Good Morning All,

I'm currently doing an LSX swap with a 5.3 and I am looking for some thoughts and suggestions on a cam. I will have Stock 5.3 heads for now and and LS1 Intake.

I contacted Comp Cams and the cam they suggested based on what I had and wanted was:

222/224 @.050 566/568 112lsa

However I stumbled on a pretty good deal on the Cam described below and the specs are similar. I have read a lot into cam specs over the last little while but I would really like a second, third, and so on opinion before I commit.

222/226 @.050 596/598 113 + 2 lsa

Another one of my concerns is whether or not the stock 5.3 heads will handle that much lift. From the reading it seems like the heads will handle 0.600 lift with the proper springs which I will be of course getting. But I was wondering if someone could confirm that.

Also, I have not been able to find the rocker arm ratio of the stock rockers on a 5.3 and I was wondering if someone might know because the cam listed is for 1.7 ratio rockers and if my rockers are less I will have less issues with lift.

Thanks for the help all,

 

I just found the rocker arm ratio. It's 1.7:1

 

Get the second one. Should be fine with PAC1518 springs. Check ptv and mill to 0.100" clearance and it'll be a hella fun little combo with some good flowing exhaust and intake

 

+1 To that advice above.Some good springs and go with cam#2.The first cam isnt bad but it will leave you wanting more in the end.

 

The first cam is great too though, thats a very common grind and I ran it myself for a while but the second cam looks to have the newer lobe designs id guess which are softer off the seat and run quieter, smoother, and make more jam. IIRC the first cam is still an XE lobe which is a sbc carry over. Makes good power but is less than ideal as the base circle of LS cams is larger so the old lobe ground onto these larger cams makes them hit pretty hard on initial lift and return so they chatter bad and dont rev as high without risk.... The increased lift is a by product of the lobe itself so its a smooth roll around all together.

Its something like that anyways, my heads going to explode one day trying to retain all this

 

I am getting Comp 918s with the deal and from what I understand those are more then good enough for 0.600 lift.

Well it looks like I am sold on option 2.

I will have to check PTV clearance but I think I should be good to go.

Thanks for the input guys

 

Im not a fan of used valve springs AT ALL i have experience and its not good... If they are silver in color? They're garbage throw em out.

Check this;

http://www.performancetrucks.net/for...prings-492511/

They even had a recall going on them iirc. For the 160 bones for new springs? Well worth it man. Hope it helps you negotiate a better deal with this info

 

Thanks for the heads up cam... I contacted the guy and I'm just taking the cam and I'll get good springs. Didn't realize the Comp ones were so bad...

What would you suggest for springs? I think PAC1518 was mentioned above

 

I can get u a set of dual springs for 215.00 shipped.... give you some form of security if a few thousand miles down the road one of those single springs were to break... and I'd go with the second cam....

 

Springs are a funny thing. Finding "the spring" to use changes a lot as suppliers change up methods. Patriot Golds have changed up suppliers too. Not saying their new duals are not great but they are just not the same so...

I wouldn't run duals on those small cams. You'll likely end up damaging the valves... again I learned this the hard way. The beehives work very well and the nitrided ones are rated to last a good long time just be sure to change em up after 30k miles or so

 

I havent had any personal experience with PAC springs, but i just stumbled on this thread today randomly.

http://ls1tech.com/forums/lt1-lt4-mo...kes-again.html

its not the same PAC model # Cam is refering too

 

Interesting BUT... the 1218 is the non nitrided spring PAC sells and they are brown.... The 1518 is nitrided which gives them a more golden look with a slight colorful hue.

If I only saw that broke spring and someone asked me what it was? Looks a lot like a comp 918 to me.

That said with springs year to year choosing "the spring" changes. You have to stay on top of whos making what, how they make it, and who they supply/buy from.

PAC used to make the original 918's for comp for instance. The ones that broke... but GM made some poo engines too ( rear drive 60 deg v6? barf ) but you get the idea me thinks


If you want to get the good stuff? Look up Brian Tooley and tell him cam sent ya

 

I should also note too that PAC had a bad batch and recalled a bunch recently.

