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post #61 of 221 (permalink) Old Mar 30th, 19, 6:31 PM
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Re: Overdrive and camshaft selection

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Originally Posted by William Hennke View Post
Vacuum on mine at 900 RPM is 11Hg with 18* initial and 15* vacuum advance. Thinking about locking the advance out this weekend and trying it but I'm sure it won't fix it. I just as well plan to change yet another cam. I have a cam on the shelf I can have reground. I wonder who can regrind my 241/251 @ .050 637/612 112 LSA cam? If I can take 10 degrees out of it I would think it would work good?



I would just send it back to the manufacturer for a regrind.

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post #62 of 221 (permalink) Old Mar 30th, 19, 8:35 PM
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Quote:
Originally Posted by William Hennke View Post
Vacuum on mine at 900 RPM is 11Hg with 18* initial and 15* vacuum advance. Thinking about locking the advance out this weekend and trying it but I'm sure it won't fix it. I just as well plan to change yet another cam. I have a cam on the shelf I can have reground. I wonder who can regrind my 241/251 @ .050 637/612 112 LSA cam? If I can take 10 degrees out of it I would think it would work good?



I would just send it back to the manufacturer for a regrind.
I don't think they can take that much off that cam without going through the hardened surface. And the cam that's in it now is on a 107 LSA so I don't think it can be reground to a 110 or 112 LSA.


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post #63 of 221 (permalink) Old Mar 30th, 19, 9:31 PM
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Re: Overdrive and camshaft selection

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Originally Posted by -SS454- View Post
Wider LSA's typically reduce overlap. I've heard of large overlaps creating some issues with o2 readings, but I've never seen any back to back tests personally. Then there is the vacuum issue it can present as mentioned already. Not to say tighter LSA's can't work, but generally speaking I would stay away from them on an EFI build. I suspect an EFI tuner may have the best knowledge of the challenges presented by a tighter LSA. But I'd assume there is a reason why EFI engines typically get a wider LSA than carbureted engines.
I run this cam in my 468 w/ EFI

https://www.howardscams.com/hydrauli...cams-121905-08

I DD a diesel and am use to low RPM's, so I normally shift to early and run RPM lower than what most people would, but I can pull from around idle in 3rd or 4th gear (only a 4 speed), cruise at low rpm and have zero issues with bucking or anything. Timing is 18* at idle and 38* all in at 2400 rpm

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post #64 of 221 (permalink) Old Mar 31st, 19, 12:38 AM Thread Starter
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Re: Overdrive and camshaft selection

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I run this cam in my 468 w/ EFI

https://www.howardscams.com/hydrauli...cams-121905-08

I DD a diesel and am use to low RPM's, so I normally shift to early and run RPM lower than what most people would, but I can pull from around idle in 3rd or 4th gear (only a 4 speed), cruise at low rpm and have zero issues with bucking or anything. Timing is 18* at idle and 38* all in at 2400 rpm
Do you have a video of that cam? What vacuum are you running with that? That is something I am looking for.
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post #65 of 221 (permalink) Old Mar 31st, 19, 7:33 AM
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Re: Overdrive and camshaft selection

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I run this cam in my 468 w/ EFI

https://www.howardscams.com/hydrauli...cams-121905-08

I DD a diesel and am use to low RPM's, so I normally shift to early and run RPM lower than what most people would, but I can pull from around idle in 3rd or 4th gear (only a 4 speed), cruise at low rpm and have zero issues with bucking or anything. Timing is 18* at idle and 38* all in at 2400 rpm
Once you get into 5th gear/OD your transmission is giving the engine A LOT less mechanical advantage vs the 1st 4 drive gears. Combine that with the drop in torque that larger cams produce at low rpm and you could have an issue.

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post #66 of 221 (permalink) Old Mar 31st, 19, 11:44 AM
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Re: Overdrive and camshaft selection

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Originally Posted by 69-CHVL View Post
The cams that everybody says sucks - Comp Xtreme Energy

Basically this cam with a smidge less exhaust duration and on a steel core.

https://www.summitracing.com/parts/c...make/chevrolet

May I ask what is your vacuum and idle speed? A cam on a 107 I assume will have alot of overlap which at low rpms will have reversion which will may create tuning issues. But IMO, your trans 4-5th drop is the biggest challenge - trying to cam around that.




If you have a T56 you can go a little bigger on the cam b/c the 5-6th gears will allow the engine to be in a happier place vs the TKO .64 which has a 1000 rpm drop between 4-5th gear. If your engine has a large cam with alot of overlap, it isnt going to like it too much. But for a street 454 I wouldnt go bigger than 230. Your just trading away torque and snappiness with anything bigger for no f'ing reason.
Not surprised its a comp cam, i used several and never a problem. Comp often get bashed, but remember they are biggest aftermarket cam company. Do you think his 540 will swollow little more cam? Or would you recomend op same cam as you are using?

Op wouldnt try to regrind any of the old cams theres a big risk you get into soft metall, Belive a comp on billet core with cast gear is 400-425$ and they use Us made cores, same cam core from the fancy custom cam companys are close to 600$ and you already been there? Tried to get them exchange you a cam that fits your need better since they was way of with what they sold you?
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post #67 of 221 (permalink) Old Mar 31st, 19, 12:50 PM
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Re: Overdrive and camshaft selection

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Originally Posted by Chevelle 1969 View Post
Not surprised its a comp cam, i used several and never a problem. Comp often get bashed, but remember they are biggest aftermarket cam company. Do you think his 540 will swollow little more cam? Or would you recomend op same cam as you are using?

