I know the big block will make more power but I'm afraid the 320 heads will restrict the motor , sb 2 is limited in power because of the 2 center exhaust valves . Sb 2 is lighter . Should make 1200/1300 from sb2. 1600 BBC. Sb is 200 lbs lighter . Any thoughts ????
I like the looks of the sb2 and the "cool factor" but can build milder BBC and make more power. Worried about 320 heads. Being small.
any thoughts and advise would be greatly appreciated ...thank you
forgot to add . I have 225 pound precision injectors 90 millimeter throttle body for both motors . running on e 85 with no intercooler , thanks again for the time.
You are aiming low on your HP #s with that SB . It can make more power than that on E85 IMOP . That being said I would probably go with the big block as it will take less boost to make more power . If having it be easier on parts then the bbc is the way to go . And I am a sbc chevy guy but your goals need an engine that can go rounds pretty easy and the BBC is a better platform for doing that even though it weighs more than your SB2 engine .
alot of good advise here !!! thanks.......yes i would like to just use the 320's for now.. not sure how big a head to use and how much power i can make with the 320's verses a larger head same setup ???
Not sure that with the F2 HP is going to be a factor as much as the boost # you will need to make that HP. You will make plenty of power with the 320s, your engine just may use more hp to turn the blower and push the air through the cylinder head. If you were using an F3 it would be a bigger issue.
Does anyone think it would be harder for a boosted big block to find grudge races than a boosted small block. The BB alone might put you into a different class of competition. The BB will probably be more reliable and make more power but if you're really going to be looking for money races you might scare comparable competition.
If that sbc will rev and take it /you probably could run as good or better ets than the bbc.That weight off the nose is big to me.We did a 520 with 360 castings and they were ported to 390 cc area and it wasnt enough.If you keep those 320s.open up the cross sectional area in them as much as possible.Get the throat in the 92 percent area and get cross section in your intake correct.If you dont do that i think you willbe disappointed.jmo
Vinny
If I was grude racing... SB2 motor all the way! More RPM and more boost out of the same blower... put a BIG program in the SB2 castings and let it eat!
well since i posted the first time i have decided to go with the bbc. my 320 heads will have to do for now.....i looked more into using the SB2 motor and it seems after 1200 hp or so the center 2 valves being so close together give head gasket issues no matter how much water you get to them !!! i am going with the big block for now and starting to piece together a chevy small block 430 cid F3 splayed valve motor....with the exhaust ports symmetrical i can throw all the the power to them ...then i will be a few pounds lighter and throw the power to it !!!! i hope the 320 heads dont kill the power on my bbc for now
thanks for all the advise....i need all i can get, new to this side of the world
well since i posted the first time i have decided to go with the bbc. my 320 heads will have to do for now.....i looked more into using the SB2 motor and it seems after 1200 hp or so the center 2 valves being so close together give head gasket issues no matter how much water you get to them !!! i am going with the big block for now and starting to piece together a chevy small block 430 cid F3 splayed valve motor....with the exhaust ports symmetrical i can throw all the the power to them ...then i will be a few pounds lighter and throw the power to it !!!! i hope the 320 heads dont kill the power on my bbc for now
thanks for all the advise....i need all i can get, new to this side of the world
Sb2s definitely can work great with Prochargers. I know of a certain 400ci SB2.2 that never missed a beat with a F3 on it and went countless 6.70 and 6.80s @ 210+ at 3200lbs to win the NHRA Comp Eliminator championship a few years back. That had to have been in the 2200hp range.
WOW !!! that is good to know...i stayed away from the SB2 motor i had for fear of blowing head gaskets constantly . thanks for the info...maybe i will go that route in the bear future, i have all the stuff !!!!!!!!!!!
Im doing an SB2 right now that will make more then 1200. And the head gaskets are going to work. You just cant cool them like a regular sbc. You need to put the water in through the center exhaust ports and then pull out through the block. A guy in the turbo section made 1600 with a standard 23 degree head with standard exhaust ports. Just gotta modify the cooling system.
Car is beautiful whichever way you go, but dont turn away from the SB2 because of cooling, especially if you get a set of the edelbrock HIP castings
Im doing an SB2 right now that will make more then 1200. And the head gaskets are going to work. You just cant cool them like a regular sbc. You need to put the water in through the center exhaust ports and then pull out through the block. A guy in the turbo section made 1600 with a standard 23 degree head with standard exhaust ports. Just gotta modify the cooling system.
Car is beautiful whichever way you go, but dont turn away from the SB2 because of cooling, especially if you get a set of the edelbrock HIP castings
Exactly the focus needs to be on the head.The block doesnt have 8 places with 1200-1500 deg temps in it.Thats why i dont put water pumps on the block your pushing water through all those 90 degree angles.I push water into side of block and run a line into the center of head between ex ports.I drill angled holes from deck of head to get water up behind sparkplugs also.Nascar used to make extentions on water fitting going into sb2 heads to get water up between ex ports so it just didnt blow it back into the block.
Or you could put all the water into the head and pull it out through the block.
The head is not hotter because it is higher on the engine, its hotter because the exhaust gases are flowon through it, not flowin through the block. This has nothing to do with heat rising. Its pressurized. If you read my post on where the cold water goes first, you will see it is directed into the most critical areas first. Maybe ill dry a diagram.
Or you could put all the water into the head and pull it out through the block.
The head is not hotter because it is higher on the engine, its hotter because the exhaust gases are flowon through it, not flowin through the block. This has nothing to do with heat rising. Its pressurized. If you read my post on where the cold water goes first, you will see it is directed into the most critical areas first. Maybe ill dry a diagram.
I stated the exact same thing about heat with exhaust.You can pull the water out your block if you want to.I dont put a water pump on a block ever in my own deals and then i need # 12 lines going int block .Not room for that in the head.I have tried it everyway possible and have found putting water in middle of block is better than pump on block with all the 90 deg angles through pump front of block and front of head.I want the hot water out of head going to radiator first if radiator is being used.
I understand, im not running a pump on the block either. On an sb2 head there is room to put a -12 between the center exhaust ports.
My one disagreement with you is i want the coldest water possible going directly into the heads, where you want the water going into the block on the side first and then flowing through the deck into the head. Dont think there will be much of a difference, i just like my idea more lol. I will report back in acouple of months how it holds up around 1500HP
I understand, im not running a pump on the block either. On an sb2 head there is room to put a -12 between the center exhaust ports.
My one disagreement with you is i want the coldest water possible going directly into the heads, where you want the water going into the block on the side first and then flowing through the deck into the head. Dont think there will be much of a difference, i just like my idea more lol. I will report back in acouple of months how it holds up around 1500HP
I still run a line directly into head between the ex .ports also.I build engines for about everything and i have found some headers wont clear a 12 line.I dont run any pressure cap on my systems and use a trans cooler for a radiator.So i do see steam pockets in some scenarios.Its all good we have several 1500hp plus deals out there with no issues and im not going to change now.
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