Here is one of our other roller cam thrust plate test engines with the Howards 4-7 Swap CL514825-10 cam kit installed.
455 with 11:1 compression. This cam is described by Howards as having a "fair idle". I would say it should state "choppy aggresive idle" - we shall see how this behaves in the car before all too long:


455 with 11:1 Compression, Howards 4-7 swap roller cam - VERY aggressive engine

Here is a quick test run video to check out - turn your volume up and listen to this beast!
Howards CL514825-10 Cammed 455 with 11:1 compression

That's one heckuva choppy idle I didn't particularly see coming!

Paul...

 

Lemme guess: it's a 107ish....

 

Don’t let the sound on a run in stand fool you. This cam is very mild for a 11:1 455. It’s 225/229@.050 on a 110. Not big at all.

 

I always get a kick out of those stationary run stand videos with no weight at the crank. When the flex plate or flywheel get weight put behind them the idle will smooth out some what.

 

What correction factor have you been seeing this month?

 

About 4% on average.

 

There’s a shop here in Florida (Precision Engines I think) that posts videos of his builds on a run-in stand and he brags about the throttle response. They’re basically open header with nothing more than a 1 pound flexplate. They better be responsive!!!

 

Interesting.

 

NOTE: CORRRECTION OF POST TITLE LINE - I WAS MISTAKEN ABOUT THE LS FIRING ORDER (read the further additional posts below). With individual coil on plug cylinders or DIS twin coils, you don't think nearly as much about firing orders, so you essentially don't particularly burn firing orders into your brain like you used to with the earlier distributor based engines. My bad - whoops!

This cam was my first venture into swapping the firing order from the good ol' 1-8-4-3-6-5-7-2 to a revised 1-8-7-3-6-5-4-2. This seems to have changed the sound from that classic Olds melody to something different / unique. I have run many rollers with almost identical specs on the "old" firing order, finding them to be smoother at idle. I think the intake centerline of 106 is what's thrown me a little curveball, not so much the change in firing order.

HYDRAULIC ROLLER 4/7 SWAP CAMSHAFT AND LIFTER KIT; 1967 - 1990 OLDSMOBILE 260-455 1800 TO 5600 HOWARDS CAMS CL514825-10

At first listen, yes, you would think the lobe separation angle (LSA) is tighter at 107-108... Of course as Vortech has stated, the flywheel effect (heavier rotating mass of either a torque converter or a flywheel and pressure plate) once installed into the vehicle will help smooth the idle out a tad, but it's not going to change that thunderous cackle which will definitely turn some heads when I hit the button on the electric exhaust cutouts in the 442

Thumpety thumpety thumpety thumpety thumpety thumpety music to my ears. I ran 5 gallons of gas through it just letting it cackle away on the stand while working on other things in the shop just to listen to that wonderful cackle in the background. Curious to see what it will sound like running through ported Thornton W30 reproduction manifolds along with the X pipe exhaust system once in the car, as all of the cylinders get "commonized" in the exhaust crossover unlike an old school fully split dual exhaust system.

Paul...

 

By way of comparison, here is the 403 build with the Crane roller in it, running the good ol' 1-8-4-3-6-5-7-2 firing order:



Small little roller, but runs like the wind well into 6500 RPM - fantastic low end torque too.

Same headers and mufflers as are on the 455 build with the Howards 4-7 swap roller. Of course it sounds completely different in the car now with the Thornton W31 manifolds and the Pypes X pipe 2 1/2" to the tail full exhaust system. I have had people actually pull me over wanting to know what was in the car making such sweet music - it does sound VERY exotic, like nothing I've ever heard before. I'll have to shoot some video next time I have the car out.

 

That's just a 4/7 swap not an LS firing order. The LS order is 1-8-7-2-6-5-4-3.

 

The early "Rockets" (1949 thru 1964) had a 18736542 firing order.
Not sure why Olds changed to 18436572 when they re-designed the engine.
I don't see why switching firing orders would add any power to the engine.
Can someone explain this?