Op wouldnt try to regrind any of the old cams theres a big risk you get into soft metall, Belive a comp on billet core with cast gear is 400-425$ and they use Us made cores, same cam core from the fancy custom cam companys are close to 600$ and you already been there? Tried to get them exchange you a cam that fits your need better since they was way of with what they sold you?

Any engine will "swallow" more cam - on the dyno its easy to see that. What doesnt get swallowed IMO is all the crap that goes along with the bigger cam: lower vacuum, higher idle speeds, low rpm tq loss. I can only tell folks what I run and what has worked for me after alot of trial and error. I believe the T56 will solve just about any drive-ability issue, but with the TKO .64 you have to make some compromises if you run it around town in 5th gear.

Just for kicks I'd like to try a 216/220 HR to see if I could still crack 120+mph...how cool would that be.

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post #68 of 221 (permalink) Old Mar 31st, 19, 1:02 PM
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Re: Overdrive and camshaft selection

Perfect example of a hot street 454 dyno test with a 222/230 and 234/242 HR and then the same cam with single planes. Look at the low end of the tq curve where you spend 99% of the time:

https://www.hotrod.com/articles/crane-cams-dyno/


*69 SS 502 EFI /224* HR/9.8:1/T56/3.90 11.5/124mph
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post #69 of 221 (permalink) Old Mar 31st, 19, 2:57 PM Thread Starter
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Perfect example of a hot street 454 dyno test with a 222/230 and 234/242 HR and then the same cam with single planes. Look at the low end of the tq curve where you spend 99% of the time:

https://www.hotrod.com/articles/crane-cams-dyno/

Man I guess I need to drop a cam size... 234/240 seems like best bet. I get a cam recommendation from Jones cams and this is what it came to. I'm really curious how LSA affects a bigger cam.

241/251 @.050"
.375"/.360" Lobe Lift
.637"/.612" Valve Lift
112 LSA
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post #70 of 221 (permalink) Old Mar 31st, 19, 3:10 PM
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Re: Overdrive and camshaft selection

Following this thread. But Jones seems to have a good following
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post #71 of 221 (permalink) Old Mar 31st, 19, 3:20 PM Thread Starter
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Following this thread. But Jones seems to have a good following
If you're following me, it'll be a little while before I get the t56 in(this summer sometime I hope)
I wanted some input on cam size as I'm afraid mine is too large to deal with OD
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post #72 of 221 (permalink) Old Mar 31st, 19, 4:49 PM
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Re: Overdrive and camshaft selection

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Originally Posted by tacomatrd View Post
I guess my next project will be swapping to another cam.
I will probably go with a custom roller, but in all honesty I want something in the 230/236 range on a 112 with around .600 lift. I think it would give me a little broader torque range and better driveability with a stick. Of course I will try with my current cam firs though.
As for my cam on a 108 and the duration it has, I make around 6 inches of vacuum.



Isn't that only if the torque converter isn't passed stall speed? Otherwise it is just slipping and creating heat. If you are able to pull 2.87s and a stock stall, you really can't compare your set up with a performance engine. Two whole different beasts
Most manufacturers of Over Drive Automatics recommend a lock up converter if running a final drive higher than 3.55.

On my TCI 6x, The lockup is darned near a 7th gear. I rigged a switch where it will stay in lockup on the htway all the time. With the 3000 stall converter, it is annoying feeling it go in and out. The 540 has so much torque I can leave it in lockup.

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post #73 of 221 (permalink) Old Mar 31st, 19, 9:01 PM
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Re: Overdrive and camshaft selection

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Originally Posted by tacomatrd View Post
Do you have a video of that cam? What vacuum are you running with that? That is something I am looking for.
Ill get you one, I dont have one with the new cam nor have I put the vacuum gauge on it, Ill do that as well.

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73 CJ-5 with a 468 BBC 10:1, 265 AFR's, Sniper EFI. The wheelie machine
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post #74 of 221 (permalink) Old Mar 31st, 19, 9:12 PM
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Re: Overdrive and camshaft selection

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Originally Posted by tacomatrd View Post
Man I guess I need to drop a cam size... 234/240 seems like best bet. I get a cam recommendation from Jones cams and this is what it came to. I'm really curious how LSA affects a bigger cam.

241/251 @.050"
.375"/.360" Lobe Lift
.637"/.612" Valve Lift
112 LSA
Very close to what I ran in the 540" (242/249, .650/.650, 112LSA). Idled around 900 neutral, 800 in gear. Ran a low stall 10" converter (2900 stall).

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post #75 of 221 (permalink) Old Mar 31st, 19, 9:53 PM Thread Starter
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Originally Posted by tacomatrd View Post
Do you have a video of that cam? What vacuum are you running with that? That is something I am looking for.
Ill get you one, I dont have one with the new cam nor have I put the vacuum gauge on it, Ill do that as well.
Sweet thank you!

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Quote:
Originally Posted by tacomatrd View Post
Man I guess I need to drop a cam size... 234/240 seems like best bet. I get a cam recommendation from Jones cams and this is what it came to. I'm really curious how LSA affects a bigger cam.

241/251 @.050"
.375"/.360" Lobe Lift
.637"/.612" Valve Lift
112 LSA
Very close to what I ran in the 540" (242/249, .650/.650, 112LSA). Idled around 900 neutral, 800 in gear. Ran a low stall 10" converter (2900 stall).
How did you like it?
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