454 to 540 ?
04-17-2014, 05:09 PM
#11
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you would need a bowtie tall deck to get anywhere a 540cid engine in a 454 block..not enough safe meat in the cylinder walls on a gm 454 tall deck.....with a set of daty ovals and a special grind i have you can get 600 ponys out of your 454 in a 489 configuration..
04-17-2014, 05:19 PM
#12
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I guess I didn't directly answer this. Personally, I would go with a Dart Pro series block and do a 540. I run these blocks as well as aluminum in my drag car at 567" and 580" respectively. I wouldn't bore the thing to 4.6" like a race car though. I like a little meat between the cylinders on marine engines.
In any case, we sonic test every block, in 12 places on each cylinder, before determining a safe over bore size. Don't accept any "generalizations" on wall thickness and which blocks are better than others. Insist on sonic test data, including the calibrated sound velocity value for your particular block.
04-17-2014, 05:33 PM
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A little block filler goes a long way too. Remember, the fill amount and cylinder flex reduction are not a linear equation. If you fill a block 25%, it may reduce flex by 35%...it's exponential to a certain point.
I had a customer with stock 502 blocks at 528" making 800+ each with pro chargers. The blocks were half filled. It is still in service after 10+ years. (With routine freshening, of course)
04-17-2014, 05:51 PM
#15
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The top class in offshore racing for many years had a cubic inch limit of .....Two engines no more than 1,000 cubic inches. Almost everyone one of our boats had two 496 motors......just like the one in my avatar here.
04-17-2014, 07:23 PM
#16
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What is this motor going in?? A 468 with some good heads is a great Low Budget motor for single engine applications with a Bravo drive. we raced a 26' Corsa with a 468 and a Bravo drive and ran mid 80's mph. I wouldn't spin it much past 5500 rpm for too long unless you spend the cash for a good rotating assy. If you cant get the Cubes you want then Heads are the Key. There is a difference of about 200 hp from the crappy heads to the semi expensive good ones... Lots of good info in this thread....
04-17-2014, 07:49 PM
#17
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Matching the head to the cubic inch and rpm is paramount. We have build combinations that made over 700hp with a GM 781/049 oval port head. You have to be careful not to fall into the "bigger is better" trap, just because the price is the same.
A properly prepped 270cc intake runner head will outperform a 310cc Brodix on a 468 on HP and TQ. In addition, the BSFC will be lower, netting better economy. It's all about air speed, atomization and cylinder filling.
Camshaft is also very important. There are a few key considerations.
1. Intake events and valve lift, in relation to piston speed ATDC. At 70°-75° Of crankshaft rotation, this is when the piston is moving the fastest. You need to match this to events at the valve when the port is able to flow very strong. Remember, engines do not make vacuum, per-say, on the intake stroke, they just try to equalize the pressure differential between the cylinder and the atmosphere outside the engine.
2. Intake valve closing events. This is dependent on airspeed and will dictate cylinder filling ABDC. Close the valve too soon and you lose intake charge. Close it too late and you will back charge up the intake tract. Late closing is also responsible for low cylinder pressure.
3, Exhaust opening events. If you open the exhaust too soon BBDC, you will blow off some of the pressure meant to push the crank down on the power stroke. This in turn leads to pumping losses on the exhaust stroke.
4. Obviously, lift comes into play with the cylinder head data as well. Lobe centerlines and duration almost fall into place when calculating the timing events that are required for each engine.
Engine design is very fun to do. I've been fortunate enough to do this as a living for close to 30 years now, and over 25 with my own business. Each engine is a challenge as well as a job. I would not do it if I didn't enjoy it.
I suggest anyone getting an engine built to learn as much as they can and be involved as much as possible with the build. It's very rewarding.
A properly prepped 270cc intake runner head will outperform a 310cc Brodix on a 468 on HP and TQ. In addition, the BSFC will be lower, netting better economy. It's all about air speed, atomization and cylinder filling.
Camshaft is also very important. There are a few key considerations.
1. Intake events and valve lift, in relation to piston speed ATDC. At 70°-75° Of crankshaft rotation, this is when the piston is moving the fastest. You need to match this to events at the valve when the port is able to flow very strong. Remember, engines do not make vacuum, per-say, on the intake stroke, they just try to equalize the pressure differential between the cylinder and the atmosphere outside the engine.
