Ok, you’ll have to help me out here.
Why is the “kit” part of it such a game changer for you? If you take your time and look around you can pretty much the same stuff. Not sure what’s in the kit, but you don’t need a garage door slamming valve spring or double tapered pushrod (and everyone knows I love those things but you just don’t need them).
So you need a cam, the lifters (there is only a couple of lifter manufacturers out there so whatever name is on the box means pretty much nothing) and a decent single spring for what you want. Nothing trick or special there. You can use a stock rocker and probably use your pushrods.
Lots of junk is popular on the old interweb, doesn’t mean it’s worth a crap. Most guys never test much of anything and they buy based on marketing hype and “testimonials” from guys who’ve never used anything else. And they’ve bought into decades old myths that never die.
Not sure how changing the LSA complicates other components. If you ***** at Comp enough they can grind that cam you like on a 106 or 108. I wouldn’t do that but you can. I’m it sure what that complicates.
I’m not bagging on you, I’m trying to understand your thought process. I will give you my thinking on why I don’t like the grind you do, besides the fact that a kit never got me excited.
The first thing that I see is that lobe was designed for an .842 lifter. GM sizing. What that means is the lobe was designed so that the smaller diameter lifter won’t dig into the side of the lobe if the grind gets too aggressive. Obviously we are taking street lobes here so that scenario doesn’t matter, but thinking about how a lobe is designed and what you give up. Seat to seat timing is a power killer, and the slower lobes have more seat to seat timing for the same, or less at .050 timing. You give up low end doing that, and that’s where most street guys want their power. It shows up in drivability.
So let’s look at the Comp lobes first. It is lobe number 5442. The lobe is 262 at .006, 218 at .050, 130 at .200, .308 lobe.
The Comp exhaust lobe is number 5201. The lobe is 270 at .006, 224 at .050, 133 at .200, .313 lobe.
I’m not a big fan, and probably never will be of gasoline burning N/A engines with headers using more exhaust duration than intake duration. On alcohol burning engines I like some split. But not on gas. The cam grinders do this because they are compromising. They assume you can’t tune, can’t learn to tune and therefore the literally dumb the cam down for you. Call a cam grinder doing this and ask them if they are using less intake duration or more exhaust duration. I say they use less intake duration. Then, to get the high RPM limit where they want it, the open the LSA up. And boom, you just killed the middle of the power band right where most guys want it. You can have a bit smoother idle that way, but you lose so much drivability it’s crazy. This stuff gets marketed as better than sliced bread. IMO it’s not.
Let’s look at the Howard’s lobe. I’d use the same lobe on the intake and exhaust. It’s 271 at .006, 224 at .050, 144 at .200, .345 lobe.
Now compare that to the Comp exhaust lobe because it won’t really compare to the Comp intake lobe.
That Howard’s lobe is one degree bigger at .006 lift, 270 for the Comp, 271 for the Howard’s. By .050 lift both lobes are at 224. Look at what happens next. The Comp lobe is 133 at .050 lift, but the Howard’s lobe is kicking its *** at 144 degrees at .200. What that means is that both lobes have the exact same timing at .050 lift but the Howard’s lobe is 11 degrees bigger at .200 lift!!! That’s exactly what I look for. Less or at least the same seat to seat timing with the same or bigger number at .050 lift and a bigger number at .200 lift.
We could get into L/D ratios, where flow really happens in the port and how it relates to rod to stroke ratio but it doesn’t really matter. Any time you can use the same or less seat to seat timing with quicker at .050 and .200 numbers you will have a fatter torque curve and more power everywhere. And you don’t give up anything.
That’s why I harp on this stuff. It’s the details that matter. A small change in cam timing can pay huge dividends all over the power curve. But marketing hype sells more cams than actual tech does. As an aside, I read an article in an industry magazine about the guy who made the Dynojet chassis dyno. He was visiting shops trying to sell his dyno. One guy heard the price and laughed in his face. The funny thing was the dyno (at that time) was 25,000 bucks. The engine builder said he could sell way more engines using that 25k for marketing than he ever could buy the dyno. The dyno guy said he could verify what his engines did for power. The engine builder didn’t care. He said the customer didn’t know 400 from 500 horsepower, but he did understand advertising. Another aside...the first engine builder I used would hand out free T shirts to anyone who came in with you when you picked up an engine. You could go to the local track and see 100 people wearing his shirts and maybe 5 or 6 guys wearing them actually ran his engines. It looked like everyone and their mother had his engines. Brilliant marketing. He sold a ton of engines just because of the T shirt deal.
I mention all of that because big, glossy adds in every magazine there is, all the “sponsored” “tests” in magazines and YouTube junk is all part of the advertising business. Magazines make the vast majority of their profits from advertising. Subscriptions pay for the overhead and such, but advertising is the gravy. More subscribers means higher advertising rate, which means more profits to the publisher.
So...do we really think in any form of testing that is sponsored by an advertiser will show results detrimental to an advertiser with 3 or 4 pages of advertising?? Nope. You don’t poop in your own kitchen.
Now onto the LSA. I already touched on it, but the cam finders love to use the de facto 110 LSA for everything because...well...it’s a compromise and an economic decision.
When these cam grinders buy cores by the train car load they are not all the same. Where the lobes are placed on the core makes a difference on where you can grind the lobe. My personal cam is on a 105 LSA and it was a PITA to find a core that could support a lobe that would net .600 lift and be ground on a 105 LSA. So the 110 LSA is the best compromise for that. Almost every core will take a 108-112 LSA. Once you go more or less than that, it gets harder to find cores.
And the 110 is a compromise because most of the time you can still run power brakes with them. Start getting tighter than that and you can have issues. To eliminate that I just converted a 73 Duster to manual disc brakes and that thing stops better with a 280 duration solid on a 106 LSA than it ever did with power brakes and a dead stock 318.
Anyway, this post is now approaching AJ length. LSA is a big deal. If you reduce duration and then open up the LSA to keep the upper RPM end where you want it will kill power right where you want it. Overlap and the overlap triangle do a bunch to fill the cylinder. Narrowing and lowering the overlap triangle to crutch an RPM, idle or braking issue is always at the expense of the most useable part of the power curve.
I just want you to consider some of this stuff before you invest in a kit for simplicity sake. And for the record, I could look through the Comp Master Lobe Catalog and find a lobe that is the same or even quicker than the Howard’s lobe. I personally don’t like dealing with Comp.
Buy once, cry once I always say.