The saying goes if you aint breakin? You aint racin

 

Do you mean send him a message via the "Contact Us" part of his website?

 

Id say thats a good start Hes on tech as well you can PM him there too if need be. I may in fact be using one of his cams soon as well

 

the "new" comp 918's are better springs. i've been running them in my combo for over 2k hard miles. the shop that i purchased them through, uses them on a lot of their builds and they haven't had any problems since comp addressed the issues. don't be afraid of them, they are great spings, and will give you more miles than a dual spring setup.

 

Yes indeed the "new" 918's look to be back to the good stuff

 

Im using the pac 1518 springs with no issues and when I was shopping around most guys I know and from neighboring shops have said the same.Never bother with used springs since they are cheap to get new,the old 918 comp springs gave alot of headaches for shops but the newer versions have been ok so far and you can have too much spring which can be as bad as using stock springs on a medium cam.

What else are you doing for your swap? 6sp/auto...exhaust?

 

i used comp 918 springs. stock 5.3 heads and internals. except cam.
224-226-588-592-114+4 cam in it. it was a decent cam. idled great. pita to tune at low rpm,s. but it was wonderful on nos and my 175 shot. the 224 cam listed first has been used many many times in a 5.3 with great results.

 

I plan on running this one as CAM- suggested http://www.engpwrsys.com/index.php?a...od&productId=5

I cant for my life find an idle video on it.

 

Sorry for delayed response.

I'm not doing anything too crazy right now. Because of the relatively high cost of doing an LSX swap (compared to swapping in a bigger SBC) I am just doing a moderate 5.3 build. Cam, tune and LS1 intake is really all I am doing with the engine for now. My intent is to swap in a decent engine for now and them finish the rest of the car up like a 12bolt so it can handle some real power.

I am doing brand new exhaust from the heads to the tail pipe and I am rebuilding a 4l60E for now. When I stay auto forever I am not sure but for now, I have it and it is basically a direct swap from the 700R4 I have now. Also it makes it a lot better for other pansies to drive it later because people's ability to drive is fading these days.

Anyways, thats the novel version of my swap and intent and the short version is I am a bit of a timeline to have it done before next summer so I am making some comprimises.

 

Crazy times but that is so true....

Sounds like a very sensible and doable build plan to me. Have fun with it

 

Yeah thats a cherry little street/strip cam. EPS lobes are mint. There will be a little chop to that one.... not a ton but it'll be there

 

How did you do that? Ive never heard of that or seen it. I've always run dual golds. From. 563 lift to .621.

 

With the low lift smaller cams especially the rocker tip movement is minimized and concentrated on a smaller area of the valve stem and it wears them down if you run big springs. My first LS1 i ran a tr224 and patriot golds and this happened to me. I thought it was a bad batch of valves until I bumped into Brian Tooley commenting on this issue.

Theres ALWAYS something to improve on, remember that. I dont know jack **** really... constantly learning

 

That makes sense. I more than trust Brian. Thanks for the info, even though ill probably never run a cam under. 600 lift again lol. Well maybe off I go Turbo.

 

Yeah fak... turbos.... Learning now. Painnnnnnn lol

As for under 600 lift? Hell yeah throw them old sbc lobes back in time where they belong :P

 

If I go Turbo I may use a 224/228 115 cam or so. Depending on what lobes I get it cut on, it may be under. 600.

I might just keep it simple, do a stroked 402 and spray it for when I need more power. Every Turbo car I know breaks and I like to drive my car more than 5k per summer.


Op, if you can call futral or EPS and get a custom cam spec'd. Comp sucks. They recommend that damn 224 to everyone with an ls build.it seems. Myself included.

 

Im with ya. I dont mind breaking this next one.... First engine for boost is just a trial anyways right? Just like picking stalls its mighty rare to hit it square the first time, you have to play with them to get it "right" but im just having fun with my Dad so not overly concerned about it getting beat on too bad, just now and then when i need to go fast....er.