2. Intake valve closing events. This is dependent on airspeed and will dictate cylinder filling ABDC. Close the valve too soon and you lose intake charge. Close it too late and you will back charge up the intake tract. Late closing is also responsible for low cylinder pressure.
3, Exhaust opening events. If you open the exhaust too soon BBDC, you will blow off some of the pressure meant to push the crank down on the power stroke. This in turn leads to pumping losses on the exhaust stroke.
4. Obviously, lift comes into play with the cylinder head data as well. Lobe centerlines and duration almost fall into place when calculating the timing events that are required for each engine.
Engine design is very fun to do. I've been fortunate enough to do this as a living for close to 30 years now, and over 25 with my own business. Each engine is a challenge as well as a job. I would not do it if I didn't enjoy it.
I suggest anyone getting an engine built to learn as much as they can and be involved as much as possible with the build. It's very rewarding.
04-17-2014, 09:08 PM
#19
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Matching the head to the cubic inch and rpm is paramount. We have build combinations that made over 700hp with a GM 781/049 oval port head. You have to be careful not to fall into the "bigger is better" trap, just because the price is the same.
A properly prepped 270cc intake runner head will outperform a 310cc Brodix on a 468 on HP and TQ. In addition, the BSFC will be lower, netting better economy. It's all about air speed, atomization and cylinder filling.
Camshaft is also very important. There are a few key considerations.
1. Intake events and valve lift, in relation to piston speed ATDC. At 70°-75° Of crankshaft rotation, this is when the piston is moving the fastest. You need to match this to events at the valve when the port is able to flow very strong. Remember, engines do not make vacuum, per-say, on the intake stroke, they just try to equalize the pressure differential between the cylinder and the atmosphere outside the engine.
2. Intake valve closing events. This is dependent on airspeed and will dictate cylinder filling ABDC. Close the valve too soon and you lose intake charge. Close it too late and you will back charge up the intake tract. Late closing is also responsible for low cylinder pressure.
3, Exhaust opening events. If you open the exhaust too soon BBDC, you will blow off some of the pressure meant to push the crank down on the power stroke. This in turn leads to pumping losses on the exhaust stroke.
4. Obviously, lift comes into play with the cylinder head data as well. Lobe centerlines and duration almost fall into place when calculating the timing events that are required for each engine.
Engine design is very fun to do. I've been fortunate enough to do this as a living for close to 30 years now, and over 25 with my own business. Each engine is a challenge as well as a job. I would not do it if I didn't enjoy it.
I suggest anyone getting an engine built to learn as much as they can and be involved as much as possible with the build. It's very rewarding.
A properly prepped 270cc intake runner head will outperform a 310cc Brodix on a 468 on HP and TQ. In addition, the BSFC will be lower, netting better economy. It's all about air speed, atomization and cylinder filling.
Camshaft is also very important. There are a few key considerations.
1. Intake events and valve lift, in relation to piston speed ATDC. At 70°-75° Of crankshaft rotation, this is when the piston is moving the fastest. You need to match this to events at the valve when the port is able to flow very strong. Remember, engines do not make vacuum, per-say, on the intake stroke, they just try to equalize the pressure differential between the cylinder and the atmosphere outside the engine.
2. Intake valve closing events. This is dependent on airspeed and will dictate cylinder filling ABDC. Close the valve too soon and you lose intake charge. Close it too late and you will back charge up the intake tract. Late closing is also responsible for low cylinder pressure.
3, Exhaust opening events. If you open the exhaust too soon BBDC, you will blow off some of the pressure meant to push the crank down on the power stroke. This in turn leads to pumping losses on the exhaust stroke.
4. Obviously, lift comes into play with the cylinder head data as well. Lobe centerlines and duration almost fall into place when calculating the timing events that are required for each engine.
Engine design is very fun to do. I've been fortunate enough to do this as a living for close to 30 years now, and over 25 with my own business. Each engine is a challenge as well as a job. I would not do it if I didn't enjoy it.
I suggest anyone getting an engine built to learn as much as they can and be involved as much as possible with the build. It's very rewarding.
With only 6 posts......where the heck have you been hiding for 3 years? Nice posts!
04-17-2014, 09:28 PM
#20
Gold Member
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LOL - Took the words I was thinking while reading that.
"Who in the F is this dude and where the F did HE come from?!" Rev Ronnie will get along great around here. Way to kick it off on OSO bro! Nice!
