Unless the race car engine is being redone/redesigned, it’s all about having fun and trying things.
Stroker specific cams?
- Thread starter DrEamer
- Start date
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j par
Well-hung Member
Or perhaps he is just having fun?!?!
I think you both got it...
But J par, your throwing HP and TQ out the window like the IS government throws money at problems!!
What will you ever do?!?!
Oh the shame! The heartbreak, the constant badgering you’ll get endlessly from the know everything crew!!!
GOD forbid you use a.. a.... a... THERMOQUAD!!!
OMG!!!
What will you ever do?!?!
Oh the shame! The heartbreak, the constant badgering you’ll get endlessly from the know everything crew!!!
GOD forbid you use a.. a.... a... THERMOQUAD!!!
OMG!!!
j par
Well-hung Member
I try my best to have the bench racing Wars on the bench racing threads...
DrEamer
I suffer from cars on the brain!
Hopefully we can get this thread back on track, if you want to bicker at each other, then PLEASE get out of my thread!!! There has been a lot of great info, let's get back to that.
Now to address the quote above.
My magnum block is an early transition year, so yes, I can use either pushrod oiling, or shaft mount. B3 says that I can use the PRW rockers if I want, and just use pushrod oiling. He also recommends blocking off the LA oiling to the shafts if that is what I do. I'm not sure the is an advantage of one over the other, but it is nice to have the choice.
@jpar
I called oregon Cam Grinders a few weeks ago, but did not talk to Ken. The cost is $325 since I have to start with new pieces. At that price, it is not a big savings, but I like the idea that is a 90 mile drive if I need something. He will get a call at some point.
Mopar Tech
Well-Known Member
I haven't read much of this thread but see several things repeated that are flat out wrong. If you want a great cam call Tim at Bullet cams and forget the internet theorists. Just to much wrong info being spewed. You could contact me by PM but I don't feel like dealing with this BS storm,it's not like most cam posts end up up better. LOL
Back in business.
DrEamer
I suffer from cars on the brain!
I want to thank Mike for opening this tread back up. He took it upon himself to clean up the bickering without me reporting anything. Everyone is welcome to post here, please just keep it civil, and on subject. I have received PM's from a couple of members with apologies, for which I am grateful. Probably not needed, but grateful. Now with that is out of the way, let's get back at the subject at hand !!
So, I had looked at some stroker builds from Performance Injection Equipment some time ago. They are big into the Dodge Dakota racing/modification seene which use the Magnum series engines. They use the ported EQ cylinder head which have good flow. He told my that they used Bullet, and Comp to custom grind cam for them. It is interesting that they use slightly different cams for the LA carb based and Magnum injected based crate engines. Below are the specs, with their dyno results.
Carb cam: Hydraulic roller, duration @ .050: 224 / 230, lift: .565"/.565" 110 LSA
470 bhp@ 5,400 Rpm
520 btq @ 4,400 Rpm
Injected cam:Hydraulic roller, duration @ .050: 226 / 230, lift: .565"/.565" 110 LSA
Dyno Test Results
470 bhp@ 5,100 Rpm
512 btq @ 4,300 Rpm
nm9stheham
Well-Known Member
And I won't spend long on this.... but that goes back to application. I don't drag race... I rally (well, I drove rally cars...been a while now). Excess torque over a very wide RPM range is important because with 500 turns on a rally stage that are all different, you're gonna hit some gear-speed combo's where a narrow torque band engine is not going work. (BTDT! Young and dumb LOL) You need excess torque in a turn NOW to get the drive wheels spinning/slipping as part of steering the car on loose gravel (think of sprint cars only worse!). You can't wait even a fraction of a second 'til the engine rev's up a few hundred RPM; the brain-to-throttle-to-drive-wheel-spin/slip has to be an instantaneous connection to go fast.
Best flow and HP means very little to nothing if you don't have the necessary excess wheel torque over a wide range in that application. If your torque range reaches down another 500 RPM or more, it is truly golden in that kind of use.
Not criticizing anyone or any use... just trying to explain why the performance emphasis will vary. I see spirited street driving on curvy roads much more like rallying than drag racing. FWIW.....YMMV and all that good stuff, and may not be at all applicable for the OP's use.
Boy, if those two grinds ain't splittin hairs, I don't know what is. lol
DrEamer
I suffer from cars on the brain!
True, but nice to see someone who has some tested options. The below cam is another option that he has. I copied to whole description for since it relates to your earlier post about lobe separation angles.
Duration @ .050 230 / 236
Lift .565" / .565"
This is a real good choice for more of a street / strip camshaft. It can still be toned down if it will be primarily used for a street driver. Just select the 114 degree lsa. The cam will work well with a looser converter and about 10.0:1 compression ratio.
