i am getting ready to take my 1976 454 block in to have it cleaned, bored .060 and decked, want to use probe +39cc hollow dome pistons, should i have the machine shop just clean up the decks or have them machined to a specific height, they are factory height as of now, also how much quench should i be shooting for, i am using aluminum heads that with 118 chambers, thanks
scotty57406
measure your chambers. How many test fittings are you planning for? Are you assembling the engine your self? Is this a hot engine? Do you have your new roller cam yet to test for valve clearance?
Standard deck height for a 454 is 9.800". The measurement could vary from 9.790" to 9.820" for production tolerances. . The machine shop must check and machine the deck square to crank center line, on the correct angle and flat within .003" corner to corner. This must be done after an accurate crankshaft centerline align hone/bore is established and before any cylinder bore work.
The compression height of the Pistons will then determine the deck clearance after the deck height is set at 9.800".
The compression height of the Pistons will then determine the deck clearance after the deck height is set at 9.800".
Regarding quench, tell your machinist to shoot for .035/.045 for quench if you're running quality steel rods. A tight quench will minimize detonation and allow you to maximize timing. Good luck!
The compression height on most pistons for a 454 engine is 1.645. I would assembly all the pistons in the engine and take measurements on each cylinder. When I did mine I had .017 on #1 & 2 cylinders .019 on 7 & 8 cylinders and .016 on #4,#6, #3, & #5 cylinders. I then took it to my machinist who measured everything again. I had it lined bored and milled the decks enough to square everything. If I remember correctly I ended up with a deck height of .010. I then purchased a .030 compressed thickness head gasket set. I had a .040 quench.
i am buying new rods, thinking about scat i beam, i believe the pistons come in either pressed fit or floating pins so what would you guys suggest? i will be purchasing my parts through the machine shop since he can save on shipping due to his order quantities, i will ask him to shoot for the .035-.040 quench height, i appreciate you guys advice on this since the only shop i really ever dealt with has closed up and now i am dealing with a shop that a few people recommended, i don't want to be led down the garden path because he can make extra cash on machining i do not really need, thanks
I have always used pressed pins. Floating pins are too noisy for a street driven engine. Floating pins are for competition engines in case you need to change a piston in the pits.
A zero deck height is is best. The engine will run cooler. If you use low carbon forged or aluminum rods, you should consider having .015" to .020" deck clearance for rod stretch at high RPM. You can get by with zero deck clearance in a street driven engine if you stay well below the red line.
I set up a Pontiac 421 engine with zero deck clearance using rebuilt 1962 Pontiac forged rods with ARP bolts. After a year of racing, I tore the engine down and not one piston had zero deck clearance. That means the Pistons hit the heads and bent the rods due to rod stretch. You can run zero deck if you are using T6 aluminum rods, malleable cast iron production rods or heat treated forged rods that will not stretch at high RPM. SB Chevy engines don't seem to have problems with rod stretch due to the short stroke.
A zero deck height is is best. The engine will run cooler. If you use low carbon forged or aluminum rods, you should consider having .015" to .020" deck clearance for rod stretch at high RPM. You can get by with zero deck clearance in a street driven engine if you stay well below the red line.
I set up a Pontiac 421 engine with zero deck clearance using rebuilt 1962 Pontiac forged rods with ARP bolts. After a year of racing, I tore the engine down and not one piston had zero deck clearance. That means the Pistons hit the heads and bent the rods due to rod stretch. You can run zero deck if you are using T6 aluminum rods, malleable cast iron production rods or heat treated forged rods that will not stretch at high RPM. SB Chevy engines don't seem to have problems with rod stretch due to the short stroke.
not stirring anything but you are not using aluminum rods. Im sure it was a case of thinking of something else at that momment
This is an old argument. Floated rods vs pressed rods. There are pros and cons on both sides of the subject.
Full floating forged Pistons make more noise, not the pins. That usually occurs when bushed rods and forged Pistons are used in daily driver engines. Modern engines use cast Pistons with .0015" skirt clearances. Forged low silicon Pistons have from .006" to .012" cylinder wall clearances and use floated pins and make more noise.
If you are using stock reconditioned rods, use Pistons designed for pressed pins. If you need new rods, buy aftermarket Forged I beam rods that have oil holes and are bushed for floating pins. Most modern aftermarket forged Pistons are designed for floated pins or pressed pins.
The pins in forged Pistons designed for floated rods are special type with squared ends for pin locks.
There is no horsepower to be gained from using floating pins.
Floating rods are only an advantage if you have a racing engine with frequent tear downs.
There are more potential failures with floated Pistons and rods.
If a floating pin lock fails, it will take the engine with it.
Full floating forged Pistons make more noise, not the pins. That usually occurs when bushed rods and forged Pistons are used in daily driver engines. Modern engines use cast Pistons with .0015" skirt clearances. Forged low silicon Pistons have from .006" to .012" cylinder wall clearances and use floated pins and make more noise.
If you are using stock reconditioned rods, use Pistons designed for pressed pins. If you need new rods, buy aftermarket Forged I beam rods that have oil holes and are bushed for floating pins. Most modern aftermarket forged Pistons are designed for floated pins or pressed pins.
The pins in forged Pistons designed for floated rods are special type with squared ends for pin locks.
There is no horsepower to be gained from using floating pins.
Floating rods are only an advantage if you have a racing engine with frequent tear downs.
There are more potential failures with floated Pistons and rods.
If a floating pin lock fails, it will take the engine with it.
Aluminum heads will not tolerate a thin gasket, they need a thicker composition gasket. So, measure your stack of parts....... piston compression height, rod length and crank stroke radius (2.000" for stock 454) and add together to find your stack height. For instance, 1.645" piston compression height, plus 6.135" rod length, plus 2.000" crank stroke radius equals 9.780". Cut the block decks to 9.780" and use a 0.035" to 0.045" thick composition gasket to set the squish/quench. Use Fel-Pro 1017-1 for Mark IV, Use Fel-Pro 1047 for Gen V and Gen VI. Summit sells the 1017-1 as a 10171....
https://www.summitracing.com/parts/...e66BRDhnrizmcGc8VcSJABR6gaRdQb-TBgu4RFOTNs88ghlxW1QOrJofbgs4fHp9S9-XxoCIUfw_wcB
The other thing that you want to address with aluminum heads is that you use a gasket that has pre-flattened fire rings to prevent brinelling the aluminum. The 10171 meets this need.
https://www.summitracing.com/parts/...e66BRDhnrizmcGc8VcSJABR6gaRdQb-TBgu4RFOTNs88ghlxW1QOrJofbgs4fHp9S9-XxoCIUfw_wcB
The other thing that you want to address with aluminum heads is that you use a gasket that has pre-flattened fire rings to prevent brinelling the aluminum. The 10171 meets this need.
welcome back tech , bin awhile, 64nailhead you can bet on it that i am paying attention, i never realized that there was so many small details involved in having the block decked properly and achieving a good quench height, with all the input yous have given me i have a much clearer picture on how to proceed with my build, thanks all, scotty
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