stroked small blocks in the race cars?

[xb-60]

Double post

[blykins]

Originally Posted by CompClassics

Blykins,

What is your thought on running a hydraulic cam profile using mechanical roller lifters? Longevity?

Same deal.

Any solid lifter will need lash and more spring pressure to keep the valvetrain happy. When you introduce lash into the system, then the lifter is not in contact with the cam lobe all the time. Add spring pressure to that and you get a hammering effect on the lifter's roller bearings. Over time, it hammers them down. Even the most expensive lifters made for "street use" will not last a long time.

With the amount of research that I've done on hydraulic roller cams in the past several years, there's no need to run a solid roller unless it's a race application where aggressive cam lobes are necessary. I've had my FE engines at 7500 rpm with a hydraulic roller camshaft.

[1795]

Thanks for al of the input guys. My engine builder is going to be sorry he ever agreed to do the build I will have a lot to discuss with him. He reminds me of Brent, he lives in farm country, his shop started out as his garage and has slowly expanded over time. There is a local drag strip, so he does a lot of drag racers, also does some street stuff, an occasional road race car, and in addition to a variety of small block and big block Ford engines in his shop, there is a tractor engine on the bench.

I sent an email to Dan Case and asked if he knew the specs on what the 289 race cars were using for a cam and he said that in his 289 with Webers he is running the C7FE cam, which is what Ford sold off the shelf for race applications. He thought that it had a lobe separation of 107. I looked up on the web and this is what I found:
http://nebula.wsimg.com/8590605db382...&alloworigin=1

Another site said that the duration of that cam was 250, with an intake lift of .528@.050" and a lobe separation of 108.

Does this sound similar to what you guys are thinking?

Jim

[Mark IV]

Originally Posted by 1795

Thanks for al of the input guys.

Will Rick be pi$$ed that I sent you there?

[blykins]

Originally Posted by 1795

Thanks for al of the input guys. My engine builder is going to be sorry he ever agreed to do the build I will have a lot to discuss with him. He reminds me of Brent, he lives in farm country, his shop started out as his garage and has slowly expanded over time. There is a local drag strip, so he does a lot of drag racers, also does some street stuff, an occasional road race car, and in addition to a variety of small block and big block Ford engines in his shop, there is a tractor engine on the bench.

I sent an email to Dan Case and asked if he knew the specs on what the 289 race cars were using for a cam and he said that in his 289 with Webers he is running the C7FE cam, which is what Ford sold off the shelf for race applications. He thought that it had a lobe separation of 107. I looked up on the web and this is what I found:
http://nebula.wsimg.com/8590605db382...&alloworigin=1

Another site said that the duration of that cam was 250, with an intake lift of .528@.050" and a lobe separation of 108.

Does this sound similar to what you guys are thinking?

Jim

The factory cam would have been picked for factory heads and factory part combinations. Today's parts, including Dart heads, would change the specs. It could be that you would need a 106, or maybe even a 109-110, but I would have to get the head stats in front of me along with all the other parts.

I wasn't suggesting that you go back to 60's cam specs, I was only suggesting that you get away from the normal "internet spec'd" camshafts, with long LSA's.

[1795]

He probably is having nightmares already. He actually is enjoying the build and every time I talk to him he starts off by saying he did some more research last night.

I will be doing a balancing act between what I would like to see, what you guys suggest, and trying not to step on his toes too much, as he is the engine builder and knows more about it than I do. He has a good reputation, so I do need to heed his advice, as he is the one that will be building the engine.

Jim

[olddog]

Originally Posted by blykins

Same deal.

Any solid lifter will need lash and more spring pressure to keep the valvetrain happy. When you introduce lash into the system, then the lifter is not in contact with the cam lobe all the time. Add spring pressure to that and you get a hammering effect on the lifter's roller bearings. Over time, it hammers them down. Even the most expensive lifters made for "street use" will not last a long time.

With the amount of research that I've done on hydraulic roller cams in the past several years, there's no need to run a hydraulic solid roller unless it's a race application where aggressive cam lobes are necessary. I've had my FE engines at 7500 rpm with a hydraulic roller camshaft.

I believe I fixed a typo. Delete to word hydraulic (in red) and insert the word solid in bold. I couldn't find a way to strike through a word.
Excuse me if I am wrong.

