Agreed. But even in perfect tune, not everyone wants what that 108 gives.
Cam Experts: Lobe Separation Angle?
- Thread starter middleagecrisis
- Start date
-
Well of course. That just drives my point home even further. Race oriented = a tighter LSA.I put LSA to the test a few years back
My first W5 deal was slapping the heads onto an Eddie headed short block I was upgrading from.
11.5 compression flattop deal, 260/266 597/615 107 LSA cam. PHR did the cam. Flat tappet.
Car went 10.30’s like that.
Buddy at the time was/is a “ cam guru” who sells his own line of camshafts. He is way into wide LSA stuff.
He wanted me to swap to a cam he designed for ny deal, knowing exactly what I had going on.
It was 259/267 , similar lift as old one, but it was on a 112.
Took it to the track, all the incrementals were off, except the mph was very close.
Car never again got even in the 10.40’s, before I blew it up( Eagle cast crank) at the tail end of that season.
The 112 cam was like a shot of novacaine to how the car left. Doggy.
I suspect if I had WAY more compression, good bit more vert, and car wasn’t as heavy, the cam might have shined a bit.
But since then, everything I have run was on either 106 or 108.
No wide in my ride
Agreed, Why I generally argue this stuff generally comes down to each personal preferences, the right cam, head, carb etc... is heavily dependent on who it's for more then what it's for.
Newbomb Turk
Well-Known Member
I know that. You know that. What I do not know how to do is get all you types to agree with me!!!
This place would be a lot simpler then don’t you think?? Lol
"All you types?" lol
I tend to agree. Most every time it's "too much" cam that's the dog rather than "not enough". It's the same rule with carburetors. 99 times outta 100, you'll be happier with "less" carburetor than with "more".
To that line of thinking........
You ever seen any stock 340s that were dogs? I have not. There were none, unless there was something wrong with them or they were slam wore out. Even the 73 340s would haul the mail. Ever seen a HP 440 that was a dog? Again, unless there was something wrong with it, or it was wore out, nope. They'd rip it up. And BOTH the big and small block engines did it with 114 LSA for the small block and 115 for the big block. Wide LSA won't run? My *** it won't.
junkyardhero
Well-Known Member
i miss the old days when everybody bought carbs and cams like they were titties: the bigger the better! no nerd *** nerds talking about angles and duration. the only thing that mattered was lift and how big of a double pumper you had.
anyway, the answer here is clearly 3/4 race cam. it's worked for decades and it'll continue doing so long after we're all in the dirt.
anyway, the answer here is clearly 3/4 race cam. it's worked for decades and it'll continue doing so long after we're all in the dirt.
A lot of that last paragraph is that they had a box to work within.
Engineers chose a path. How do you think a 340 built to HP would have run with a cam similar to a 30/30 chevy solid. A 440 with a LS6 style solid? Would have been an entire different crying game from the bowtie crew. Being that the cams mopar chose were small in comparison, the LSA makes little difference.
Heck, we made all them horrible combos run bout good as they possibly could. Advance the cams, gave um gobs of initial timing. They ran purdy dang good for a stock motor with a cam. lol
Exactly my point. How many big block Chevelles you reckon were put on the trailer by 340s and 440s? A dang heap, I bet.
The Duntov cam was ground on a 112. Even still, those specs on a Mopar core in a 68-71 340 wouldda been pretty nasty.
So far every lsa shootout I've seen, seems to average around 3 lbs-ft per degree of lsa.
cookietruck
Well-Known Member
Possibly, I didn't notice that part of it, I'll looked them up and see/report back.
The ones I could find didn't seem to.
B3422w5
Well-Known Member
Track results and dyno results can and usually do differ.
My car that I mentioned earlier in the thread ran within half a mile per hour with the 106 or 112.
But the 106 was way way quicker. All the other incrementals were better.
Roughly tenth and a half difference.
I will always place track results way above dyno numbers.
I can pretty much guess, pretty darn close what any typical small block bracket car will make on the dyno if I have the combo particulars.
But I am often easily fooled by what a given car actually runs.
I don't see how this and my observation contradicts one another ?
Mph is far as I hear based on hp not torque.
106 vs 112 if the 3 lbs-ft per degree at peak holds true, be around 20 lbs-ft isn't that gonna help in all the areas you stated ?
I wasn't making a case for either way, was just stating what I've observed and not saying it holds as a general rule of thumb either.
Yes, usually more on the bottom. Wider LSA usually means flatter torque curve and stronger bottom end.....but again, it's splittin hairs. But that's what most dynos say.
I agree 100% about track results having priority. That said, if you're not racing it's a little different perspective.
That just tells you it had more usable power in the rpm range at use which is great if your selecting a cam for race. If you are looking at factors for the street you might make a different choice. Again, its intended purpose and it doesn't mean a narrow LSA is best.
Last edited:
B3422w5
Well-Known Member
For sure…and if I was no prep racing or was a guy who liked to terrorize the streets, the wide LSA would probably be the way to go because it’s going to make the car a good bit more soggy at the hit. Which is a good thing with bad traction or bad tires or both.
Newbomb Turk
Well-Known Member
LSA certainly can be a tuning tool. My thing is even a street/strip car should focus more on the chassis if it won’t hook rather than detuning it.
On the other hand, I’ve had to detune some engines just to get them qualifying for the B main.
So it goes both ways and as a tuner you have to get the car to make a pass or get around the track. And even get reasonable bite on the street.
Imagine running 11.8's with a 220 @ 50 hydraulic on a 114 LSA in full bodied street car around 3300 lbs. 351 with 2V's.......
Last edited:
"The rest of the car" a lot of times is overlooked in the quest for a fast/quick drag car. I knew a guy when I worked at the local Chevy dealer. Had a STONE STOCK 270 HP 350 in a 70 Nova. He's gone now, but he was a super cool old school racer and was still doing it and enjoying it with his 2 grown sons. That car was dead consistent in the mid 12s from what I remember. I think it may have even gotten some 12.30s. The car itself was set up right and yet it sounded like grandmaw's grocery getter. He said it was the most consistent car he had ever raced. He was always winning, too.
-
