Testing another new product
#41
I wish I knew why Olds did a lot of different things. I've never understood why they used 39* & 45* blocks. They used both during the same model year run some years. As far as the .921 lifter goes maybe they were planning on using some better cams but never did. According to some it's irrelevant but it sure helps a guy who wants to run a very aggresive cam.
as far as going away from the 45 bank I think it was to accommodate future big bores like the 403.
The lifter banks needed to be moved inboard to clear the bores. It’s still very close in the 403 now , it wouldn’t work if they didn’t move them inboard
Last edited by CANADIANOLDS; December 4th, 2022 at 10:43 AM.
#43
There are pros and cons to larger lifters. Obviously a smaller diameter lifter could be lighter, but you can also use a larger wheel with a larger diameter lifter which slows down the wheel speed as well and give a degree or two more effective duration.
I have two DX builds upcoming. We just reamed them to use the .937 solid roller offered by Isky, BAM, and others. We’ll see how it does but I expect good results.
I have two DX builds upcoming. We just reamed them to use the .937 solid roller offered by Isky, BAM, and others. We’ll see how it does but I expect good results.
#44
At what point do larger lifters become advantageous? Then, at what point are they a disadvantage? I say it's a moot point because the window is so narrow and applies to even fewer applications.
How aggressive of a cam do you want?
How aggressive of a cam do you want?
Last edited by fleming442; December 4th, 2022 at 03:45 PM.
#45
I think the .921” was a leftover idea from the 394?
as far as going away from the 45 bank I think it was to accommodate future big bores like the 403.
The lifter banks needed to be moved inboard to clear the bores. It’s still very close in the 403 now , it wouldn’t work if they didn’t move them inboard
as far as going away from the 45 bank I think it was to accommodate future big bores like the 403.
The lifter banks needed to be moved inboard to clear the bores. It’s still very close in the 403 now , it wouldn’t work if they didn’t move them inboard
#46
At what point do larger lifters become advantageous? Then, at what point are they a disadvantage? I say it's a moot point because the window is so narrow and applies to even fewer applications.
How aggressive of a cam do you want?
https://youtu.be/7vBPUXxmloI
How aggressive of a cam do you want?
https://youtu.be/7vBPUXxmloI
#47
Mushroom lifters had nothing to do with diameter really. They were developed to make the best use of the diameter you had to work with. The mushroom shape essentially extended the contact patch so you got more effective duration.
#48
If they helped the cam,isn't that the purpose of them? I'm confused by your reasoning.
#49
#50
Lifter diameter had nothing to do with contact patch. Increased lifter diameter has more to do with lift, specifically, rate of lift. The higher the rate of lift causes the load on the lifter to move to the outside. A flat tappet can be so aggressive the contact point can move pass the outside diameter of the lifter causing the edge of the lifter to gall into the cam lobe. A mushroom lifter has a larger face than the body allowing for more aggressive ramps. In the case of the roller it has to do with side loading the lifter once again the larger the wheel the more aggressive it can be.
#51
Lifter diameter had nothing to do with contact patch. Increased lifter diameter has more to do with lift, specifically, rate of lift. The higher the rate of lift causes the load on the lifter to move to the outside. A flat tappet can be so aggressive the contact point can move pass the outside diameter of the lifter causing the edge of the lifter to gall into the cam lobe. A mushroom lifter has a larger face than the body allowing for more aggressive ramps. In the case of the roller it has to do with side loading the lifter once again the larger the wheel the more aggressive it can be.
#53
Lifter diameter had nothing to do with contact patch. Increased lifter diameter has more to do with lift, specifically, rate of lift. The higher the rate of lift causes the load on the lifter to move to the outside. A flat tappet can be so aggressive the contact point can move pass the outside diameter of the lifter causing the edge of the lifter to gall into the cam lobe. A mushroom lifter has a larger face than the body allowing for more aggressive ramps. In the case of the roller it has to do with side loading the lifter once again the larger the wheel the more aggressive it can be.
That has always been my thoughts on a larger diameter lifters. The larger the more aggressive you can be with the cam. I remember mushroom lifters from way back in the day.. What is the reasoning behind Mopar cam grinds used in GM cams? I've seen some Olds guys say they use Mopar profiles.
The "Hemi grind" profile can be put on any cam blank with enough material to grind. My step brother has a "Hemi grind" cam in his wedge head 383 Mopar. I believe I have either seen or heard someone putting an "LS" profile on an Olds cam.
Valve lifters are generally ground using a 40 inch radius on the bottom. One cam grinder will "resurface" lifters using a 36 inch radius on the bottom. This would allow faster opening ramps without scuffing the cam with the edge of the lifter.
Now come the comments.......
