Guest 4.3L 280z Posted December 28, 2004 Share Posted December 28, 2004 First off right now I've got a 4.3L in my 280z I finally drove it today, I had a 700r4 built with a shift kit and it spins the tires in 1st to 2nd and chirps them going into 3rd it was fun. I've never built a motor but I can usually do anything I put some time into. The motor I have is stock out of a 1991 s10 blazer and I need more power I can tell already. I also just want to get some experience so I'm going to find another 4.3 to build on. I was just wandering about any good books on building engines. I don't have a lot of money, I know where I can get a set of vortech heads with alluminum roller rockers for $200 does this sound good? And from what I understand I can use 350 connecting rods and pistons right? And is it definately necessary to bore the motor out if it doesn't have a lot of miles on it? Probably going to get the edelbrock cam that is supposed to match my 4bbl intake. I've already got headers made and a msd distributor on the motor in the car now, the custom headers were a birthday present so there isn't any way I'm going to switch to a 350, cause they weren't cheap. It should have 50/50 weight distribution anyway and I mainly want a good handling car. But do you all think I can get into the 13-14 second range with this settup? I haven't ran it at the strip yet, probably another week or so. ] Also how much power you think I'll need to beet my friends pretty much stock mustang? It runs 13.8. I need to woop his ass. Quote Link to comment Share on other sites More sharing options...
datsunlover Posted December 28, 2004 Share Posted December 28, 2004 Heh.. I think you'll be able to take him.. You've got a car that's 5-600 ponuds lighter than a Stang, and will have a better weight bias as well. I'll guess mid to low 13's are doable.. (seeing as stock Z's can do what... high 14's ? ) rear gear ratio and tires/traction will play a part though.. I think $200 is a good price for the heads and roller rockers.. and as far as I know, the 4.3 rods are the same as 350.. Im not 100% on that though. As for boring out, it depends on how bad the cyl walls are really.. You may be able to just hone them and re-ring the pistons (or pop in new pistons/rings.. depending on what you are doing..) and be good to go. I'd definatly run it once 'as is' to get an idea where you are, and where you have to get to.. I wish I'd run mine this past summer. Now I'll just have to go by the 'butt o meter' for how much power and acceleration I'm gaining from my cam/rebuild/diff change.. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted December 28, 2004 Share Posted December 28, 2004 The 4.3 is easily capable of 500 HP naturally aspirated. Chevrolet makes aluminum race heads, saw some on ebay the other day ported that went for $450 for the set. Standard 350 rods and pistons, that is correct. Look on ebay for some eagle, manley, or carillo 6 inch rods, even broken sets, they go cheap, pistons too. Vortec heads work well. Responds the same as a 350 to cam changes so choose cam patterns just like any SBC. The 93 and later 4.3's had balance shafts, stay away from those. If you have unlimited funds they make billet cranks for the 4.3 also. Something to ponder, oil in the combustion chamber contributes to detonation, ring seal is vital to optimum HP and TQ. Is it really worth it not to bore and hone with deck plates and mains torqued to get a really good round cylinder so you don't have oil consumption, smoke, and less than optimum power? I'm not saying it won't work just honing and putting some rings in, but why not do it right, make it last longer and run better than a half a#$ job. Quote Link to comment Share on other sites More sharing options...
Guest 4.3L 280z Posted December 29, 2004 Share Posted December 29, 2004 Thanks, do you all know any good books that will help me along so I don't make any stupid mistakes? Quote Link to comment Share on other sites More sharing options...
zliminator Posted January 1, 2005 Share Posted January 1, 2005 do you have any pics? are the mounts similar at all to the 350? Quote Link to comment Share on other sites More sharing options...
