and backfiring problems regardless of how I tuned the carbs... once I hooked up the vacuum advance they all went away. By the way that motor made 170hp to the wheels at the same 160ft lbs of torque with the torque curve moved about 1500rpm higher than the first setup, thanks to the cam I'm sure Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 10, 2005 Share Posted April 10, 2005 I forgot to mention, that that motor was rebuilt, and the block was bored .060 over, giving me effectively a 2.9L motor. Also, an interesting little factlet, regarding the N/A to turbo transition... in it's current state, my turbo motor puts down almost double (about 90% increase) the amount of torque my N/A put down, yet only puts down about 40% more horsepower.... Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted April 10, 2005 Share Posted April 10, 2005 DAMN bastaad 525, I need your engine... I also have the engine run-on and I think im running 12 degrees advance timing. I'll try the 8 degrees... How much did it cost you to build up your turbo? did you use a stock ZX turbo setup and if so what kind of mods did you do to it (cause there's no way you left it stock .... it's not in our nature). I'm thinking about putting a turbo in my 240... I like my engine but I want that 300+ ft/LB of the magical torque:twisted:. rock on Z people! Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 10, 2005 Share Posted April 10, 2005 DAMN bastaad 525' date=' I need your engine... I also have the engine run-on and I think im running 12 degrees advance timing. I'll try the 8 degrees... How much did it cost you to build up your turbo? did you use a stock ZX turbo setup and if so what kind of mods did you do to it (cause there's no way you left it stock .... it's not in our nature). I'm thinking about putting a turbo in my 240... I like my engine but I want that 300+ ft/LB of the magical torque:twisted:. rock on Z people![/quote'] Hmmm it's hard for me to assess the cost of the turbo swap because I did a LOT of other work at the same time, I took the whole drivetrain from the ZXT donor car, not just the engine, as well I also took the radiator, as well as doing little bits like replacing all the oil seals on the engine while it was out... this was all done at once so the cost for me is a lot higher than if you were just doing a motor swap. Not to mention the engine I bought, though it performed well when tested for compression and was SUPPOSEDLY recently rebuilt, was actually on it's last legs and gave me a ton of problems soon afterwards and needed to be rebuilt. I CAN easily say though, that just buying a donor car and swapping in the drivetrain EASILY cost less than it cost me to rebuild and build up my N/A motor and get that installed... in the end though counting all the problems I've had I would say that the cost of each setup were actually VERY close to each other. I used to think that doing a turbo motor would be SO much more expensive but that really just is not the case. Quite the contrary, once you go turbo you can get much more return as far as hp-per-dollar-spent goes... spend the same to go faster. As it stands the engine, internally, is 100% to stock specification, just with the non-nissan rebuild parts (rings bearings etc.) but is not 'built up' at all. I'm running the stock turbo, stock EFI and just a couple extra bits like an I/C, BOV, boost controller and RRFPR. Then just upped the boost and that's it. I'm running a stock clutch with aftermarket, heavy duty pressure plate, and that's holding up just fine. About the run-on... if you're running SU carbs then timing is only one thing on a list of things that can cause run on. If they are older SU's, stock ones, they may be worn and leaking at the throttle shafts, or really, there could be like 10 other things that could cause run-on... including but not limited to: timing too advanced, timing too retarded, running too rich, running too lean, too-hot range spark plugs, vacuum leaks, improperly set cam timing, 'rough spots', sharp 'flash' edges or other possible 'hot spots' present in the combustion chamber, which can also include damaged or misaligned head gaskets, idle set too high, too much carbon built up in the cylinders... any or all of those things can be possible causes, and believe me brother I looked at just about all of them before I got it to stop by simply retarding timing a bit... Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted April 10, 2005 Share Posted April 10, 2005 thanks for the info Bastaad, What is an RRFPR , also what is a BOV boost controller and what kind of intercooler are you using. Are you running the T5 with the 4.90 rearend. what kind of 0-60 times are you getting are you getting? I totally jonesing for a turbo build up now... damn that horse power drug! Rock on Z people! Matt- P.S. I have the Just S.Us dvd from Z therapy, and I pretty much checked all the other stuff you said so timming is the onlyl thing left... I hope! Quote Link to comment Share on other sites More sharing options...