#54
That has always been my thoughts on a larger diameter lifters. The larger the more aggressive you can be with the cam. I remember mushroom lifters from way back in the day.. What is the reasoning behind Mopar cam grinds used in GM cams? I've seen some Olds guys say they use Mopar profiles.
the opening ramp is where a big dia lifter has an advantage, once past approx .170” to .200 lifter rise, there is no advantage, the lifter diameter becomes irrelevant past that point.
the quicker you can open the valve is a benefit because it can delay the reversion back into the intact tract. That hurts power at all rpm’s.
as rpm’s rise, it gets more difficult to control aggressive ramp lobes , so they tend to be less aggressive as rpm’s rise. On the bb Olds when you want to make as much power as you can with a flat tappet, bigger diameter lifters and aggressive ramp rates are always better.
You also have to pay attention to lifter face chamfer. Some lifters come with very large edge chamfers which reduces the diameter .
.017” is the distance I’ve been told is how close the lobe can come to the edge.
#55
That sounds about right, from what I recall. Thank you for providing the details.
You had the correct idea about the mushroom lifters and DUH filled in the missing details.
The "Hemi grind" profile can be put on any cam blank with enough material to grind. My step brother has a "Hemi grind" cam in his wedge head 383 Mopar. I believe I have either seen or heard someone putting an "LS" profile on an Olds cam.
Valve lifters are generally ground using a 40 inch radius on the bottom. One cam grinder will "resurface" lifters using a 36 inch radius on the bottom. This would allow faster opening ramps without scuffing the cam with the edge of the lifter.
Now come the comments.......
You had the correct idea about the mushroom lifters and DUH filled in the missing details.
The "Hemi grind" profile can be put on any cam blank with enough material to grind. My step brother has a "Hemi grind" cam in his wedge head 383 Mopar. I believe I have either seen or heard someone putting an "LS" profile on an Olds cam.
Valve lifters are generally ground using a 40 inch radius on the bottom. One cam grinder will "resurface" lifters using a 36 inch radius on the bottom. This would allow faster opening ramps without scuffing the cam with the edge of the lifter.
Now come the comments.......
lifter crown does not dictate opening ramp profile.
#56
Yes, the lobes don't care what engine they are in. That was the point I was trying to make.
#57
I wasn't thinking it would affect the opening or closing ramp profile. I was wondering if they would use a smaller radius to make the lifter edge higher and not scuff the cam. What are your thoughts ?
Yes, the lobes don't care what engine they are in. That was the point I was trying to make.
Yes, the lobes don't care what engine they are in. That was the point I was trying to make.
mixing and matching cam and lifter manufacturers sometimes can lead to wiped out lobes because of minor differences in lobe taper and lifter crown between manufacturers.
When the lifter crown, lobe taper and lifter bore offset to lobe centreline is all correct…big aggressive lobes with .921” lifters can last a very long time
one other thing that causes issues in Olds is using a bronze aftermarket cam thrust washer without back cutting the cam to compensate for the added washer thickness.
what that does is it moves the cam forward in the block while simultaneously taking away the offset to rotate the lifter
#58
lobes are ground with a taper to match the lifter crown to promote rotation. Changing the crown can screw that up .
mixing and matching cam and lifter manufacturers sometimes can lead to wiped out lobes because of minor differences in lobe taper and lifter crown between manufacturers.
When the lifter crown, lobe taper and lifter bore offset to lobe centreline is all correct…big aggressive lobes with .921” lifters can last a very long time
one other thing that causes issues in Olds is using a bronze aftermarket cam thrust washer without back cutting the cam to compensate for the added washer thickness.
what that does is it moves the cam forward in the block while simultaneously taking away the offset to rotate the lifter
mixing and matching cam and lifter manufacturers sometimes can lead to wiped out lobes because of minor differences in lobe taper and lifter crown between manufacturers.
When the lifter crown, lobe taper and lifter bore offset to lobe centreline is all correct…big aggressive lobes with .921” lifters can last a very long time
one other thing that causes issues in Olds is using a bronze aftermarket cam thrust washer without back cutting the cam to compensate for the added washer thickness.
what that does is it moves the cam forward in the block while simultaneously taking away the offset to rotate the lifter
#59
one other thing that causes issues in Olds is using a bronze aftermarket cam thrust washer without back cutting the cam to compensate for the added washer thickness.
what that does is it moves the cam forward in the block while simultaneously taking away the offset to rotate the lifter
what that does is it moves the cam forward in the block while simultaneously taking away the offset to rotate the lifter
#60
#61
i can have the cam back cut on its thrust face in 15 minutes. It’s takes longer than that to get block set up on a mill.
#62
#63
#64
#65
#66
#67
Why are liners required when increasing lifter bore diameter?
would the larger lifter also not aid in spreading the load out especially with performance high pressure valve springs?
Last edited by Bernhard; December 7th, 2022 at 11:01 PM.