Guest Magnum Rockwilder Posted January 1, 2005 Share Posted January 1, 2005 The 4.3 is easily capable of 500 HP naturally aspirated. That's a bold claim. What are you basing it on? I "built" an imaginary balls-out 4.3 on Desktop Dyno and it put out 420HP/350TQ in full-on drag race form... unstreetable. With no changes aside from changing the 4.3 to a 350, the HP/TQ jumped to 580/475. That's a whole lotta "free" power(160HP and 125TQ), especially considering the 350 would be cheaper to build and easier to find a wide selection of parts for... and makes a lot more power in the low RPM so it requires less rear gear and would be more driveable. Do you have any links to 500hp 4.3's? I'd like to see just what it takes to get that kind of power from an N/A 4.3 V6. Quote Link to comment Share on other sites More sharing options...
Guest 4.3L 280z Posted January 2, 2005 Share Posted January 2, 2005 I just used the jtr style mounts, some people say it would sit to far forward but I thank its about right, easy to work on to. I'll post pics tomorrow maybe and I'll be weighing it soon. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted January 2, 2005 Share Posted January 2, 2005 Magnum what's your definition of streetable and how did you come up with that handle? My definition of streetable is way warped and completely unrealistic to most folks, but I want to live with no regrets and I built my first SBC at 14 years of age and I used silicone on the head gaskets cause I didn't know squat and I couldn't see how it would seal the water running from the block to the heads, but it worked anyway despite me. I don't think I mentioned that word streetable, I'm simply talking capability not practicality, and personal experience with 7 race v-6's on the dyno and on the track. I'm not sure what DD has for heads, probably really need an airflow file to get some good numbers but try pro ported wedge heads, solid roller.650 to .700 lift, 13 to 14 comp, single plane manifold, 800 cfm carb on alky and see what you come up with, then stroke it alittle and see what happens, pretty amazing. Play with carb selection, cam selection if you have some numbers cause they are the same as with any sbc. I'll dig through my records and see what combo's I have. It would be neat to see 4.3L 280z whip some v8 although I grant you he'll have to pack a lunch. Some circle track guys run them because of class, some because they get a weight break and probably more importantly because nobody claims the engines. Practicality doesn't seem to fit hybrid z's or it seems they wouldn't exist. Your entirely correct it is easier to achieve more HP with more cu in's, generally cheaper, but it isn't free, just available with more cubes like stroking and all of mine were stroked since I had to buy cranks anyway. 4.3L 280z is IMHO the purest essence of hybrid z, something different, unique in it's creator's own way. He's daring and my hat is off to him. And how did you come up with that handle? Quote Link to comment Share on other sites More sharing options...
Z-Dreamer Posted January 2, 2005 Share Posted January 2, 2005 I former member here use to run a carbed 4.3 and a ProCharger supercharger and it was nasty! His name is John Scott and he may still freqent this site. Do a search on John Scott and you may find a detailed description of his former Z. Mark Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted January 2, 2005 Share Posted January 2, 2005 Ok, checked the file, bow tie block, Sonny Bryant crank (3.75 stroke odd fire), 6 inch carillo's, JE pistons 13:1, Chevrolet Aluminum 18 degree heads CNC'd by Brodix. Custom roller from Crower, .704/.670, 800 holley by C&S, chevrolet race intake, made 523HP/440TQ peak numbers all NA. Quote Link to comment Share on other sites More sharing options...
Guest Magnum Rockwilder Posted January 2, 2005 Share Posted January 2, 2005 I just ran THAT combo on Desktop DYno and it pulled 550HP/420TQ. The major changes I made from my previous combo were 13:1 vs 11:1 CR, .704/.670 vs .550/.550, and the stroker crank vs a .060 overbore. Everything else stayed the same because i already had drag race heads, intake, and exhaust. So I see that you CAN make power with one if you go all-out, but I'm still unsure of why someone would choose one over a V8... the awe factor? I consider streetable something that can run for a long time without overheating, something that has a decent torque curve and can live with a <4.10 gear, and something that has a long life. My user name is a joke between my wife and I. We were trying to come up with "porn names" as a joke, and I chose "Magnum". I was trying to think of tough sounding last names, and I remembered that certain people in my home town called rottweiler dogs "rockwilders" and were deathly afraid of them, so I named myself Magnum Rockwilder. I told her I was going to legally change my name to that, but I settled for my online name. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted January 2, 2005 Share Posted January 2, 2005 Cool. Went to Manzanita racing IMCA and Late model. Ken Schrader (sp?) was there driving a "house" car for dirtworks. He did well and had 5 engines claimed by the end of the weekend all for $1000 each. Bet they lost over 50K in engines alone just to have fun. Quote Link to comment Share on other sites More sharing options...
