Ok, it has been brought to my attention that the Bulldog block will start shipping out sometime around November. I called to talk to Jim today and he was out. Looking to get the final specs on the block. If the specs on the website are correct..... * 4.8 inch bore spacing which will allow up to a massive 4.6 inch bore. The bore spacing change was not a good idea. Now it will have a valve way to close to the cyclinder wall, which will kill flow. Connecting rods will not work, wrong off set. Receiving grooves in heads will no longer line up with O-rings in block. A Buick already has a huge bore, why does it need to be bigger. We need to quit trying to make it a BB Chevy. * Priority main bearing oiling system (the crank will get oil first!) * Massively increased main webbing and the use of steel 4 bolt main caps. * A solid lifter valley to eliminate lifter bore breakage and allow the use of optional larger diameter lifters.If I don't want this option stock lifters will work?? * More material in the cam journal area to allow use of custom larger diameter camshafts.So if I don't want this option a stock camshaft will work?? * Optional smaller diameter main bearing saddles to reduce crankshaft bearing speed and reduce friction. Less friction means more horsepower! * Additional head bolt bosses and holes for increased cylinder head sealing. Where are the additional head bolt bosses and how many? But pretty much if the first one is true at all the block is worthless to anyone who currently has a high dollar engine or bottom end. Unless you want to change half your parts. Rod
You got me to thinking so I did a little looking around and found out a stock 455 has 4.750 bore spacing. I did a quick drawing of a cylinder bank with 4.80 bore spacing with the cylinder walls thick enough to cause the walls to touch between the cylinders. I figured this as a minimum thickness since the cylinders are supposed to be siamesed. A 4.34 bore leaves a .225 wall thickness. I overlayed cylinders with a 4.750 bore spacing and 4.34 bore and these are the (approxamate) wall thicknesses if the 4.80 block was bored with 4.750 spacing; (.320 cyl 1 .140) (.260 cyl 2 .200) (.200 cyl 3 .260) (.140 cyl 4 .320) At worst (.140) this is the same wall thickness as a 4.5 bore on the 4.80 spacing. I guessed at wall thickness just to have a reference and really don't know how thick the walls will be, but it looks like boring the block using a 4.75 bore spacing may be doable, on paper anyway. And, this is assuming the head bolts are in the stock locations. I'm done frying my brain for now, time to snooze! :sleep:
You can order the block with any lifter size or cam tunnel and main size if you preorder the block the remainder of the blocks made on the first run that are not taken will be stock dimentions I beleive Jim is the one to ask. The bore center will only be .025 different per cylinder which will still be a problem with orings but I don't think it will be a problem with the rod offset I may be wrong. They designed the block to go big 540 plus thats why the big bore.If you don't want a big bore don't use it there will be plenty of cylinder wall thickness then.If you go to the bigger bore the will be less valve shrouding. Big block chevy's have a smaller bore 454's are 4.250 stock
My rods barely fit now. I don't think there is any room to move them left or right and still work. I could be wrong. I would have to buy new stuff and I've already got big $$ wrapped up in this. I don't see why the bore had to be messed with. 540+ is way more than needed, NHRA limit is 500 and they don't have a problem getting it to work. Just the fact that the o-rings won't line up is something that will count me out on this new block, unless I want to pay my guy big $ to off set the o-rings in the block. This new block seems to be a great thing for someone starting from scratch, it's not pratical for someone that already has parts. On the chevy thing I was talking about the after market block. These are just a few things I see some running into problems with, I could be wrong. Rod
I'm sure you could call Jim and have the block bored on a stock center line.I'm sure he'll work with you.I can't see you backing away from this with out seeeing what can be done.I wanted a few things different and they worked with me. Pro stocks run a 4.650-4.70 bore with a 3.60-3.70 stroke and turn 10k to do it.
Bore shift, o-rings On the bore shift that .025 it's from the center out, it's not progressive front to back so I can't see anything being that tight. Thats .025 shift on the 2 center pistons and the 2 outside would be .050" off from stock. What they shave off my BBC rod to work off the stock width rod journal would be more than what the block is shifted and I don't have any problems. I know a stroker is different but, come on, I can't see you not being able to make room for that small amount. If it hurts flow, it will hardly noticeable and only on the 1,2,7,8 pistons since 3,4,5,6 will actually give that .025 to the intake valve side. I think my TA heads had more valve shift that what the block will have in bore shift. I want to say that the shift in the block will help my heads since my intake valves were close on the center cylinders. On the o-rings, I would just fill the groove in the head and run Cometics. I haven't seen one high boosted v-8 yet where they haven't worked as good or better than a o-ringed copper gasket. The new block is designed for eveything to just swap over from stock. One thing, you wont need that main girdle, lifter girdle, hard block, or 13 qts of oil anymore. I wonder if that means the new block will total-weight out lighter than a beefed-up stock block??? Being able to open up the lifter bores and cam journal size is a big plus if you can afford it. :Brow: Smaller mains option!!! SWEET, Just a "turn" away on a forged crank. Now maybe I will be able to get oil to the rods without all that crazy oil pressure. 1/4 mile hear I come!!! :3gears: :beer
Personally I don't care if it's "turned into a Chevy".......HP is made when you can move air through the cylinders which is accomplished with RPM.......If anything,Right now we have too much stroke to make our CID which means overweight,power-robbing internals. Until you're willing to rev,You will be banging your head against the wall trying to do it on torque alone. Kevin is right about the specs on which NHRA Pro Stock arrives at 500CI and the make 1300+ HP.....But they use more cylinder head than we'll ever see.
Big Bores Not only do you have more weight with a longer stroke but more Hp eating drag from the piston and rings having to travel further.
Jim called me back yesterday. If things end up the way he is telling me,it will be pretty much stock with more meat. He will work with the guys that want the big bore, small main...ect. So, this should work out pretty good. I need to have Rod talk to him once they start pouring the final specs. I think we might take a road trip to Indy to check one out when they finish one.