PUSHER Posted April 10, 2005 Share Posted April 10, 2005 What is an RRFPR , also what is a BOV boost controller Im guessing rising rate fuel pressure regulator, ups how much fuel pressure there is as boost goes up. BOV=blow off valve. Boost controller controls max boost. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 10, 2005 Share Posted April 10, 2005 yep just as pusher said... RRFPR is a fuel pressure regulator that can be set to add a LOT of extra fuel pressure when boost comes on only, effectively increasing the flow rate of the stock injectors, and allowing me to safely run 13psi w/o going lean some call it a bandaid, but it works fine for me and I'm very happy with it. Pusher nailed the BOV and boost controller for you. My intercooler is a Trust brand (the name Greddy does business by in Japan) and is relatively small, I got it for free from a pile of discarded policed evidence at the impound yard where I work. I'm not running the T5, rather, just a regular Nissan 5 speed trans with an open 3.54 R200 diff. Estimated 0-60 time, based on the HP at the wheels and the cars weight (~2400 lbs) should be right at about 5 seconds flat, maybe a little faster with good tires and a great launch. 1/4 mile time should be a mid-to-low 13 seconds, 13 flat or even a high 12 with good tires and a great launch. You're looking at the wrong car though dude... my car is relatively mild as far as turbo swaps go, being mostly stock... a LOT of guys on here have turbo swapped Z's that would make my car look like it was standing still.... Quote Link to comment Share on other sites More sharing options...
ww Posted April 11, 2005 Share Posted April 11, 2005 I was told that my compression with an N47 and flattops would be about 9.8:1 but I have read other places that it will be 10.4:1. First off, what is my compression ratio going to be? Second, will I be able to run on 91 octane gas with this setup? You're getting different answers because people have bored their motors out to different degrees. Same style (dish/flat) pistons, same head will give you different compression ratios based on bore size. ie. 86mm standard bore with flat tops and an N47 should give you 9.8:1 compression. Boring it out to 89mm will give you 10.36:1 compression. I assume that's where the 10.4:1 came from. With the larger bore, you're squishing more air fuel mixture into the head for combustion giving you more compression. Quote Link to comment Share on other sites More sharing options...
Guest DoTheDrew888 Posted April 11, 2005 Share Posted April 11, 2005 So do you guys have any horsepower and torque estimates?? I will be dynoing the car soon after the engine gets worked in so Im trying to get an idea of what to expect. I got some Monza headers to finish off the exhaust side so that should help a little. Im not really sure what to look forward to though, Ive heard estimates ranging from 180 rwhp - 230 rwhp. Haven't gotten any real torgue estimates though. Let me know what you guys think and I will post dyno sheets with in the next couple weeks. Quote Link to comment Share on other sites More sharing options...
ww Posted April 11, 2005 Share Posted April 11, 2005 Based on your description and depending on the quality of the head work, I'd guess somewhere in the neighborhood of 170 to 180 whp and 140 to 150 wtq Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted April 11, 2005 Share Posted April 11, 2005 Bastaad, Your eninge is EXACTLY what im looking for. I want an everyday driver that can smoke a G35 or most production "sports cars" I also want porche and vett owners to learn a little more respect. But I don't what some monster scarry fast 490 rwhp twin turbo death trap. I just want a moderate turbo that gives me an easy 230 - 250 RWHP. And your build sounds perfect. What body do you have 240 or 280? if its a 240 did you swap out the gas tank? I also have the 3:54 but its an R180 with the 280z 5 speed. As for your breaks, do the toyota 4x4 truck swap... cheep, easy, and your call will stop on a dime... mine does. I think napa sells the toyota calipers with pads for $50 each. The only mod nessary with the break swap is to trim the dust plate (or just take it off). Let me know if you have any questions on that. Rock on Z people Matt- Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 12, 2005 Share Posted April 12, 2005 So do you guys have any horsepower and torque estimates?? I will be dynoing the car soon after the engine gets worked in so Im trying to get an idea of what to expect. I got some Monza headers to finish off the exhaust side so that should help a little. Im not really sure what to look forward to though, Ive heard estimates ranging from 180 rwhp - 230 rwhp. Haven't gotten any real torgue estimates though. Let me know what you guys think and I will post dyno sheets with in the next couple weeks. I just gave you an estimate dude, didn't you read my first post? my setup (which was very close to the setup you're doing, details in my first reply in this thread) put down 170rwhp and 160ft lbs of torque, it was 10.3:1 compression because of the larger bore (.060 over). You're running less displacement and less compression, BUT my head was stock with only VERY minor polishing, no porting, so you should make very similar or possibly slightly more power. I wouldn't count on more than 180rwhp though, 230 is WAY too high to expect, don't set yourself up for a let down. Well wait I didn't see one thing, what are you running for induction? SU's? EFI? this will make a big difference as well, especially if you're running tripples, then you MIGHT get 200+ hp to the wheels. Bastaad, Your eninge is EXACTLY what im looking for. I want an everyday driver that can smoke a G35 or most production "sports cars" I also