I might add a hydraulic lifter acts as a dampener to reduce the shockwave of metal hitting metal. I think the oil pressure in the hydraulic lifter holds the lifter in contact with the cam, but I'm not certain of that.

[MAStuart]

Jim you started off by just wanting to freshen your engine. Now after listening to all of us you are heading toward one of them $25 to 35 thousand dollar new engine. Its easy for us to spend your money. In the end it is between you your engine builder.

C7FE cam would be a big step backwards if your running a roller now. They sound good. I have one I took out of a 67 Shelby. My kids want me to put in in my Gurney Eagle engine because they think it would sound so cool. They also think it would pick up a bunch of power because it has such a mild hyd cam in it now.


Do you feel you need a bunch more power or just more RPM to carry you thru if you need it.

I am just a hobby guy that likes small block ford engines. I dont have to pay for any engine work. I do all my own work.

[blykins]

Originally Posted by olddog

I believe I fixed a typo. Delete to word hydraulic (in red) and insert the word solid in bold. I couldn't find a way to strike through a word.
Excuse me if I am wrong.

I might add a hydraulic lifter acts as a dampener to reduce the shockwave of metal hitting metal. I think the oil pressure in the hydraulic lifter holds the lifter in contact with the cam, but I'm not certain of that.

You are correct. Should have been solid instead of hydraulic.

[blykins]

Originally Posted by MAStuart

Jim you started off by just wanting to freshen your engine. Now after listening to all of us you are heading toward one of them $25 to 35 thousand dollar new engine. Its easy for us to spend your money. In the end it is between you your engine builder.

C7FE cam would be a big step backwards if your running a roller now. They sound good. I have one I took out of a 67 Shelby. My kids want me to put in in my Gurney Eagle engine because they think it would sound so cool. They also think it would pick up a bunch of power because it has such a mild hyd cam in it now.


Do you feel you need a bunch more power or just more RPM to carry you thru if you need it.

I am just a hobby guy that likes small block ford engines. I dont have to pay for any engine work. I do all my own work.

I agree and if I was unclear, I'm not saying that Jim should run a factory flat tappet. I'm suggesting a new solid roller with specs that correlate to the application.

[1795]

Originally Posted by blykins

I agree and if I was unclear, I'm not saying that Jim should run a factory flat tappet. I'm suggesting a new solid roller with specs that correlate to the application.

I know, I was just asking if the lobe separation, lift, duration, etc., were in line with what you were thinking. I have no plans to go backwards in time and put in and old school cam.. Just helping me understand your thought process.

[1795]

Originally Posted by MAStuart

Jim you started off by just wanting to freshen your engine. Now after listening to all of us you are heading toward one of them $25 to 35 thousand dollar new engine. Its easy for us to spend your money. In the end it is between you your engine builder.

C7FE cam would be a big step backwards if your running a roller now. They sound good. I have one I took out of a 67 Shelby. My kids want me to put in in my Gurney Eagle engine because they think it would sound so cool. They also think it would pick up a bunch of power because it has such a mild hyd cam in it now.


Do you feel you need a bunch more power or just more RPM to carry you thru if you need it.

I am just a hobby guy that likes small block ford engines. I dont have to pay for any engine work. I do all my own work.

Yes it is easy to spend someone else's money As the engine was torn down it was apparent that some things needed to be addressed. It will be a couple of thousand more than I had planned, but still well south of $25K.

[blykins]

Duration would be in the ballpark. Hard to comment on lift and LSA without knowing if any head work has been completed. Porting changes a lot of things including the duration split and even the LSA itself.

For most small displacement road race engines, a tighter LSA will make a huge difference in torque and how much throttle response is available down low.

[Anthony]

Originally Posted by olddog

I might add a hydraulic lifter acts as a dampener to reduce the shockwave of metal hitting metal. I think the oil pressure in the hydraulic lifter holds the lifter in contact with the cam, but I'm not certain of that.

Yes, that is because the lifter is in constant contact with the lobe of the cam, and lash is always at zero. I think the contour of the cam, after the lobe, is different between solid and hydraulic cams. Hydraulic lifters have spring loaded plungers with the added effect of the oil pressure to keep the lifter in constant contact with the camshaft.

[CompClassics]

“I think the contour of the cam, after the lobe, is different between solid and hydraulic cams.”

This was what my question was mostly regarding, would the less aggressive profile of the camshaft allow for longevity of the valve train?