#70
I said the discussion is irrelevant because 98% of people building serious Olds engines aren't going to do it. I can see Chad and Dale trying to squeeze every last drop out, but most won't. Those are also dyno and race engines. How is the durability on the street?
It's just like the 4/7 firing order swap. The cams are on the market, but if it's so great, why isn't it common place?
AND, it's a sidebar to Mark's thread about bringing another hydraulic roller lifter to market.
It's just like the 4/7 firing order swap. The cams are on the market, but if it's so great, why isn't it common place?
AND, it's a sidebar to Mark's thread about bringing another hydraulic roller lifter to market.
Last edited by fleming442; December 8th, 2022 at 03:37 AM.
#71
Weren't mushroom lifters used for class or racing with cam restrictions? It was just another way to squeeze out every last HP in those situations. If that's true, then no need for a "no rules" engine like a street motor.
#72
Super stock might have been allowed mushroom lifters?
#73
I said the discussion is irrelevant because 98% of people building serious Olds engines aren't going to do it. I can see Chad and Dale trying to squeeze every last drop out, but most won't. Those are also dyno and race engines. How is the durability on the street?
It's just like the 4/7 firing order swap. The cams are on the market, but if it's so great, why isn't it common place?
AND, it's a sidebar to Mark's thread about bringing another hydraulic roller lifter to market.
It's just like the 4/7 firing order swap. The cams are on the market, but if it's so great, why isn't it common place?
AND, it's a sidebar to Mark's thread about bringing another hydraulic roller lifter to market.
Your right 98% will not go to this level of detail. But I find it interesting to see how detail oriented and creative performance minded engine builders are.
#75
I said the discussion is irrelevant because 98% of people building serious Olds engines aren't going to do it. I can see Chad and Dale trying to squeeze every last drop out, but most won't. Those are also dyno and race engines. How is the durability on the street?
It's just like the 4/7 firing order swap. The cams are on the market, but if it's so great, why isn't it common place?
AND, it's a sidebar to Mark's thread about bringing another hydraulic roller lifter to market.
It's just like the 4/7 firing order swap. The cams are on the market, but if it's so great, why isn't it common place?
AND, it's a sidebar to Mark's thread about bringing another hydraulic roller lifter to market.
#76
I don't know all the pricing, but it doesn't seem like an economical solution by the time you get the bores bushed, find suitable lifters, and have a cam ground to take advantage.
#77
Yes it cost to modify the block to accept larger lifters for sure. My point is/was that a larger diameter lifter was advantagous when using a more aggressive cam. I guess the best way to put it is you can use a more aggressive cam with a .921 lifter versus a .842. I know @ one time finding roller lifters for a .921 bore was very limited and only certain lift cams could be used. They why I said lifter diameter matters when selecting a cam.
#78
Not sure I would agree with the above ststement! As with this engine platform, there is nothing a cam can't do with .842 that a bigger lifter can. HARD TO PUT THIS INTO WORDS THAT WON'T OFFENED PEOPLE. But for a 900Hp OLDS engine, there more in the cam and pushrods then there is in a lifter. 99% of the info about the lifter is just advertisement and upselling.
I run .842 roller lifter over 10,000RPM on a 55mm cam core and 1/2" double taper pushrods. I had a very good and long discussion with MR. Gene FULTON about using a larger lifter in one of my big motors for the street. Is it a better deal? YES Gene said, but HE wasn't sure it was worth the $$$ for a 70% street motor. As Gene said, "we have used .842s for years with success!"
I run .842 roller lifter over 10,000RPM on a 55mm cam core and 1/2" double taper pushrods. I had a very good and long discussion with MR. Gene FULTON about using a larger lifter in one of my big motors for the street. Is it a better deal? YES Gene said, but HE wasn't sure it was worth the $$$ for a 70% street motor. As Gene said, "we have used .842s for years with success!"
#79
Not sure I would agree with the above ststement! As with this engine platform, there is nothing a cam can't do with .842 that a bigger lifter can. HARD TO PUT THIS INTO WORDS THAT WON'T OFFENED PEOPLE. But for a 900Hp OLDS engine, there more in the cam and pushrods then there is in a lifter. 99% of the info about the lifter is just advertisement and upselling.
I run .842 roller lifter over 10,000RPM on a 55mm cam core and 1/2" double taper pushrods. I had a very good and long discussion with MR. Gene FULTON about using a larger lifter in one of my big motors for the street. Is it a better deal? YES Gene said, but HE wasn't sure it was worth the $$$ for a 70% street motor. As Gene said, "we have used .842s for years with success!"
I run .842 roller lifter over 10,000RPM on a 55mm cam core and 1/2" double taper pushrods. I had a very good and long discussion with MR. Gene FULTON about using a larger lifter in one of my big motors for the street. Is it a better deal? YES Gene said, but HE wasn't sure it was worth the $$$ for a 70% street motor. As Gene said, "we have used .842s for years with success!"