fl327 Posted January 18, 2002 Share Posted January 18, 2002 hey ive checked out ratsun with my friend kevin, who was the previous owner of my car and a good friend of mine, and he has come to the conclusion that he must have a big block in his z, therby ending out "jtr marathon conversion antics", because of the extended frame mods we will have to do to the car. ive seen a couple good looking bbc cars including that monster that auxilary posted, we are wondering how much cutting will be absolutely necessary to put the bbc in a 1970 240z and as much info as possible will be greatly appreciatd. the motor we are building for the project is a warm 396 and trans will probably be a super t10. all z owners with big blocks please report to the dance floor. Quote Link to comment Share on other sites More sharing options...
Guest RON JONES Posted January 19, 2002 Share Posted January 19, 2002 First things first,the 396 is not the way to go.If Your going to add all that weight,You have to go bigger.454 AT LEAST!Big block sounds nice,but You would be better off with a 406 SBC.More Cubes with out all the added weight.My Car has all the origanal sheet metal removed and has a custom frame.If You go back to Ratsun.com,ask Brad about doing the Big Block conversion with all the stock sheetmetal in place.His Car was a street drivin BBC Car when He first did the conversion.He can tell You a lot about whats involved. Quote Link to comment Share on other sites More sharing options...
Racin_Jason Posted January 19, 2002 Share Posted January 19, 2002 I second Rons words. With the parts available for the SBC these days, you can make a serious brut! A few things to consider in your choice between SB vs. BB are weight, cost, hassle, power (that YOUR car can use) and ingenuity needed for the install. BB's weigh on average 150-200lbs. more than SB's. BB speed parts cost a HELL OF ALOT more than SB parts. BB's can definately dish out more power due to more cubes (but a 396 isnt even worth it, i agree) but you have to be able to USE the power. A few frame stiffening mods and big tires are definately not gonna hook a stout BB. The car will have to literally be built around the engines dimensions and capabilities..and its gonna get tedious and very expensive. I dont mean to beat down your idea. On the contrary I would love to see another BB Z in our gang, but only if you are willing to go through the motions. I definately dont wanna see you guys start a project that you dont finish is all. Considering the 427 Gorilla SBC builds that are out there now, I just dont see the need for a BB in a Zcar unless you are truly going for the ultimate. You can make well over 500HP and even be streetable with these SB's today. Just make a list of the prices and the work involved with both build-ups and make an educated decision. I've been both the BB and SB route, and for a Z I think that a well built SB can be very excessive powerwise...without doing anything more than going standard JTR or Scarab. A couple that come to mind are 1fstZ and Darius. Which ever way you go I'm in your corner I've just been there and spent more than needed and don't want it to happen to you. Jason Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 19, 2002 Share Posted January 19, 2002 the guys have a good point here, for you to benefit from the power any engine ,sbc or bbc has in a Z-car which has over 500 hp its necessary to install a roll cage and a sub frame to chanel the power effectively to the rear wheels, otherwise much of the power is used twisting your frame and wasting energy torqueing your suspension , now personally a bbc engine can easily be built to far out power a small block simply because better flowing heads, larger bores and larger displacements with stronger parts are available!but they also have a point that a 500hp sbc is easier to build and easier to install! Quote Link to comment Share on other sites More sharing options...
jap tin Posted January 19, 2002 Share Posted January 19, 2002 As long as your talking BIG block you might as well go BIG. Any more a 540 is concidered average displacement. How about a 632 with a set of oval port big chiefs? The only way past the weight issue is to use an aluminum block and heads. Yea, a all aluminum 632 with a sheet metal intake ans a pair of dominators. NOW, thats a BIG BLOCK Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 19, 2002 Share Posted January 19, 2002 "As long as your talking BIG block you might as well go BIG. Any more a 540 is concidered average displacement,.... NOW, thats a BIG BLOCK " WRONG,WRONG! check out the model 1200 http://www.torque-eng.com/v_12s/modelsf.htm ADD quad turbos and stuff that in your Z-CAR and no ones will catch you on a strait run!! BTW look at the installation drawing for dimensions of the motor mounts or if you must stay with a bbc SAR 712 CU. IN. PONTIAC 1400 HP NA 4.840 BORE SPACING 4.625” BORE X 5.300” STROKE SAR/Donovan aluminum block featuring raised deck and +.400” raised cam, Pro-Series 5.300” 4340 internally balanced crankshaft, custom BME aluminum rods, SAR/BME pistons with taper-wall wrist pins, fully-ported SAR/Brodix Pontiac 14.5 degree aluminum head assemblies featuring Manley titanium valves, Jesel belt drive, SAR/T&D rocker system with one piece rocker bars, Crane roller camshaft and roller lifters, ATI balancer, SAR 2x4 sheetmetal intake manifold with linkage, two 1250 CFM dominators, Moroso four stage dry sump oiling system with SAR heater, MSD crank trigger ignition system, “Sonny’s” aluminum sheetmetal valve covers, Meziere electric water pump, CSI pro-series starter and SAR vacuum pump kit. $42,500.00 OPTIONS: *SAR 4.900 bore spacing $1,000.00 *SAR installed NOS fogger (+250 HP) $1,500.00 *SAR installed NOS 2 stage system (+450 HP) $2,200.00 ****706 cu. in. for Pro-Mod application 1325 HP +600 HP 2-stage NOS = 1925 HP 4.600 bore x 5.300 stroke $46,000.00 Quote Link to comment Share on other sites More sharing options...