 

X2 Charlie

 

Chevy Small Block Firing Orders: The Evolution of Cylinder Firing Order Swaps (onallcylinders.com)

 

YOU ARE CORRECT. I don't know where in the world I got the idea that the 4/7 swap brought on the late model LS firing. Somewhere along the line that got into my head, thinking it may have been when I called Howards to discuss the cam. I seem to recall them telling me this grind was the LS firing order, OR I had a wire crossed in what was said versus what I thought I heard. Maybe it was two cylinders closer to the LS firing order, or I was off my meds that day (lol?) I want to make sure that any information I ever put out there is accurate - good thing there is a safety net here! I wish I could go back and edit the title line of previous posts, but I can at least straighten out the mistaken information in the message main body.

THANK YOU FOR BRINGING THIS TO MY ATTENTION, and especially for anybody else reading. This was an "oops" of mistaken information, and I now stand corrected.

Paul...

 

Has anybody to your knowledge tried a true LS firing order in a Gen II Olds yet? I'm thinking hell, I'll give it a whirl win / lose / or draw. Engines don't know what names are on their valve covers, only bore x stroke x compression x valve area. I have yet another 455, Speedmaster heads, ICON IC886 pistons, 10:1 compression ratio test mule engine here that I can swap in an LS firing order cam, evaluate it on the stand, then run it in the car - I believe it should behave fine (or better). Take a popular modern milder / civilized grind, move the lobes around to swap cylinders 2 and 3 in addition to 4 / 7 and voila! If I like it, I'll get another one cut for the Twin TorqStorm 540 I'm building.

Mark, did I understand correctly that you are cutting cams or have a connect for this? I'm intrigued to put the revised 1-8-7-2-6-5-4-3 to the test in one of my cam thrust plate prototyping engines (hydraulic roller).

Paul...

 

I have an LS firing order cam in my 529 Olds. Be prepared to have a custom cam core made if you choose to go that route.

 

x2.

 

Is there any kind of measurement going to happen, or are you just happy with having something different? If 4/7 swap cams are so great, everyone would have them. People still use flat tappets, too so, there's that....

 

Let's face it - the Gen II Olds V8 is dated, starting in '64, then dying off in the last wheezer 307 for the 1990 model year, even using the archaic rope rear main seal to the very end. Everything I do to these engines these days is to use any modern advancement available on my builds within reason. Updating the silly rope rear main seal, moving from points to electronic ignitions of various natures, MLS head gaskets, aluminum heads, modern ring packs, roller cams, EFI and so on...

I was excited about the 4-7 swap cam as its advantages are listed as : ---Hot spots solution with the 4&7 swap --- 5/7 hot spot problem moved to the front 4/2 which is a cooler spot. ---Bearing issues with 4&7 and 2&3 swap --- better bearing life moving the pairs that fire on the same pin to the back of the engine so the drivetrain can better handle the dampening of the forces...

So what would be the next advancement? Naturally doing the 4/7 swap one better, moving to the true LS firing order. I love how Chevy has stayed with the conventional pushrod V8, but has scienced it out so much over the years that I consider it superior to the Ford and Mopar modern V8's - same small packaging / general architecture as the venerable ol' SBC, but very advanced in many ways. I see all of these guys stuffing LS engines into their cars, which is great, but I'd prefer to keep an Olds engine in my 442, just a vastly advanced 21st century version.

Cutting a custom grind for one of my cam thrust plate test engines will give me the opportunity to run it on a stand, then in the car, where I can evaluate it with my butt dyno and the Gtech Pro. If I get the urge, I can then put it on a rear wheel dyno. The 4/7 swap 11:1 455 will be in the car before this next 10:1 455 test engine goes in. If I can get the LS firing order cam swapped in, it will make for a decent back to back comparison, as both engines will be very similar with exception to being a point of compression apart from each other. Most all else will be the same. From what I have researched, the advantages of the LS firing order are: Promotes better harmonics, Boosts power, Enhanced torque, Better cooling, Allows for the general smooth running of the engine.