Guest 4.3L 280z Posted January 3, 2005 Share Posted January 3, 2005 Well I raced him again and he hooked up good this time and it was about the same but I advanced the timing this time. I know he'll beat me at the drag strip a lot worse but I know I don't have near the power he does to. Looks like I'm not going to do the vortech heads untill after next semester in school due to lack of funds, cause I need the other "vortech" edelbrock intake. So I guess for now I'm just going to get one of the comp cam kits that come with new valve springs and maybe I'll find some L35 heads from the junkyard and have them shaved and ported, I think that'll be in my budget in another 3 weeks. Wish I'd of started with a v8 now but I got this motor next to nothing and it had already been rebuilt. Wish I could afford a centrifugal supercharger, I'd love to do a blow through carb settup but thats kinda out of the question. Oh well it could be worse. I could be driving a civic Quote Link to comment Share on other sites More sharing options...
Guest Magnum Rockwilder Posted January 3, 2005 Share Posted January 3, 2005 Nitrous. Cheap. Easy. Fast. Quote Link to comment Share on other sites More sharing options...
Guest 4.3L 280z Posted January 3, 2005 Share Posted January 3, 2005 I've been thinking going that route lately. I think I may add 75hp shot after the cam and I would like to get a LSD first just because I don't want to do one wheel burnouts at the drag strip and I think it will definately help out especially on wet days on the street. The only thing that worries me about nitrous is that I need this car to get me to school which is an hour drive one way for another two semesters. Quote Link to comment Share on other sites More sharing options...
John Scott Posted January 3, 2005 Share Posted January 3, 2005 Enjoy the 4.3 for what it is unless you have substantial funds. Its compact, reasonably powered, and unique. Comp cams will give you great custom grinds for a reasonable price. Later stock iron heads can be retro fitted with larger 2.02 valves and have a bit more potential. Ebay is a good source for the later aluminum heads, but make sure you get corresponding manifold as some were raised runner or other than 23 degree. Brodix used to make some as well. You can make a great street motor with bolt ons, but still not on par with a very streetable v8. Yes the 350 pistons are a direct swap, valvetrain, oil pump, external bolt ons, but not the rods unless you have an aftermarket oddfire crank. Really now, a NA 500 hp 4.3 will need thousands and thousands of $$ in custom crank, heads, valve train, rods, and most likely a stouter bowtie block. I'd be willing to bet total cost is double than the v8. Racing gas stations are hard to find on road trips, octane boosters are only band aids. .600-700 lift cams? Already been stated its used for commuting. I was walking the main caps on my stock block with 16 psi Procharger blowing through wimpy stock heads. Changing out main bearings every couple of thusand miles isn't fun. Four bolting will help, but again for the price of being unique you're going to pay. If you are set on 4.3 (still one of my favorite engines) and need hp check out the SycloneTyphoon sites for advice. Dollar for dollar you can build a turbo screamer that truely can be driven. Procharger is another great choice, it fits, especially using the JTR mounts, reliable until you get greedy with the boost. Good idea to go with forged pistons at least. Again, what I'm saying is you already have the engine, some bolt ons will surely help, but don't be suckered into thinking it will be a cheap venture to get much over 300 NA hp. There used to be a Miata drag car, 4.3 aluminum 8000rpm ex indy(?) engine. Tons of nitrous, 8 seconds 600+ hp finally melted a piston. Our old Drag Hybridz drag race hero Ron Jones knew him. John Quote Link to comment Share on other sites More sharing options...
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