I'm building another solid roller 427 SBC
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Safety Car
Joined: Nov 2005
Posts: 3,961
Likes: 573
From: Lompoc, CA. Santa Barbara County
How you doing Gordon? I see you survived and prolly thrived.
Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
As for me and sending the first wife down the river.......... I actually had a lady judge and I was worried. But like the ruling on my home she was very fair. I had put a down and owned a home before I met the wife. So the judge ruled that she was only entitled to 1/2 of the appreciation equity aquired during the 5 years of marriage. She was also responsible for her credit cards and car payments and I got 1/2 the value of all the items aquired while we were married.
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
A point to ponder...
Why would the split in duration be uniform, the same split at any given tappet height, throughout the lift range of the tappet when you are dealing with one port that is based on creating a depression so it can function and one port that is dealing with very high pressure at the beginning of tappet rise and quickly bleeds down from there.
Why would the split in duration be uniform, the same split at any given tappet height, throughout the lift range of the tappet when you are dealing with one port that is based on creating a depression so it can function and one port that is dealing with very high pressure at the beginning of tappet rise and quickly bleeds down from there.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
You need a custom shaft rocker setup. I tried Jesel but the wait was too long. T&d set me up pretty fast but the first didn't work they were way off. They actually make you a custom set just for your motor no off the shelf stuff.
I finally got the correct set, you use shims to get them perfect on the valve, I have have not had a problem with them, and I take a look twice a year and I haven't had to make any lash adjustments in three years now.
Once you go to shaft rockers you will never go back, sure they are expensive but once you get a set a set you will see what I am talking about and you need a custom set up anyway with those headers and the shaft rockers make both intake an exhaust pushrods perfectly vertical.
I have revved mine up to 8,000 RPM and it took it even though I am not making any more than 7,000RPM. buy nothing from Eagle and constrain yourself from making max HP as you want to be able criuse around town. I could have made more HP but I wanted a engine that was "streetable"
I finally got the correct set, you use shims to get them perfect on the valve, I have have not had a problem with them, and I take a look twice a year and I haven't had to make any lash adjustments in three years now.
Once you go to shaft rockers you will never go back, sure they are expensive but once you get a set a set you will see what I am talking about and you need a custom set up anyway with those headers and the shaft rockers make both intake an exhaust pushrods perfectly vertical.
I have revved mine up to 8,000 RPM and it took it even though I am not making any more than 7,000RPM. buy nothing from Eagle and constrain yourself from making max HP as you want to be able criuse around town. I could have made more HP but I wanted a engine that was "streetable"
Last edited by MotorHead; Feb 22, 2014 at 11:16 AM.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Ill second that motorhead. Keep "listening" for maybe one that would go out of wack and with shaft rockers they just dont.
No stud deflection either with larger cams gets a little scary way things move around so much. Cant be good for anything.
Sucks paying for them but only have to buy them once
No stud deflection either with larger cams gets a little scary way things move around so much. Cant be good for anything.
Sucks paying for them but only have to buy them once
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Drifting
Joined: Oct 2005
Posts: 1,528
Likes: 148
From: East London/SW Essex UK
I wonder guys if we were to all move forward perhaps another 10 years plus (and presuming the internal combustion engine as we know it still around and not legislated out of existance) - whether we will all be talking about electronic/hydraulic valve operation. In the same way that current ignition and fuel delivery systems are all ECU based and that the 'mechanical' side of this part of engine control has been engineered out - why not valve operation - i.e throw away the camshaft and instead electronically actuate high pressure hydraulically operated inlet and exhaust valves. Valve springs could also be eliminated by using desmodronic operation. No worries then about overdoing it with valve lift and timing events as it will all be ECU driven. You wouldn't need to even be concerned about valve to piston clearance as sensors could monitor this. You could have totally different 'tunes' for economy cruise and performance in the same way as currently offered aftermarket add-on fuel injection systems.
I'm dreaming a bit fella's
I'm dreaming a bit fella's
Racer
Joined: Jul 2013
Posts: 294
Likes: 10
From: Palmer Alaska
I wonder guys if we were to all move forward perhaps another 10 years plus (and presuming the internal combustion engine as we know it still around and not legislated out of existance) - whether we will all be talking about electronic/hydraulic valve operation. In the same way that current ignition and fuel delivery systems are all ECU based and that the 'mechanical' side of this part of engine control has been engineered out - why not valve operation - i.e throw away the camshaft and instead electronically actuate high pressure hydraulically operated inlet and exhaust valves. Valve springs could also be eliminated by using desmodronic operation. No worries then about overdoing it with valve lift and timing events as it will all be ECU driven. You wouldn't need to even be concerned about valve to piston clearance as sensors could monitor this. You could have totally different 'tunes' for economy cruise and performance in the same way as currently offered aftermarket add-on fuel injection systems.
