The motor in my Fathers 04 Suburban finally bit the dust, and was rolled into my shop, torn apart, and the motor stripped down. among other things, the cam journals and bearings are toasted.(amazingly enough the cam lobes look fine, almost brand new) The bearings were easy enough to find, but it appears that every single stock profile, 5.3L LS1, 3 bolt camshaft that isnt in an engine has been melted down into soda cans, as i cant find a single one anywhere. Theres several that i have found that have a profile Thats very close to stock, but nothing with the actual stock profile exists as far as i can find. i even had a friend that works at a GM dealership look, and GM says this camshaft has been discontinued since 2013. I know it sounds insane, but he has literally zero interest in any kind of performance cam whatsoever, and even less in dealing with a tune to make some other cam work. Im honestly a little lost as to where to go, ive been looking through forums but don't see a clear cut answer on what exactly the stock ECM in those trucks can or cant work with, as 99% of forums threads are "just get a tune". im hoping maybe on of you lovely GRM folks either have one in a box you be willing to part with or an idea on what the ECM is willing to tolerate as far as aftermarket cams. im trying to avoid having a custom one ground, as those are very much out of the budget.
Damn.... I used to have an LQ9 cam in a box somewhere, but I scrapped it because I figured it'd be easy to replace.
Driven5
UltraDork
8/24/20 10:47 p.m.
Step 1: Buy a complete 5.3 and a cheap performance cam
Step 2: Swap performance cam for stock cam, and stock cam into 'burban
Step 3: Profit
One of these would work equally well for much less money. These are for a single bolt cam gear I think, the Texas Speed cam might be your only option for a 3 bolt cam gear.
https://www.summitracing.com/parts/mel-mc1390/make/chevrolet
https://www.summitracing.com/parts/mel-mc1394/make/chevrolet
Driven5 said:
Step 1: Buy a complete 5.3 and a cheap performance cam
Step 2: Swap performance cam for stock cam, and stock cam into 'burban
Step 3: Profit
finding a 5.3 has been the hard part, they go for a premium here. the original plan was to buy a 5.3 and rebuild it ahead of time, and then swap in the rebuilt motor for the failing one, but it kicked the bucket before we could get one for a reasonable price.
Patientzero said:
Pricey but here you go.
https://www.texas-speed.com/p-4975-gm-1999-06-lm7-53-stock-camshaft.aspx
so far this is looking like my only option, Im just not sure if it will play nice with the factory tune/ECM or not, since its ever so slightly different.
Patientzero said:
One of these would work equally well for much less money. These are for a single bolt cam gear I think, the Texas Speed cam might be your only option for a 3 bolt cam gear.
https://www.summitracing.com/parts/mel-mc1390/make/chevrolet
https://www.summitracing.com/parts/mel-mc1394/make/chevrolet
yeah, ive seen those, im just not sure how much of a headache it would be to convert the truck to the single bolt cam. It may be worth it, as the single bolt cams seems to be plentiful in supply.
In reply to Gaunt596 :
It would be perfectly fine. It would take a much more significant change before it would need to be retuned.
Patientzero said:
In reply to Gaunt596 :
It would be perfectly fine. It would take a much more significant change before it would need to be retuned.
ah, good to know, also that camshaft is actually right on, I thought that was one of the close but no cigar ones i had come across.
You could probably do a stage 1 truck cam and not have to tune it.
I mean, if you have to buy a cam anyway.....
SkinnyG (Forum Supporter) said:
You could probably do a stage 1 truck cam and not have to tune it.
I mean, if you have to buy a cam anyway.....
yeah, thats the kicker though, as he wants nothing to do with a tuned truck, and i dont really wanna have to do the job twice cause the cam i picked didnt work. Ill talk to him tomorrow(make that today, whats sleep?) about the one from texas speed, since its dead on, just expensive, and im not sure where he is budget wise right this second
I think I have a stocker in the garage. I'll check later today.
I have an LM4 on the engine stand, slated for my Challenge build. I also have a hotter cam for it and the extra bits to install it IF I can stay under budget using them. I'll go through my anticipated spending and see if I'm comfortable enough to offer up the stock cam if Strike_Zero can't help.