Lobe Separation Angle Description
114 degree lsa provides smooth idle quality and provides a broad power curve. Engine vacuum will be increased. A wide lsa is a good choice for most forced induction applications. While a wide lsa does give a broad power curve it does reduce overlap which also reduces power. LSA is not as critical in smaller cam durations since the smaller cams do not have much overlap to start with.
112 degree lsa provides a slightly more noticeable idle over the 114 lsa. A slight power increase is possible with a tighter lsa due to the increase in overlap. 112 degree lsa also works well for a supercharged application
110 degree lsa provides a very noticeable idle. Power will be increased from the increase in overlap. Engine vacuum will be reduced from the overlap.
Duration @ .050 230 / 236
Lift .565" / .565"
This is a real good choice for more of a street / strip camshaft. It can still be toned down if it will be primarily used for a street driver. Just select the 114 degree lsa. The cam will work well with a looser converter and about 10.0:1 compression ratio.
Lobe Separation Angle Description
114 degree lsa provides smooth idle quality and provides a broad power curve. Engine vacuum will be increased. A wide lsa is a good choice for most forced induction applications. While a wide lsa does give a broad power curve it does reduce overlap which also reduces power. LSA is not as critical in smaller cam durations since the smaller cams do not have much overlap to start with.
112 degree lsa provides a slightly more noticeable idle over the 114 lsa. A slight power increase is possible with a tighter lsa due to the increase in overlap. 112 degree lsa also works well for a supercharged application
110 degree lsa provides a very noticeable idle. Power will be increased from the increase in overlap. Engine vacuum will be reduced from the overlap.
DrEamer
I suffer from cars on the brain!
You know honestly that is closer to the driving I will do. Living in Oregon means going over either the Coast or Cascade Ranges with a lot of corners and hill sections While cam selection important to torque production, the one thing 408's are known for is a wide torque curve. The cam only dictates where it occurs at most. Also, I'm not sure having the torque coming on higher in the RPM range is a bad thing, as a lot of torque down low can lead just blowing off the tires. I could be wrong on that though.
mullinax95
Well-Known Member
You might be interested in Hipotek's cams. I have ran two.. one for NA 408 and now a supercharged 408. Both cams utilizing fuel injection. The NA cam was a Comp XFI 230/236 .576/.571 on a 108LSA. Tuner was able to tune my PCM to work with the 108LSA. I asked first before buying the cam and he said it would be no problem. Never noticed any brake issues since I have power brakes or any EFI issues.
Had plenty of torque down low and horsepower up in the high revs. Fairy rough idle. My shift points are set at 6200 RPM. This cam worked great! This is in a 03 reg cab dodge ram. Never have dynoed it but want to.
IMM engine
EQ heads/PAC beehive springs
EFI intake
long tube headers
58mm throttle body
PRW roller rockers
Full forged rotation assembly
Had plenty of torque down low and horsepower up in the high revs. Fairy rough idle. My shift points are set at 6200 RPM. This cam worked great! This is in a 03 reg cab dodge ram. Never have dynoed it but want to.
IMM engine
EQ heads/PAC beehive springs
EFI intake
long tube headers
58mm throttle body
PRW roller rockers
Full forged rotation assembly
DrEamer
I suffer from cars on the brain!
Thanks for the info, I just went over your build thread which leads me to a few questions. How long did you run the XFI cam? I am a little concerned with their long term durability of the springs with the aggressive ramps. Brain noted earlier in this thread that he though the ramps made the valve train noisy, so wondering about that as well. Last question, are you still running the melling lifters, and how are they holding up if they are still in the truck. I had contacted Richard awhile back, so he is on my radar as well as an option.
Oh absolutely! I will admit, if I had a dyno up my ***, I would test cams for my combo until I got the one with the most power......but I have to make my best guess. lol
And unless you are NHRA class racing, who gives a rip about "maximum horsepower". 9 times out of 10 you sacrifice horsepower for torque at a certain RPM. You can build a big power engine and put it in a car with the wrong converter, rear gear, or tire size and it is almost worthless. THere again, on the dragstrip it's different. On the street it can be a waste.
The point I constantly try to make......yet get run over by a freight train(s) every single time.
Oh you mean those brow beater trains that shake you to high heaven......
yellow rose
Overnight Sensation
Who is talking about max HP. That's something that's being made up.
Look at nm9's post. There are times when killing low end power is the goal. Traction limited cars, most of the circle jerk guys at the local level think they are chassis gurus but an average engine builder can build enough power that the heroes can't make them hook on the best days.
LSA isn't about peak HP. I'm talking about under the curve power, which is what the street driving guys sqeal about constantly.