If I like the LS firing order cam, which I may have already talked myself into based upon the above listed merits, it will go into the twin TorqStorm Supercharged Rocket block based 540 build that is currently in the works. I have the 403, two 455's, a 488 stroker, and the 540 build. I am selling off 3 of the engines, keeping one of them I deem as a best back up in case the 540 goes down. The 540 will be running a set of Speedmaster heads heavily CNC massaged by Mark (cutlassEFI), along with some Wiseco hard anodized pistons, coil on plug ignition, MPFI with twin drive by wire 105mm throttle bodies, 220 lb / hr injectors, Scat full counterweighted CNC billet crank... set up for flex fuel - I think it will like the E85 on boost. So all of the test mule engines are in existence to prove out the cam thrust plate designs I have developed, and also being generally moved out of my inventory to help make way for the 540 to be built just right. If I could put direct cylinder injection into the 540, that would be really cool. That's not a realistic upgrade to pursue though. The LS firing order cam? Heck ya man - have it ground, slide it in, then enjoy the benefits it brings to the table.

Chadman - can you tell me who produced your LS firing order cam? I'm sure they have saved the file, but could detune the cam WAY down to suit my needs. I understand that you are implying $$$. I can make a decision if I want to have one cut for a test mule 455 AND another for the 540. If it's beyond the threshold of what makes sense to just slide into one of the 455's to evaluate, then I am certain that I will still want to do this to the 540.

Paul...

 

Bullet has made me a few cams with custom cores as well as this current LS firing order cam.

 

Bullet always seems to find Round lobe roller cores .

flat tappet cores as well if you need a really narrow lsa

 

I called Bullet today and spoke with Mark in great length about a custom Olds hydraulic roller grind with the LS firing order. This guy REALLY knows his stuff - 35 years in the business, so I listened VERY carefully. It took me a few to get him really engaged, debating a "simple" 4/7 swap versus the full LS firing order initially. He was resisting at first, but seemed to warm up to the reasoning behind my end of the discussion not too far into the conversation, where we then started basically rough drafting LSA, duration, lift and so on. I must have caught him at just the right time, as he spent 45 minutes with me on the phone - almost unheard of these days! You get two engineers together and start brain storming and look out lol.

He asked me to give him 24 hours of soak time to mentalize it, then call him back to take it further. I am doing one reasonably mellow initial test LS firing order billet roller (in one of my 455 cam thrust plate prototyping engines), then going for the gusto not too much longer after that for the twin TorqStorm supercharged Rocket Racing block based 540 build. $800 plus a 4 month lead time. After researching various different quality roller cams over the last year, that price is not out of bound at all, only about $200 more than a standard production off the shelf quality roller. Actually an excellent price considering the custom cam core and design work.

Soooooo..... I believe it's almost in motion now, hoping tomorrow afternoon's conversation with Mark at Bullet / Ultradyne locks it in and gets it into production. I have so much on my plate right now that I will back burner that 455 until the cam nears completion. It seems like the older I get, the faster time flies, so 120 days lead time didn't phase me one bit. Before I know it, I will be holding that custom cam in my hands, ready to slide it into the engine, lashing the valves, and firing it up! I wish I had a true comparison to work with - another absolutely identical build with only the 4/7 swap versus this one with the LS firing order. That way I could really do an apples to apples comparison, but the other engine with the 4/7 swap cam in it has one more point of compression, and Howards Cams design spin on the lobe patterns...

I will keep you posted - I'm excited to give this a go!

Paul... (the Ukranian mad scientist lol)

 

This is all I could get out of Chad about the LS firing order on his 529. Would you care to expound upon this? I assume it has to do with the loading on the crank.....?