[eschaider]

Originally Posted by xb-60

Ed, how did you simulate the areas on the pistons that are stressed differently in your situation by the forced induction ? That must have been a challenge?
Cheers
Glen

The finite element simulation software provides tools to load different portions of the piston as you see fit. In the simplest model you start with a crank slider mechanism dimensioned to mimick your crank, rods, and pistons and then start to increase crank rpm and watch as the stresses build in the model. Red will be high stress, blue typically is low stress. As you add or remove mass from various points in the model you can see the impact it has by the change in color.


Ed

[Anthony]

Originally Posted by CompClassics

“I think the contour of the cam, after the lobe, is different between solid and hydraulic cams.”

This was what my question was mostly regarding, would the less aggressive profile of the camshaft allow for longevity of the valve train?

It’s my understanding, that with solid lifter cams, after the value closes, the lobe decreases another .015”, whatever the lash is, and the lobe remains constant until the next time the valve opens, when the lobe ramps up again. This is in contrast to a hydraulic cam, where after the valve closes , the lobe ever slow gradually decreases in lift until the valve begins to open again. Which surprised me when I read in the engine masters challenge, i think the one engine was using solid lifters with a hydraulic cam.

[eschaider]

Originally Posted by CompClassics

Blykins,

What is your thought on running a hydraulic cam profile using mechanical roller lifters? Longevity?

Camshafts are ground with a lobe rising off a camshaft base circle. The amount or rise the lobe exhibits above the base circle multiplied by the rocker ratio is the lift observed at the valve less any mechanical distortions in the mechanism while operating.

As the cam grinder transitions from base circe to the opening ramp on the cam he builds in something called a clearance ramp. For solid lifter cams this is a gradual take up of the valve lash designed to minimize the hammering effect each time the lifter experiences moving from the cam base circle to the actual opening ramp of the cam.

Cam designers sometimes will speak of 0.006" lift durations and also 0.050" lift dutrations. The 0.006" lift duration is essentially the beginning of the actual opening ramp after the clearance ramp and represents the beginning of actual valve movement. This number is helpful in backing into some things like ramp acceleration rates. The intake port will not begin to flow significant air volume until the 0.050" lift point. This is the Harvey Crane originated duration measurement point for guys like us to compare cams.

This is a pic of a cam lobe from CompCams identifying the nomenclature associated with the various points on the cam lobe. Notice the clearance ramp notation on the lower right of the picture.



When you cut a cam for solid lifters (roller or flat) you need to provide clearance ramps to take up the valve lash gently without hammering the operating components to death. The Hydraulic lifter cam (roller or flat face) has no valve lash to take up because of the hydraulic lifter's 100% in contact with the lobe design.

As a result the clearance ramp used on a solid lifter cam to soften the impact on valvetrain components at each valve opening event is not present on a hydraulic lifter version cam. If you put a solid lifter tappet (roller or flat face) onto a hydraulic grind camshaft it would have a much foreshortened service life because of the hammering effect the valvetrain would experience without the clearance ramps.

Because a hydraulic lifter (roller or flat face) always operates at zero lash, hydraulic lifters can be safely placed on solid lifter grind cams but that begs the question why would you do this, other than to get away from lashing the valves — there is no performance advantage.

If the cam was ground as a solid lifter cam use solid lifters (lashed correctly), If it was ground as a hydraulic lifter cam use hydraulic;ic lifters. Don't mess with the primal forces of nature.


Ed

[PDUB]

Originally Posted by blykins

For most small displacement road race engines, a tighter LSA will make a huge difference in torque and how much throttle response is available down low.

Does the smaller angle increase or decrease torque and throttle response, or do those go in opposite directions?

[blykins]

There are "universal" lobes. Some lobes will tolerate hydraulic lifters or solid lifters. With the lobes that are as such, the lash spec will be very low with solid lifters, such as .005-.010".

In getting back to running solid lifters on hydraulic cams, I've seen guys try that because the hydraulic cam wouldn't rev. Generally, that's not a lifter issue, it's because the cam wasn't spec'd correctly, valvetrain isn't light enough, or things are just not right in general. Putting a solid lifter on a hydraulic lobe in that situation is a band-aid only.

Keep in mind that there are also "aggressive" hydraulic lobes and aggressive solid lobes. The key is choosing the correct one for the application. You don't want hydraulic lobes so aggressive that the lifters can't keep up and you don't want solid lobes so aggressive that they eat valve springs.