Compression, Compression, Compression...... I would keep the compression down. You can make the all the power a stock block will handle with the nitrous. Compression around 10.5 would be a good target. This should add some life to the block, stock crank, and bearings. The lower compression will need a little extra on the exhaust as far as flow and duration. Lower compression is more sensative to exhaust flow since the larger chamber won't evacuate as efficiently and needs more scavanging to get the chamber properly evacuated. Your Stg2's will be a big plus. Make sure to get the pistons cut with the right valve reliefs for the STg 2 valves. They will clear Stg 1's easy if set up for 2's. I'm not saying that lower compression is the way to go to make the most power on a nitrous setup, but in your given application with the strength constraints of your block, it is the way to go. Also remember, you only have 4 head bolts holding the gasket. Even with the 5 bolt 2's, you can still have problems blowing them into the lifter galley. Just as Nitro71 did with his blower setup. Hey Sean, it looks like you have some competition(FCoolfraz3). 6.72 with a small 210 solid cam. :laugh:
Jeff... Yeah Im still not decided on the rod situation..whether or not to get aluminum or diff't pin size and whatnot...i'll try to get the wiseco's for the stock rod and go from there...fish
Rick... So should I O-ring the block and use copper headgaskets? I reckon I will get the 11:1 wiseco's for stock rod..about the pin you said to use a regular pin right,non tapered...so do I just use what comes with the wiseco's or a stock Buick pin? Ill also get the wiseco's with a lowered ring land like ya said,too.Thanks for the info again fellaz..fish
No Coppers. Go with a Cometic 4 layer gasket. Yes it will cost more for the gasket but it will seal better and will balance out when you consider machine work. Copper gaskets can be prone to water leaks that can be a pain to deal with. With Copper gaskets, you not only have to machine the block but you need to put a receiver groove in the head. Save yourself the trouble and just go with Cometic. It will probably end up being cheeper. On the piston pins, if you can get the Buick pin in a tappered version, do it. THey are a compromise of a heavy thick stock pins and lightweights. You could get away with the standard pin that come with the Weiscos. I use the Chevy size pin so getting a pin is not an issue. You could get the stock rod bushed to take a Chevy pin. Compression with a flattop having 10cc valve reliefs, 70cc chambers in the head, .040 gasket, piston flush with the deck will give you 11.58 comp. If you with the same setup and go with a piston that sits .020 in the hole, compression will drop to 11.04. I'm not sure if the Weisco your looking at has a dish or if you heads have been milled. Just don't go out of your way to raise your compression. For now just do the pistons and plan on getting the TA Sportsman rods later when you beef up the block. You just have to keep the rpm down with the Buick rods. Under 6200. Get a good balancer if you don't have one already then go get the rotating assembly balanced.
Cool rick ,just got off the phone with J Burek... Pistons,pins,and rings are on the way,I'll be using the pressed pins for now but I can always use the floating capabilities when I get good rods. the wiseco's come with the locks for floating pins. I like the look of the corteco gaskets,alot of modern gaskets are like that so it must work....just gotta tear it down to the block and get machine work started...fish
I hear Fel-pro has a head gasket out that has the stainless steel in it.Rick what do you think about fliping the jets on a Big shot and flowing at 7 Your right on the trouble on the work to lockwire the Block I have a Isky cutter i run copper i spray the headgasket with copper coat never had a water leak havent blown a head gasket. Burned some Pistons ou: What are you going to do Nitrous is not eazy to tune I no one thing i have been runing a Magnafuel pump 500 in the back of the car and two Regulators on a log one for the carb and one for the nitrous you are always fighting fuel pressure between the two of them. I think a one gallon cell is my next step i am going to put my old 220 BG pump and Regulator up in front where my battery use to be. There is a safety switch that is like a dial. I dont remember ho makes it
What did you get 4.350 wisecos if you did have pistons in your hand before they do anything on the bore. I would have them hone the block to the size that you need most pistons are under sized. Ho did you get them from. what did you pay.
Jeff... Pistons will be here next wk. Motor should be torn down by then and I can have them fitted then,might be a good idea to use deck plates,but dont know anyone around here whos got em.Jim Burek sold me the pistons,for a real good price I think,incl. rings pins and locks for floating pins. If i scored the hell out of a wall, Ive got 3 other blocks that I can use. What kinda combination you runnin jeff? how fast...ill be here all day (sick) so dont hold back...fish
At 7 psi fuel pressure, the math says you can swap the jets around. I would start at the base line jets and work up carefully and would start at 8psi. You can always take away fuel pressure. Once it's lean, its too late. :af: I would only recommend the higher pressure setup with a forward mounted fuel cell. Nitrous is easy to tune, don't let Jeff tease you. Your tune up can be right but if you try to push too much nitrous than the motor will take, bad things happen. You always need to go up one setting at a time. As you get closer to the saturation point, you generally will notice the same tune-up runs lean. If you don't get the mixture straight before you try to push more, when you put the next size up it will be melt down time. If you accept the fact that a motor will only take so much then you'll stay out of trouble. If you put another 75 HP of nitrous on top of what your spraying and the car slows down then that is your first sign. Try tuning it. if that doesn't work, back the nitrous jet back down and work on finding the bottle-neck that is restricting the air flow thru the motor. It could be cam, compression, port volume, exhaust undersized, too much cam overlap, ect. Fish, get a ARP main and head stud kit for your motor. Studs will clamp better and allow more threads to be in the block to disperse the load. You right Gary, in your case the plate is drilled differently for the fuel bar over the nitrous. What the plate flows and what the jet flows are two different things. BUT being the NOS follow a flat jetting curve, if anything you'll go rich as the jet size increases. NX plates are flowed for what they are jetted for. On a NOS plate I believe the holes are the same size on the two spray bars. Still you need to go in small steps with the jetting and pressure change.
Rick... Ive got head studs in it now,not the mains tho..might go on ahead and get that done.Do I need to have it line bored/honed when I stud the mains? On the plate thing about the bars....if you look Real close you will notice that the spray holes are directed ...fuel comes out the sides of the bar..horizontally and the nitrous fog shears it coming down thru it from above..the n2o bar is always on top of the fuel so it can put it into suspension.Think the same deal goes on in a fogger nozzle too. If you reverse it i reckon some funky stuff would happen :error: ...fish