want porche and vett owners to learn a little more respect. But I don't what some monster scarry fast 490 rwhp twin turbo death trap. I just want a moderate turbo that gives me an easy 230 - 250 RWHP. And your build sounds perfect. What body do you have 240 or 280? if its a 240 did you swap out the gas tank? I also have the 3:54 but its an R180 with the 280z 5 speed. As for your breaks, do the toyota 4x4 truck swap... cheep, easy, and your call will stop on a dime... mine does. I think napa sells the toyota calipers with pads for $50 each. The only mod nessary with the break swap is to trim the dust plate (or just take it off). Let me know if you have any questions on that. Heh... G35 can smoke one of those EASILY. I just took down a '99 Mustang Cobra yesterday, I mean I MAULED him, raced him twice, first time I got a small jump on him and won by about 4 car lenghts by 80mph, second time HE got the jump on me, about a 1 car length head start, AND I bogged bad on the launch, and was a car length ahead by 80mph and pulling away fast. That's a 300 something HP car (supposed to be 320hp but apparently they often put down less power than they were rated for, like 260hp at the wheels though, more than a G35 that's for sure ). Now Vettes and Porches are another story. I did once race a C5 Vette, not the Z06 of course and it was very, VERY close, almost nose and nose but he was pulling away from me every so slightly, this was going up a freeway onramp. Porches... well... I can take out a Boxter S dunno about 911's or Carerra's or whatever. Best victory for me was a new Mitsu Evo though I think I'd not have won by so much except for the guy didn't seem to launch it to well, from what I hear they are not easy to launch well at all. Of course my setup is still very mild, I could squeez a couple more PSI of boost safely if I wanted to but dont know the condition or age of the turbo so want to take it easy... can't afford any major work right now. It's in a '72 240 body. And yeah upgraded brakes have always been on my list but I haven't had the means or the time to do any work on the car for quite some time. So the Toyota upgrade just bolts right up? Just trim the dust shield and that's it??? I thought there was more to it than that.... Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted April 12, 2005 Share Posted April 12, 2005 Hey Bastaad, the toyota break upgrade is the easyest mod you can do on a Z. all you need is toyota 4x4 1982 - 1984 calipers. the company that made the toyota breaks made the breaks for the 240Z and they just used the same exact design as the 240 but a little bigger and 4 piston. they litterally just bolt right up to the 240! The only "mod" is that pesky dust plate... I just used a sawzall and it cut through that plate like butter. a good tip would be to replace your break lines (braided stainless if you have the $100) you will also need new hard lines but thoes are like $5 for both sides, I just got 2 straight hard lines and bent them myself. Don't forget to turn your rotors, makes for a nice smooth stop. huge stopping power with the new breaks, think about it thoes breaks are suposed to stop a 4000lb truck. If you wanna get crazy with the break job you can get new vented rotors from MSA for about $85 a side. After I did mine I couldn't believe how great my Z could stop. check out this site for more info. www.zcarcreations.com/howto/caliperpage.htm the site mentions something about a 1/8" spacer needed to clear the rims I have stock 82 zx rims on my z and I didn't need a spacer. One more thing did you have to change the gas tank out of your 240 for your turbo engine? I've heard that the 240 tanks dont have "baffels" because they're not ment for FI. Any thoughts? Rock on Z people! Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 12, 2005 Share Posted April 12, 2005 heh see I thought it sounded easier that I remember... there's more to it than just bolting them on, but I guess not by much. Why do I ned new hardlines?? Different size or something? I don't have a sawzall or dremel or anything like that unfortunately the PRICE is definatley right though... another problem is that I've kinda been forbidden from working on my car in the parking garage of my apartment... so kinda limited on time and places to do the work. You have gotten me a lot more interested in this mod though... I figured it'd be at least a $300 mod (I think someone has quoted me $600 at some point, for parts and labor). By the way, which rims are the ones you have? I run stock ZX rims as well, off of an '81, they are the four pointed ones which I think are the ones commonly called 'swastika' rims? Also, what would the possible negative effects be of not running the dust shield at all? I notice on that link you gave the guy mentions you can just remove it. and sorry I forgot to answer you about the fuel tank thing, yes I am running the stock 240z fuel tank, and so far I've had NO problems with it at all. I do follow the one piece of advice given about it and that is to never let the fuel get below 1/4 tank, but then again, I've ALWAYS followed this 'rule' on every car I've ever owned, I've trained myself to see 1/4 as empty. If you let it get too low then yeah you could have a problem in a turn or hard accel/braking since there is no baffling, the fuel might uncover the pickup and the pump will suck air. I've driven the car pretty hard on twisty roads or whatever and never had a problem with it. You could always use a surge tank or have a sump welded onto the stock tank as well. I use the stock feed line, and am using one of the vent lines as my return line (about 1/4" line). Quote Link to comment Share on other sites More sharing options...
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