Wasser bitching
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- Posts: 389
- Joined: Sat Jan 04, 2003 12:01 am
Re: Wasser bitching
I think the volume of the dish in the QSCs (96mm) is 47cc. And the comp ratio with the 78 stroke will come out to 10.4 and 91-92 oct. fuel will work fine. I will double check from the downloaded pictures I have at the shop. I will repost if the above figures are not correct. Have you looked into getting better rings for the QSCs. I can help you if you want to replace them. If you have not replaced the ex. valves this is the time to do that. Did you talk with DPR about grinding the crank to tighten up the mains? Thanks Rocky
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- Joined: Tue Apr 25, 2006 8:13 am
Re: Wasser bitching
QSC dishes are 47-48cc, verified. Good pistons, very consistent dimensions, weights, and cylinder clearances, but I always use better rings than the ones supplied. Rocky can supply the right set.
These online calculators make short work of determining compression, but careful, they can be addictive for the engine dreamer:
http://www.not2fast.com/turbo/compressi ... sion.shtml
http://kb-silvolite.com/calc.php?action=comp
These online calculators make short work of determining compression, but careful, they can be addictive for the engine dreamer:
http://www.not2fast.com/turbo/compressi ... sion.shtml
http://kb-silvolite.com/calc.php?action=comp
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- Posts: 8
- Joined: Mon Oct 04, 2010 6:44 pm
Re: Wasser bitching
Oh yea, mains getting ground did some homework. Im going to check your sight and check into rings, Thanks Rocky and tencent. I don't want any problems when I get the crank back.
Been too long..... the guy who said it was expensive on the vangon was not kidding. Glad its coming together.
Ill start taking picks of my build did alot of work to this thing.
Got another motor torn down a chevy 5.7. After the 5.7, its old blower motor, rubber tubing, 8inch pipe and a distrubuter both from a old chevy and it's flamethrower time!!!! Every one here welds and steel, alum. is laying all over the island, we do not have recycling here...hehe I got a friend with a jet lathe and mill......and a plasma torch. It will give him the gleam in his eye. I wonder if I can pump propane into the tube??? Wonder about how our police will feel about my 4x4?
Im a single dad and in college for computer sys. tech., got time and getting grants.... Disabled and getting some school so I can afford these pet projects. 38 years old and relized I cant hump lumber or twist wrenches everyday. So its off to my next passion computers. Thanks guys will post you on builds and wet dreams..... ahhhh cars, I love them again... now I dont work on them everyday. Go figure???
Been too long..... the guy who said it was expensive on the vangon was not kidding. Glad its coming together.
Ill start taking picks of my build did alot of work to this thing.
Got another motor torn down a chevy 5.7. After the 5.7, its old blower motor, rubber tubing, 8inch pipe and a distrubuter both from a old chevy and it's flamethrower time!!!! Every one here welds and steel, alum. is laying all over the island, we do not have recycling here...hehe I got a friend with a jet lathe and mill......and a plasma torch. It will give him the gleam in his eye. I wonder if I can pump propane into the tube??? Wonder about how our police will feel about my 4x4?
Im a single dad and in college for computer sys. tech., got time and getting grants.... Disabled and getting some school so I can afford these pet projects. 38 years old and relized I cant hump lumber or twist wrenches everyday. So its off to my next passion computers. Thanks guys will post you on builds and wet dreams..... ahhhh cars, I love them again... now I dont work on them everyday. Go figure???
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- Posts: 8
- Joined: Mon Oct 04, 2010 6:44 pm
Re: Wasser bitching
I did the calculations for 96mm pistons, 78.4crank, 50 cc piston cup and 20cc heads and came up with 7.61 commpression. Is there a way to to talk to rocky? Ill check his sight for a phone number. The pistons with 76mm crank come up in cyl. to .070 with 78.4 crank, pistons would still be short, .022. I measured heads and pistons with ml syringe 50cc pistons and 20cc heads is right. Can someone double check my findings?
COMPRESSION RATIO CALCULATOR
Static and Dynamic Compression Ratio
(Considers Cam Timing and Rod Ratio)
ENTER YOUR DATA CALCULATED DATA
Cylinder Head Volume (cc) Cylinder Head Vol (cubic in.) 1.220
Piston Head Volume (cc) Piston Head Vol (cubic in.) 3.050
Gasket Thickness (in.) Swept Volume (cubic in.) 34.473
Gasket Bore (in.) T.D.C. Volume (cubic in.) 5.089
Cylinder Bore Diameter (in.) Gasket Volume (cubic in.) 0.573
Deck Clearance (in.)Note: Neg. nubmer above deck, Pos. number below deck Deck Volume (cubic in.) 0.246
Stroke (in.) STATIC COMPRESSION RATIO 7.774
COMPRESSION RATIO CALCULATOR
Static and Dynamic Compression Ratio
(Considers Cam Timing and Rod Ratio)
ENTER YOUR DATA CALCULATED DATA
Cylinder Head Volume (cc) Cylinder Head Vol (cubic in.) 1.220
Piston Head Volume (cc) Piston Head Vol (cubic in.) 3.050
Gasket Thickness (in.) Swept Volume (cubic in.) 34.473
Gasket Bore (in.) T.D.C. Volume (cubic in.) 5.089
Cylinder Bore Diameter (in.) Gasket Volume (cubic in.) 0.573
Deck Clearance (in.)Note: Neg. nubmer above deck, Pos. number below deck Deck Volume (cubic in.) 0.246
Stroke (in.) STATIC COMPRESSION RATIO 7.774
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- Joined: Wed Mar 25, 2009 12:50 pm
Re: Wasser bitching
Based on a .050" deck shim, and zero deck piston heights, and the vols you give, your low on compression at 8.1. for a 2258cc motor.. a .040" gasket is not much better at 8.3. most used gaskets, at least elring o/e, come in at about .045" after crush. as covered extensively in the forum by tencent and others, the way round it, apart from fitting a turbo,,,,,, is a longer con rod and a piston cut. a search will reveal all. most chamber volumes are 15cc for AMC and DJ heads. 18cc is common here and probably from MV. 20cc chamber ?? mmm, those plastic plunger cake icing type syringes all the speed shops sell are not the best, maybe inaccurate. a proper burette from a medical supply outlet is a far better tool for the job. if your .022" short of deck on the pistons, your figures seem about right.