I have an 8ba I,m building for my modified and I have a question for the guys out there who have a lot more experience with them than me. I have two build scenarios here...... The entire valve train is getting done no matter what, everything new and a Serdi ground valve job on stainless undercut valves with a nice port job on both intake and exhaust sides. The block will be bored to 3 5/16" and decked. 1.... Flathead Jack rotating ***embly with Ross pistons and 4" crank. 2.... Ford 3 3/4" crank, stock 8ba rods and Ross pistons. The question is, How much difference will I see with the 4" crank, all other things being equal. I'll probably run an Isky 88 with two 94's and a Bubbas ignition. Help me out here guys!
you will have more low RPM "grunt" or torque....everything else being the same....the 4" crank is the way to go...nice choice of hardware !
The Merc is rated at about 20 HP more, but it feels like a lot more! Go the 4" crank before anything else.
If a "kit" is in the program you should just go directly to the 4.250" stroke, you will end up with about 150+HP @ 4300 and 250+ Torque @ 2200. This is with a somewhat "short" cam. You should be able to pick up the entire package, balanced, for around 1900.00, including the main set! Over here we prefer the Eagle crank (for ease of balancing), the **** rods (with the Pontiac journals) for ease of installation, and the Ross slugs! A 292" build works real well! Just dynoed one a short time ago! Some other options I would recommend are bronze guides, Teflon coated cam brgs, and "metric" rings which Ross can supply with their pieces. Thanks, Gary in N.Y. P.S. When looking for a shop to do the machine work I would strongly recommend asking about finish-honing the block with a block-plate to make for better ring seal! Especially at that 3.312" bore size.
That's the answer I was asking about. By going with the stroker kit I add about $1,000 to the cost of the build, ( rods and the misc. pieces that go with it, not just the crank). The car is worth about the same no matter which ***embly is in there, it's just the fun factor. My ***umption is reliabiility is about the same on both routes. Doing the motor in this fashion puts it into the "better" build area, and it should sound pretty good to boot. I don't think a Max1 or 400 is in the offering as I need to street drive this on a regular basis. The car itself is brutally light and with the '37 box and 3.78's in the rear with 31" tires it should be manageable on the road. If it's totally horrible I can always swith to 3.54's in the rear. I know the hot setup is to run the t-5 but it just wouldn't be the same. I'm going to use a pair of Mercury heads cut .010 more or less when I see where the deck comes in at. Like anything else, it's just how much you wanna' pay for toys. If it wouldn't make that big a difference I'd just keep the motor a 3 3/4" and put the bucks elsewhere. (I'd really like a vintage PM7, but that can wait). Thanks everybody!
Thought you guys might like this video.... http://www.youtube.com/watch?v=dYH1TgYhx84&feature=endscreen&NR=1 Almost as good as this one... http://www.youtube.com/watch?v=pvFaAhY1rhI&feature=endscreen&NR=1
You are doing all the right things. Good choice on the add on's. The one thing from my experience is they are choked on breathing. Your work on the porting will be a huge plus. With that being said unless you are really sold on "Stroking" the motor, the cam, intake, carbs and heads would and will wake these motors up. Plus with Bubba doing his magic on the dizzy will make the whole thing fire right. I have a couple of these running both scenarios. They pretty much sound the same. I actually prefer the stock crank set up with a good cam. I have run Schnieder's, Isky, and Clay Smith. I like the Isky as there is a greater variety on types. The 88 and Max 1 are my regular go too's for customer builds.
To 1950 Effie. Being mostly a Chevy guy I tend to like short stroke motors. Using the short stroke brings the motor closer to being "square". This usually results in a motor that winds up quicker. The longer stroke, at least in theory will give more torque and less rpm. My question is just how much better does the 4" stroke feel on the street? By the way, Love the pickup! As soon as I can make some time I'm building an older one to replace my new Ford. Reliable as hell but no fun!
Im starting to think an 8BA 3 3/4 crank, french rods, .125" Ross pistons, really well considered and extensive porting and 1.6 valves in a 99A block will yield the sweetest flatmotor for the bucks..closest to 'square' you can get really. if your car is really light, consider an aluminuim flywheel. My 32 roadster has a 99A with a stock bottom end, .030 over, well ported, twin edelbrock super, big exhaust . It screams. i love the way it winds up. Im not sure if that would only get better with more stroke and bore, maybe not. Im finishing up a 33 truck with a big inch ( 4" stroke 3 5/16" bore = 276) flatty in it, and it will be interesting to compare them..from the first drives it does feel like a stump puller, but that could be the gearing too..being a fresh motor for a customer, I havent wound it abouve about 3500 yet, but that feels about it.. my little 239 in the roadster is just getting going about then..hits 5000 easy and sounds amazing. I guess my answer would be..it might feel better, but maybe not $1000 better.
Well the stroker version has more umph. But it comes at some cost $$. I personally think that extra dough can be better spent on the cam, intake, carbs and heads. I tell that to each person I build one for. You have the porting part handled which really helps. These motors are asthmatic and really respond to help in breathing. If you wanted you can go up on compression with pistons. But there is such little room to work with it is really tight. Again, you can spend money on more sure fire proven methods. Don't get me wrong. I have motors done both ways. I still prefer being closer to square. I say...stay with that.
From the responses here and my discussions with all the old timers, (too bad my Dads not with us anymore, he'd know in a second!), I've decided to go with a 3 3/4 stroke, 3 5/16 bore combination. The RPM's are more important to me than the torque. I need to turn 5000 min. The car is so light, should come in at about 1,600 to 1,800 lbs., that the added RPM's will be more welcome. I'm going to use the Ross pistons and 8ba rods and have the whole thing, including the aluminum flywheel balanced to modern race specs. I'm also going to consider my cam choice carefully with the above goals in mind. I don't know is anybody has any experience with super 3/4 Potvin? Sounds like this could be the ideal cam for what I'm doing along with the Isky lifters and double springs. Everything else remains the same.
I ***ume you mean the 3/8 Potvin. It would be an excellent choice. Forget the adjustable lifters and double springs. We don't even use double springs in all out race engines. Modern spring technology has made them obsolete. Use the stock hollow steel lifters.
Pete1, By now I've figgered out to ditch the double springs. I have an old Ford valve ***embly tool that makes it a cinch to put the single springs together but I can't fit the ***embled valve setup in together and I have to ***emble the valves in place using my overhead valve compressor that I've welded a piece on for the flattys. I know the stock hollow lifters are much lighter. Is there any other reason not to use the Johnson style lifters? I've always ground a notch in my lifter bores to allow me to get the wrench in there really easy. I'm not totally new to flattys but most of my experience has been rebuilding stockers. This is my first really decent street build with a bit of performance.
Main reasons for not using adjustable lifters is, they are heavy and even though there are some that probably will hold setting, there is always the one that won't. "Heavy" equates to faster wear rate, shorter engine life and lower red line. Since you want to turn 5000+ you should be going for "light". You shouldn't be cutting notches,drilling holes or machining the tops off the lifter boss's to facilitate adjusting. You are reducing the area the lifter moves on and it is marginal to start with.
Point noted. I'm a little concerned with getting a good valve adjustment because I don't have a valve grinder to set my lash. I'll work through it.
You don't need a valve facer to adjust the valves if you have a lathe. Most lathes have a micrometer stop on the carriage and some kind of bracket to mount an indicator on the carriage. Use a carbide tool.
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