Using LSA to change idle is crazy. In fact, I'll say it's stupid. Here's why.
You must reduce duration to open the LSA up, otherwise the engine will hold power past peak way too long, and you give up a TON in the middle and lower middle of the power curve doing that.
If some can dude tells me a cam that has been cut on a 110 LSA has a rough idle I just hang up the phone and move on.
I've posted this before and it's still true today.
110 is the de facto LSA becuse Comp wanted it that way. Buying as many cores as they do, the 110 will fit on every core without issues. They can pull the cores out that will go down to 104 and up to 114 and use them when they need.
That's the FACT. It's not a speed secret. Jamora from Isky has written about this. So it's not like it's hidden.
To compromise valve timing events to get the LSA you want is crazy. Just crazy.
The guys who don't or can't test always pull out the max HP card. It's because you don't know what you are losing.
IDGAF what engine or class we are talking about, there will be only a few different timing event sets that will work. That depends on the agressiveness of the lobe, intended use, traction potential (or lack of it), induction and maybe two other things. I'm not considering overall air flow or any of that.
Once you have that information, you'll see that any deviation from the required duration to achieve PEAK power at the RPM required will kill power everywhere if you manipulate the LSA to affect characteristics that should be left alone.
That's wasting power. Not peak power either.
nm9stheham
Well-Known Member
There you go.....you are thinking right. On dirt and gravel and pavement, you can often 'modulate' the steering with torque changes, and you want some excess torque to be able to modulate around that point. In highway driving you are not under the same time pressure to want to avoid a gear shift if you fall out of the excess torque RPM range. It gets more critical if you are racing, especially on the hairy edge. I could go on ad nauseum upon the subject, but you obviously get it and can make the trade off.
nm9stheham
Well-Known Member
This has been in the back of my mind since this thread started: Should fuel mileage be thrown into the mix of trade-offs? OP? What is OK?
nm9stheham
Well-Known Member
But, but, but.... that is what the Thumpr cams do..... oh wait, that IS stupid LOL.
The 2nd part took me a while to grasp.... but I assume you mean that since the wider LSA moves the exhaust pull-through RPM's up, then the same duration moves the whole RPM band up...but you'll hit the physical RPM limits of the engine (oiling limits or valvetrain float) and have a narrow RPM range due to that. Is that right?
yellow rose
Overnight Sensation
Yes. And a wider LSA will hold power much longer after peak. That's why you see wider LSA numbers for a powerglide car than you would with a TF or some other 3 speed auto. Add in a 4 speed or better yet, 5 gears and you can move the timing around and get the power to fall off past peak like a cliff.
I wish I would have exercised my patient muscle when I did my engine. I just got tired of it and skipped the dyno. I broke my own rule. Now I'm paying for it.
My *** dyno says I make peak power somewhere around 6700ish. By 7100 it's all over but paying the dude his money because if I over rev it, it falls on its face. Not from valve float, just the power curve falling off the edge of the world (a little Sabbath reference for the older crowd).
As because my LSA fell at 105 and I said leave it IF it won't change the curve in the middle. Jim (at Racer Brown) said it just won't pull past peak very much.
So I either need to nail the shift points (which adds complication to clutch tuning) or it will be dead slow.
So that's what I'm trying to get across. Evidently, for the most part, I'm failing.
I'd rather get the cam timing where it needs to be, and let the LSA fall where it is, than to move the timing around to achieve some perceived need. It's almost never about peak power. It's under the curve.
The other thing, like all tools, the dyno has its limits. A water break dyno (as opposed to an inertia dyno) controls the rate of acceleration. IOW's, a water break dyno can't measure an engines ability to Rev. And if you think about it, the ability to RPM, to pull back from the shift point is all that and then some. Even driving on the street. And low throttle openings. Since the WB dyno can't measure that one really important statistic, you can get fooled.
I've spent some time on an inertia engine dyno. In fact, I worked for a fat, lying, thieving SOB that let me order what became the Revoltution Dyno and then screwed everyone including his mother and then ran to New York like the criminal he is. So I've spent time with different dyno's and you need to know the limitations of each.
mullinax95
Well-Known Member
It wasn't very long. I can't remember right off hand but I think it was 6 or 7 months.
I don't know the noise Brian is talking about... I didn't hear anything unusual. I have PAC beehive springs so I they might help keep down the vibes and noises. Just guessing on that.
They are doing well. There is no clatter until the oil pressure builds up like the old lifters.
DrEamer
I suffer from cars on the brain!
Fuel mileage is not a true concern for me. I figure if it gets 12-14 mpg then I'll be fine. I hope for more with the overdrive transmission, but fun per mile is more what I am looking for.
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