A lot of the failures with boost are meth junkie motors. Put the good gas in em and they'll hold together a while. Its getting to that 90% level with all the parts thats so hard. Soon as you go over on one? You rob percentages from another. Just the way life goes its funny how it all relates. Anyways i got a build thread going on the Planet if your interested in what im up to....

 

That is interesting and first time i ever heard of that. I would have thought bad valves because the stem material shouldnt wear if geometry is correct and it isnt floating valves. You are suppose to have mimimal area for contact pattern and sweep. I just know alot of local guys running various dual springs on various cams and never heard of this issue. For some of the less aggressive lobes running too much pressure from a stiff dual is overkill but not sure there is any damage risk in doing that. Some guys say there is but certainly cant be more damaging to the engine compared to too little spring pressure for the application. Thats why there are many duals of various pressure and load rates for various cam lobe applications.
Just doesnt seem to make sense to me, but i aint in the know when it comes to valvetrain dynamics compared to experts who do it for a living lol. I just know guys who run solid rollers dont seem to have valve stem wear with huge 800-1000 lb triple spring loads when geometry is right. We are just looking at girly hyd roller loads

 

Yeah I had pretty much the same reaction. I come from the land of MORE SPRING!!!! lol its never enough hahaa

But theres always learning to be done. Chasing parts man it never ends....

Regarding the springs though.... I have to admit as skeptical as I was about them, these beehives im running in my last build work amazing. I spun to 7500 on the regular and they didnt miss a beat. Stock L92 valves and stock steel retainers too

Also keep in mind on these things they get driven, a LOT. I put years of daily driving miles on those valves and until I took the heads off for a swap I was unaware of any damage, it was slight but definitely would have eventually caused grief. As for the big donkey cam race cars? They usually dont go more than a few hundred miles in their entire life, its just WIDE open miles

 

True some of the race guys dont get mileage as much but i thought some local guys here had run some hard street miles. I will have to ask around. I was gonna do a cam on my summer daily driver but now gonna turbo it. Wasnt an oiling problem or anything like that? Wonder if guys have had that problem on aftermarket valves?

Do you know what an L92 valve weighs and what cam you used on that setup? My sbc had a float problem with 180 lbs seat 450 open springs with a 2.100" valve in my sbc heads. I dont think a beehive would control my cam and cam grinder believes springs are adequate but just investigating possibilities. My sbc hyd roller makes some ls cams look weak. .640" on a 1.6 rocker, not that 1.7 stuff haha

 

Dangit! Theres a great thread over at tech with a side by side comparo of L92 and LS3 valves and their respective weights but.... the pics are gone. I have valves here I'll weight for ya when i get a chance.

As for my cam? Its an EPS custom grind. 220/230 600 114 give or take a point or three on the dur I cant recall right now.

Im not a fan of increasing rocker leverage either... Speeds up valve movement too much making things all that much harder to control. You ever see Rehr Morrisons strobe light tester for valve springs? Fukn cool gadget lemme tell ya

 

Nope havent seen that but sounds cool. Seen some high speed vid of valve motion and its crazy

 

Rehr's theory was that the majority of engine failures were top end related and not bottom ends even when the damage was isolated down below. He had some funky theories and im sure most people looked at them a bit strangely whilst looking at valvesprings while everyone else was simply building king kong crank shafts and jumbo connecting rids im sure you've all seen them.

They took this line of thinking so far that he made a frequency referenced strobe light to fire in sequence with a spinotron. So he could literally "freeze" the valve in static position at extreme RPM to see what was actually going on. ( Smokey Yunick farmer style ) and what they saw shook things up quite a bit because they realized then that the valves were actually bouncing at least three times before settling down upon return lift. So the quest was on to stabilize everything up top which we still work on, but it sure did stop a lot of engine failures as a result. Im not sure of the stats but I do know Rehr Morrisons shop built some of the winningest most durable BBC engines then, and likely now although I really cant say i was doing research at the time I found their research and on it goes. I dont know them personally but I sure do admire their work.


So now we got these funky beehives that stack over themselves to remove odd harmonics and share stress load and all sorts of technogadgety stuff. Only downside is the QC on building them? Cannot have any holes.... One spring? One chance. Thats the downside