 

Crank harmonics as well as camshaft harmonics increase bearing life and valve train stability. Its also helps cooling by moving adjacent firing cylinders to the outside corners of the block.
I could see this helping high rpm engines and endurance engines like jet boats. As far as low rpm street engines gains might be harder to find.
I do think the topic matter is cool thanks for posting.
On a side note this takes me back to a shop instructor that had us memories 18436572

 

X2 of good topic. Nice to see some technical stuff like this.

 

Even at 12 years old, you could wake me at any hour and I could recite this firing order LOL. Back in the days of working as an ASE Advanced Engine Performance Master Tech, it was interesting to see how many other non GM engines also used this firing order. If you even took some Ford engines and renamed the cylinders "GM / Mopar style", meaning odd bank and even bank (instead of their 1234, 5678 system), you would find this venerable firing order in play on certain engines.

I have also received a tip that this outfit, essentially in my backyard of where I used to live in Detroit, also specializes in one off billet cams, VERY familiar with the "C" LS firing order:

LSM Engineering

Besides already in discussions with Bullet Cams, I will be swinging this past LSM also to see what they can do too.

I am determined to make this happen - no stopping me now. The engineer in me has become way to obsessed with this now = locked in. To make for a much closer comparison, I have taken the 10:1 test mule engine this cam is going into and refitting it with pistons to make for 11:1 compression. That way I will be able to do a much closer comparison between the 4/7 swap with the Howards cam, and this next engine with the LS firing order cam (without the compression variable of 10:1 to versus 11:1). EVERYTHING is going to be identical between the two engines now. I am however possibly going to change the specs on the cam a little - looking at 111-112 LSA as opposed to 110, slightly milder .050 duration, BUT offset with a higher lift, but again, that may skew the comparison between the two engines so still on the fence on this. Short of getting the blank and shipping it into Howards to have them machine it, there is still going to be a variable even if the custom "C" firing order cam is technically spec on spec, as raw specs don't exactly tell the whole story of proprietary little things each cam company does with their lobe profiles (ramp up profiles versus ramp down, dwell at wide open..). The other way to do this is to yank the Howards cam and send it in to have the lobes profiled and exactly matched on the revised firing order custom cam... BUT, that's really not what I'm trying to do here. I am looking to experiment with every possible modernization I can do to our ol' beloved Gen II Olds V8's. They went extinct in 1990, but Rocket Racing has brought them back with quite a few cool internal modernizations!

Again, this is all working towards this end goal:



DMR Spec Twin TorqStorm Blow Through

DMR Blow Through 2

TorqStorm Web Image

I am going to be running sequential MPFI, twin 105mm drive by wire throttle bodies, coil on plug ignition, methanol injection, Flex Fuel, and now of course the LS series firing order cam through a highly modified Offy 360 low rise dual quad manifold:


Offy 360 Low Rise that will be getting fuel injector bungs TIG welded in, lots of airflow surgery / optimization

One super charger feeding into each throttle body. I should be able to build a few ponies without having to plumb the fire out of it to intercool it. There is only so much my lil' '86 442 can handle, even with the UMI frame notch kit and all of the various bracing already installed. Looks like 295's are going to be where I draw the line. Yeah, it would be cool to back half the car to take full potential of the power, but this is a 69,000 mile original immaculate car that I am trying not to cut anymore than needed. I have saved EVERYTHING - the original numbers matching drivetrain, all that stuff just in case somebody may want to restore it back to stock long after I'm gone (though I just can't picture that lol - restoring it back to its original 180 horse self - NOT!). The goal with this build is to modernize it into the 21st century, overpower it to the point that I can detune it to run smooth enough for my wife and daughter to drive (IN VALET MODE ALTERNATE TUNE OF COURSE !!!), and be stone reliable to run the HotRod Power Tour and such.

Anyway, I see I'm rambling on, so I better sign off and get back to work!

Paul...

 

From what I’ve read the reasons GM switched firing order in the LS was #1 to improve reluctor wheel accuracy , because it’s at the rear crank journal area where its absorbing all firing pulses , and #2 to reduce crank bearing loads in one area.