Am I missing something- why not just hit rockauto up they have stock replacements? If you're looking at specs and something is a hair off because they split the difference between 2 sets of stock specs to sell the same replacement for both, nobody will feel the difference and neither will the computer. Honestly, I have an ls6 cam running on a stock 5.3 program right now and while it's definitely not optimized it runs well and doesn't throw codes.
The stock computer is amazingly flexible for camshafts.
Yes you can get better, but you can also get just about the same amount of better from tuning the stock setup. Not necessarily playing with timing or WOT mixture, just simply doing a fine tune of the MAF transfer table and the VE tables.
The MAF transfer table does 95% of the legwork in the stock setup, and is not affected by the camshaft. You only NEED to touch it if you change the stock airbox or ducting, that throws off how the MAF reads airflow. The fueling is done in direct proportion to airflow, and the ignition timing is based off of grams of air per cylinder per cycle, so timing will automatically optimize for greater or lesser airflow.
the VE table, as I gather, is mainly used for certain transients and for error checking the MAF. A cam change like you are looking at is not going to affect it in any way large enough to matter.
I have driven cars with wildly out of spec tunes (Summit catalog thrown at them, big cam, etc) and they drove well. Going with a cam size change that amounts to production tolerance, is not going to matter.
In reply to wae :
Either of those will work fine,
Pete. (l33t FS) said:
The stock computer is amazingly flexible for camshafts.
Yes you can get better, but you can also get just about the same amount of better from tuning the stock setup. Not necessarily playing with timing or WOT mixture, just simply doing a fine tune of the MAF transfer table and the VE tables.
The MAF transfer table does 95% of the legwork in the stock setup, and is not affected by the camshaft. You only NEED to touch it if you change the stock airbox or ducting, that throws off how the MAF reads airflow. The fueling is done in direct proportion to airflow, and the ignition timing is based off of grams of air per cylinder per cycle, so timing will automatically optimize for greater or lesser airflow.
the VE table, as I gather, is mainly used for certain transients and for error checking the MAF.
This is not accurate. Going to a cam much bigger than stock will cause startup and idle issues as well as screw up the VE table for part throttle driving. On the stock GM computer the map sensor(VE table) is used for part throttle and the MAF is used for high rpm and power enrichment. This threshold can be changed in the tune. Many "tuners" will set the threshold to zero and run MAF only because they don't know how to correct the VE table. It can also be set very high so the MAF is disabled. Many people do this when using boost. Both the VE table and MAF table need to be tuned separately. A bigger cam will also throw codes for knock and random misfire because the crank acceleration between firing events has changed.
Pete. (l33t FS) said:
Going with a cam size change that amounts to production tolerance, is not going to matter.
This is true.
I have an LS1 cam in a box if you are interested. I'm probably not going to use it. EDIT: I have a stock LS1 grind and a stock LR4.
Patrick (Forum Supporter) said:
Am I missing something- why not just hit rockauto up they have stock replacements? If you're looking at specs and something is a hair off because they split the difference between 2 sets of stock specs to sell the same replacement for both, nobody will feel the difference and neither will the computer. Honestly, I have an ls6 cam running on a stock 5.3 program right now and while it's definitely not optimized it runs well and doesn't throw codes.
That was actually the first place I checked, they have been out of stock on all of them for a couple months, but I see they got some in now. Although since I see some of you have one sitting I'd rather see my money go to of yall instead.
Daylan C (Forum Supporter) said:
I have an LS1 cam in a box if you are interested. I'm probably not going to use it. EDIT: I have a stock LS1 grind and a stock LR4.
I'm definitely interested in the ls1 cam. Send me a message if you dont mind, I'm not exactly sure how the PMS work here.
I'd also just like to say I appreciate the help and parts offers. Sometimes i think I get stuck too far in my own head and need some outside help to get me straight again.
Gaunt596 said:
Daylan C (Forum Supporter) said:
I have an LS1 cam in a box if you are interested. I'm probably not going to use it. EDIT: I have a stock LS1 grind and a stock LR4.
I'm definitely interested in the ls1 cam. Send me a message if you dont mind, I'm not exactly sure how the PMS work here.
Just to be clear. A LS1 and a 5.3 truck motor are not the same thing. A LS1 cam is going to be more different than any of the 5.3 cams listed in this thread. That may not play nice with your stock tune.