I'm dreaming a bit fella's
I'm dreaming a bit fella's
Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
A point to ponder...
Why would the split in duration be uniform, the same split at any given tappet height, throughout the lift range of the tappet when you are dealing with one port that is based on creating a depression so it can function and one port that is dealing with very high pressure at the beginning of tappet rise and quickly bleeds down from there.
Why would the split in duration be uniform, the same split at any given tappet height, throughout the lift range of the tappet when you are dealing with one port that is based on creating a depression so it can function and one port that is dealing with very high pressure at the beginning of tappet rise and quickly bleeds down from there.
They are slightly different. But I have been working on engine similator software for 15 years or so. From the desktop dyno 2000 to the modern expensive programs used today.
The software is just a tool and older less sophisticated software over rewarded big number split duration cams. Like an additional 10-16 degrees on the exhaust side. That did not pan out in real life motors with high flowing exhaust ports.
So when you have high flow exhaust on the heads, free flowing pipes, and high exhaust lifts like .714 gross numbers. The need for an additional 8-12 degrees on the exhaust side is a moot point.
I've noticed on your cams bigger exhaust duration and less lift than the intake. The total flow on an exhaust valve event can be accomplished just as much with shorter duration and higher lift.
I'm not saying that you are wrong. It is just two trains of thought to accomplish the same thing.
To you others.......... T&D is a fellow shop in the area and one of their workers builds his sheet metal intake manifolds at our shop during his off hours
Last edited by gkull; Feb 22, 2014 at 03:34 PM.
Race Director
Joined: Nov 2006
Posts: 19,445
Likes: 353
From: Athens GA
St. Jude Donor '12-'13, '15- '16-'17-'18-'19, '21
Same here.................wish I had it back now.
George -
So sad to hear it was stolen. It's almost as bad as losing a loved one (emphasis on almost)
Glad you got the shell back .......the Phoenix will rise again.
Bman
George -
So sad to hear it was stolen. It's almost as bad as losing a loved one (emphasis on almost)
Glad you got the shell back .......the Phoenix will rise again.
Bman
Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I could have used the same lobe profiles and had the custom cam ground on 104 -108 lobe centers and the valve event numbers advanced to make big numbers and a peaky motor with 30-60 more HP.
But you end up with poor MPG, 1200 rpm idle, choppy race car sound, no vacuum, and need a 5-6 speed closed ratio tranny.
But if you want a higher average broad power curve VS bragging rights just make a happy motor that just does it all. When you get into the mid 600 HP motors it takes a good driver to actually be able to use the power. You have to have the best tires to even stay straight in the first couple of gears. They are even dangerous cars to drive.
Look at the death of our fast and furious drive in a 600 hp Porsche. that is why I have 335 rears and a full roll cage
But you end up with poor MPG, 1200 rpm idle, choppy race car sound, no vacuum, and need a 5-6 speed closed ratio tranny.
But if you want a higher average broad power curve VS bragging rights just make a happy motor that just does it all. When you get into the mid 600 HP motors it takes a good driver to actually be able to use the power. You have to have the best tires to even stay straight in the first couple of gears. They are even dangerous cars to drive.
Look at the death of our fast and furious drive in a 600 hp Porsche. that is why I have 335 rears and a full roll cage
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
George why not go with Isky EZ roll lifters? I indoctrinated my buddy into the EZ roll camp now he has been using them in all his USAC 410 sprint car motors. One motor has over 200+ races on a set with no appreciable wear! His shop used to pitch roller lifters after 50 races...Isky Red Zone/Crower HIPPO neither would go much further than the 50 race threshold. Isky/Crower will even rebuild their Red Zone/HIPPO lifters with bushings now. If I were having Larry Torres make me a set of shaft rockers, I would go with steel rocker arms like the Cup boys run
Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I don't worry about driving at sea level either As to the Isky EZ roll lifters.
Like Chris posted: I should take the block back and have the lifter bores enlarged to get the bigger diameter rollers.
I'm not running massive spring pressure on these relatively low rpm motors. 205 closed and 580 or so open
As to the Isky EZ roll lifters.Like Chris posted: I should take the block back and have the lifter bores enlarged to get the bigger diameter rollers.