Michael Posted January 21, 2002 Share Posted January 21, 2002 I have a big-block Z. Well, sort-of. Some old but reasonably illustrative pictures can be found on Pete Paraska's site; look under "Michael OL's big block Z". I said that I sort-of have a big block Z. That is because my engine is apart and won't come back together until a long, long session of soul-searching, book learning and hands-on trial and error. Why? Because, as the guys have already mentioned, big blocks are big potential but also big bucks and big effort. Yup, it's all big. I have a 454. 454 is the natural big block. A 632 all-aluminum jewel box is nice, but let's face it - for most folks, that's ridiculous. A 454, however, is ROUGHLY analogous to a 350. They're out there. They can be pulled from old cars bought cheaply. But they are much, much rarer than small blocks. My car was set up for a big block from the very start. Radical frame mods, firewall setback, and a tube frame connecting all four strut towers. It balances 51/49 with an all cast-iron BBC. Stock suspension. And even now, after over two years and extensive semi-professional assistance, I often wonder whether it wouldn't be easier to just get a 350 for the time being, and start driving the car rather than staring at it. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 21, 2002 Share Posted January 21, 2002 Michael stick with the big block, when your finished at least you will have something very special, lets face it sbc z-cars are far more common! now if you just want to drive it put a nearly stock rebuild on that 454 and drop it in, you will be able to drive it while you save up for the additional parts you realy want and even a stock bbc 454 will run well in a z-car! Quote Link to comment Share on other sites More sharing options...
Guest 1fastz Posted January 22, 2002 Share Posted January 22, 2002 <-- had absolutley no problems hooking a z with 750 rear wheel small block horses with no cage or subframe Of course the b pillars started to crack .. Quote Link to comment Share on other sites More sharing options...
fl327 Posted January 23, 2002 Author Share Posted January 23, 2002 I love my sbc car, but were set on big block power from the start, pretty good to go now my buddy just bought another 70 240z thats in good condition, we are going to drop in the 83 l28su motor and trans from the other 70(the one thats getting bb) into the cherry 240 and make it a nice stock car, and then we are going to start prep on the bbz( a dirt nasty street car), from listening the ron and mr. barkley weve decided our plan of action. thanx guyz. our mounting will be the front mounts from a bel air bbc conversion mount kit that uses the front mounts and hooks to the motor mounts, motor is mild 454 with a super t10 trans(we have them both already 454 is out of a tow truck and the super t10 has been in the family for a while and got donated to the cause by yours truly), projected being 425hp and 400lbs, with the potential for more once we dial everything in. ( frame is getting a cage subframes that goe through dash to the motor bay frame rails, hopefully that is all that it will need) the end result hopefully resembles a jtr conversion, and it not, oh well. .... time for new challenges fellas.. we were getting scared of cutting up the car too much and we are excited that we dont have to shred the fenderwells to make it fit, almost "resorted" to doing a late model ls1 t56 swap and even considered a couple of those big inch world products motors, but a big small block is not a big block no if ands or buts about it., Emails to mr. barkley helped talk us out of the small block conversion. nothing against the sbz, but its getting a little common and getting too easy. im going to stay sbc, but depending on how well this goes, i may be next, the Feezy.Leezy 427???? Max Scarab baby Max Skeeezy bay-bay... Quote Link to comment Share on other sites More sharing options...