I’ve yet to find any high end pro builder say they gained power with a 4/7 or LS swap. Daren Morgan did extensive testing years ago and did find a miniscule bump in pro stock engines with the 4/7, but couldn’t explain why.

in the Olds, especially BB, the swaps could help reduce #4 main bearing loads, which is where it has issues sometimes with stock cranks moving around

 

How many people have run those twin charger setups hard for a few seasons? Was there accelerated wear on the #1 crank journal? Really, I can only see downsides to the twin setup...extra tension on the crank snout, elevated harmonics from the very long belts, belt slippage, extra weight and all that garbage hanging off the front of the engine. Don't get me wrong, I'm not against boosting an engine, I just don't see the upside to the twins...My small block is getting a reverse rotation D1x with a short belt to keep all the above to a minimum. Just my opinion.

 

Interesting. I can see where reducing harmonics would extend longevity. It's crazy how a pro stock builder would be even remotely baffled by an unexplained power bump. Those guys chase every ounce of power they can!
I can also see a low buck, backyard build with an LS ECM, but that limits software choices sticking with junkyard stuff. HP Tuners is on a downslide with the EPA cracking down on open source tunes and standalone ECUs offering better user interfaces. I don't know if the juice is worth the squeeze, though. Besides, you'll lose the Olds exhaust note.

 

I think those set ups are more for the show than the go. Definitely not my thing.

 

Just got off the phone with Steve at LSM Engineering - both LS "C" firing order Olds custom roller cams $700 each, 90 +/- days! One for the 11:1 naturally aspirated, and the second one for the 540 Rocket block based twin TorqStorm build.

Now for the pundits, check out how much power this engine makes, and also how smoothly it idles:

 

Yeah, they max out around 7-9psi.

 

Ahh yes, the form over function crowd.

 

I believe you misinterpreted my post...

Never said they don't make power, that 1800hp is on 100% ethanol. For reference a single F2 would outperform the twins. What is the advantage of the twins over a properly sized single?

 

For sheer power, the single (street) charger typically does 750-1000 horse (without tickling it with nitrous). Twins can typically hit the 1500-1900 horse range. <-- That's just not where I'm heading with my build though. I don't want to cut up my core support to fit intercooler plumbing along with the intercooler into the nose of the vehicle. Heck, I've already got an oil cooler, trans cooler, and a power steering cooler neatly tucked up front as it is. The twins won't have to work hard at all to reach my boost goals of 12-15 PSI, which will keep the load on the drive belt way down, keep the supercharger noise levels down, keep the intake charge temps down, especially with the windshield washer fluid (no joke) being injected into the whistlers. Yeah, I could install a single charger and likely reach my objectives too, but everybody likes what they like, and I am very much looking forward to the symmetry of the twins from a visual perspective also. Same thing with modifying the Offenhauser low rise dual quad intake - I could put a 1000 cfm throttle body on a worked single plane intake to flow enough, but I want the symmetry of each charger feeding into its own throttle body for my own personal visual tastes... I am the artiste` and the vehicle is my canvas.

Now if I do eventually back half the car, all I need to do is intercool it, swap the cam out for a more aggressive one, change up the pulley speeds to double the boost levels, update the programming, fill it up with some race fuel and voila - easy 1800+ horse

Blame it on me being a Ukrainian if you have to lol

Paul...

 

The most important thing is to do what you want, its your car and that's the joy of it. Thanks for sharing what your doing. Besides, just by running an Olds we are all different from the crowd anyway.

 

I don't think anyone was criticized.I was just looking for some insight to see if there was any benefit to running twins over a properly sized single that I wasn't seeing...there isn't. Anyways, I digress and good luck to the OP.

 

I agree. Twice the plumbing nightmares with the twin setup. It will also make your alternator, power steering and AC hookups much more difficult. You are going to keep the AC right?

In any case the OP says he likes the look of the twin setup so I say go for it.

 

The twin DBW TBs scare me, but....

SEND IT!!!!