I'm not running massive spring pressure on these relatively low rpm motors. 205 closed and 580 or so open
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
They are slightly different. But I have been working on engine similator software for 15 years or so. From the desktop dyno 2000 to the modern expensive programs used today.
The software is just a tool and older less sophisticated software over rewarded big number split duration cams. Like an additional 10-16 degrees on the exhaust side. That did not pan out in real life motors with high flowing exhaust ports.
So when you have high flow exhaust on the heads, free flowing pipes, and high exhaust lifts like .714 gross numbers. The need for an additional 8-12 degrees on the exhaust side is a moot point.
I've noticed on your cams bigger exhaust duration and less lift than the intake. The total flow on an exhaust valve event can be accomplished just as much with shorter duration and higher lift.
I'm not saying that you are wrong. It is just two trains of thought to accomplish the same thing.
To you others.......... T&D is a fellow shop in the area and one of their workers builds his sheet metal intake manifolds at our shop during his off hours
The software is just a tool and older less sophisticated software over rewarded big number split duration cams. Like an additional 10-16 degrees on the exhaust side. That did not pan out in real life motors with high flowing exhaust ports.
So when you have high flow exhaust on the heads, free flowing pipes, and high exhaust lifts like .714 gross numbers. The need for an additional 8-12 degrees on the exhaust side is a moot point.
I've noticed on your cams bigger exhaust duration and less lift than the intake. The total flow on an exhaust valve event can be accomplished just as much with shorter duration and higher lift.
I'm not saying that you are wrong. It is just two trains of thought to accomplish the same thing.
To you others.......... T&D is a fellow shop in the area and one of their workers builds his sheet metal intake manifolds at our shop during his off hours
Good flowing exhaust doen't need huge splits. Your correct. Based on the I/E ratio of a head you can quickly see if an engine has the wrong cam in it.
Lift means nothing on an exhaust port. Most of the exhaust has escaped at low lift because the exhaust port is under such extreme pressure. As soon as the valve is opened it wants out!! How much time the valve is held open (Duration) is what is important.
I will disagree with you on high lift and short duration. It won't work on a poor flowing exhaust port.
My cams are based on the customers wants and his combination. Some heads require more split than others. Alot of the stock heads from GM on the LS stuff require large splits. Some of of the aftermarket stuff require very narrow splits.
My point is the split between intake and exhaust should never be equal through the lift points because the ports are opposites.
Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Slightly different....they aren't even close in how they function. One is creating a depression and one is under extreme pressure. The are polar opposites.
Good flowing exhaust doen't need huge splits. Your correct. Based on the I/E ratio of a head you can quickly see if an engine has the wrong cam in it.
Lift means nothing on an exhaust port. Most of the exhaust has escaped at low lift because the exhaust port is under such extreme pressure. As soon as the valve is opened it wants out!! How much time the valve is held open (Duration) is what is important.
I will disagree with you on high lift and short duration. It won't work on a poor flowing exhaust port.
My cams are based on the customers wants and his combination. Some heads require more split than others. Alot of the stock heads from GM on the LS stuff require large splits. Some of of the aftermarket stuff require very narrow splits.
My point is the split between intake and exhaust should never be equal through the lift points because the ports are opposites.
Good flowing exhaust doen't need huge splits. Your correct. Based on the I/E ratio of a head you can quickly see if an engine has the wrong cam in it.
Lift means nothing on an exhaust port. Most of the exhaust has escaped at low lift because the exhaust port is under such extreme pressure. As soon as the valve is opened it wants out!! How much time the valve is held open (Duration) is what is important.
I will disagree with you on high lift and short duration. It won't work on a poor flowing exhaust port.
My cams are based on the customers wants and his combination. Some heads require more split than others. Alot of the stock heads from GM on the LS stuff require large splits. Some of of the aftermarket stuff require very narrow splits.
My point is the split between intake and exhaust should never be equal through the lift points because the ports are opposites.
Since when is 256 cfm poor exhaust flow
As to I/E ratio. That is another stupid comment. If both of them are massive who cares? David Vizzard, used those generalizations all the time. AFR 245cc heads are not some general SBC low performance head.Real SBC race heads use 2.25 intake valves and tiny 1.5 inch exhausts.
Because the bore diameter doesn't allow anything bigger. So they have found that big intake cfm is more rewarding than the exhaust side. Yes, and they are lifting the valves to @ 1.00 inches.
These two lobes are not the same either.
CC lobe #4009 290-5 254 171 .420 .119 .105 .630 .672 .714
CC lobe #4008 292-5 256 173 .420 .123 .108 .630 .672 .714