Guest RON JONES Posted January 23, 2002 Share Posted January 23, 2002 I'm Glad You got to talk to Brad.He is the Man on BBC Street Z's.Also glad to here Your droping the 396,great motor in its day,but that was along time ago. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted January 23, 2002 Share Posted January 23, 2002 So your constant 'encouragement' to Kevin made him decide on the BBC, eh? Man, hope he has figured out the $$$$ and the time this is going to take. Good luck in helping him do it--I bet you & Matt will be the ones doing a ton of the work--oh well, free Thai food & beer for life. Davy Quote Link to comment Share on other sites More sharing options...
fl327 Posted January 23, 2002 Author Share Posted January 23, 2002 kevin is a unique individual, when deciding on which powerplant to put in his z, his own personal ethic came into play and i think you heard him talk about this at the dinner table "its the best of the best or i dont swap motors" when he says that what it means in term of the swap is that it boiled down to two motors in his mind: a big block and four speed or the ls1 and the t56 the ls1 and six speed combo would cost a whole lot more to do and you are dealing with a whole lot more variables in that swap which would make it cost a lot more, but you do get a state of the art v8 motor and the infamous double overdrive six speed. great. motor and trans alone would be at least 4500.00 and we would need a bunch more stuff.and its a small block.... kevin was about to do it before we found out that all the cutting was not neccessary! big block country here we come, team maximum scarab(until we come up with a different name for our crew) baby. Quote Link to comment Share on other sites More sharing options...
Cable Posted October 17, 2007 Share Posted October 17, 2007 Late to check in, but I have a big block Z car. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted October 17, 2007 Share Posted October 17, 2007 wow...I thought Len was back Quote Link to comment Share on other sites More sharing options...
Pyro Posted October 19, 2007 Share Posted October 19, 2007 general run is... light car does better with a small block heavy car does better with a big block Takes a lot of work on the valve train to get a bbc to rev. Their valve trains are very heavy and takes lot of spring pressure which quickly wears out cams, rockers, lifters, and valve guides. Takes a lot of expensive parts to ligthen the valve train on a BBC. A SBC can easily rev to 7000 rpm with a stout flat tappet cam with a moderate amount of spring pressure. A LS1 with some head work and a moderatly sized cam can easily make 500hp. Does even better with a intake and carb. Quote Link to comment Share on other sites More sharing options...
Cable Posted October 19, 2007 Share Posted October 19, 2007 general run is... light car does better with a small block heavy car does better with a big block In terms of what? If you mean drag racing you are wrong. Any drag racing car will do better with the higher horsepower/torque engine, regardless of big or small block. Takes a lot of work on the valve train to get a bbc to rev. Their valve trains are very heavy and takes lot of spring pressure which quickly wears out cams, rockers, lifters, and valve guides. Takes a lot of expensive parts to ligthen the valve train on a BBC. Geez, you must really believe everything you read. While it is true that BBC require a bit more spring pressure to maintain valve control, its nothing crazy. Same goes for the cam and lifters, unless you are speaking of solid roller which all high rev, high horsepower engines will kill with time, regardless of BBC or SBC. Valve guides? Are you serious? BBC's have huge valve guides in both diameter and length. Even in stock form BBC valve guides last light years longer than SBC's. Bottom line, if you have the correct quality parts on a properly built street/strip BBC, they will last every bit as long as a SBC, if not longer because a BBC doesn't have to work as hard if they are making the same power (hence easier on parts). A SBC can easily rev to 7000 rpm with a stout flat tappet cam with a moderate amount of spring pressure. ANY SBC or BBC revving to 7000 needs more than just a solid flat tappet cam and decent spring pressure to live. Again, if both are built with same quality of parts like forged crank, decent rods, and forged pistons, etc...either with happily rev to 7000. A LS1 with some head work and a moderatly sized cam can easily make 500hp. As long as you mean the LS series of engines, I will agree for the most part. Although it takes more than a cam and a head porter to get 500+ ponies from an otherwise stock 5.7 litre LS1. Think about it, a stock LS7 with 7.0 litres is making 500+ and it has way better heads stock than the best ported factory LS1 heads. Even the magazine built-ups with their inflated numbers need a 6.0 block and HUGE heads to breech 500 HP. Does even better with a intake and carb. While it is true you can get better DYNO numbers with a carb on a LS series engine, I seriously doubt in the real world that the properly tuned and sized EFI will be bested by the intake/carb combo. Quote Link to comment Share on other sites More sharing options...
ron adams Posted October 20, 2007 Share Posted October 20, 2007 A regular Z is fun, sbc Z's are a blast but a BBC Z makes people have an involuntary reaction. I am reaching completion on mine and am excited to finally drive it. Quote Link to comment Share on other sites More sharing options...
Cable Posted October 20, 2007 Share Posted October 20, 2007 A regular Z is fun, sbc Z's are a blast but a BBC Z makes people have an involuntary reaction. I am reaching completion on mine and am excited to finally drive it. Oh yeah? Cool!! How did you mount it in your Z? Headers? I look forward to hearing back from you. Later. Quote Link to comment Share on other sites More sharing options...
ron adams Posted October 22, 2007 Share Posted October 22, 2007 motor mounts are from heidt's rod shop, headers are custom fenderwell to sidepipe headers. I spent six months of spare time measuring and routing the headers. I recently had the headers hot-jet coated. This project has evolved alot since I started. Quote Link to comment Share on other sites More sharing options...
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