Cam Upgrade
 

I want to put a cam in my engine, and put together the parts list below.
Parts:
ST5 Camshaft: 325$
136 LB Valve Springs: 140$
Valve Spring Retainers: 45$
Pushrods 100$
Roller Lifters: 100$
Cam Install Kit: 130$
Oil Pump Kit: 70$
Double Chain Timing Set: 135$
Valve Seals: 19$
Valve Locks: 26$
Cam Bearings: 22$
1.65 Rocker Arms: 250$
At Home Install:
: 260$
: 72$
Camshaft Degreeing Kit: 100$
: 100$
Install Lube x2: 20$
Break In Oil x5: 35$
Tune:
ZZP 1.0 PCM Update: 40$

I wanted to get feedback on the "compatibility", so to speak. My main concerns are too much lift, resulting in a valve touching a piston, and the pushrod length. I'm not quite sure about what they should be. Possibly 6.95. Also, is there any machining needed to run 3/8" pushrods, as apposed to the stock 5/16"?

IMO, not a huge fan. For whatever reason, it seems like the ST4 cars make just as much or even more power than the ST5 cars. The ST5 is bigger (and thus has worse drivability and is harder to tune) for no benefit that I can see.



Not sure if they machine the gear, the website doesnt seem to mention that they do. Just keep in mind that the crank sprocket doesnt properly fit the US 3800 snout and will need to be chamfered to properly fit or you'll tear chains up as the crank gear wont go on all the way.



I wouldn't waste the time. Unless the engine has a bazillion miles. I've never seen a spun cam bearing in a 3800. The risk from a botched install is worse than the risk of a stock one spinning IMO.



Defintiely would skip this. If the ST5 isnt big enough for you, get a custom ground cam with the lift you actually want, especially if you're dumping this kind of money in it. This cam is plenty big on stock 1.6s.

Only rocker swap I'd consider would be to a nice roller tip, like a T&D or something, but I wouldn't waste money on higher lift rockers when you're already pulling the cam.




ICK, definitely not. If you're dumping this kind of money into the car, you're way beyond mail order tunes. Buy a tuner and learn to tune, find a local shop to do it, or get one of the big 3800 shops to do it. 1.0 mall order tunes are fine for basic bolt on setups, but clearly you're aiming for an all out build here given your cam choice.

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I wanted to get feedback on the "compatibility", so to speak. My main concerns are too much lift, resulting in a valve touching a piston, and the pushrod length. I'm not quite sure about what they should be. Possibly 6.95. Also, is there any machining needed to run 3/8" pushrods, as apposed to the stock 5/16"?

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For both questions, you need to check that yourself. Buy a pushrod length checker to find exactly what it needs. It's literally $12 from zzp and you can sell it when you're done.

For PV clearance, get some clay, put everything together and measure it. No one can say for sure it wont hit, there are a bunch of manufacturing tolerance stack ups involved and depending on how much you advance or retard the cam can make the setup hit or not. The cost is only a few bucks for clay and your time.

I dont think it's super likely if you just run the cam alone w/o rockers. The lift is fairly far below the biggest cams people have run in 3800s, but again, the grind profile / sprocket timing can create issues. What's worse is that its possible to have just enough clearance at idle, but end up with contact at high rpm. As the result is catastrophic, it's worth a few bucks and an hour to get the actual measurement for your setup.

I had no issues running the 3/8"s. May have to trim the HG a touch depending which you run, but I didn't have to. You're only talking about 1/32" all around which very tiny.


A few other related things I didn't see mentioned:
-Ported heads. Doesnt make sense to run a giant cam on stock heads.
-Converter. A big cam really needs a higher stall to work well. Low speed drivability gets worse, and the powerband is shifted further up, so you really want a converter that matches your setup / what you're trying to do.
-GMR trans parts - primarily the chain, but the input shaft would be nice too. The current top of the line chains wont hold up to an all out turbo build (which I assume is the intent given the choice of one of the biggest 3800 turbo cams out there), and since the GMR stuff isnt made anymore, there's not much point in building a crazy powerplant if you cant even use it without tearing up transmissions.

The only reason I went with the ST5 over the 2 or 4 was the lope at idle. I'll definitely take your opinion into consideration.

I did read about that somewhere. Does that need to be done by a machine shop, or can it be done by myself?

As far as I know, the engine I'm running now has 232K miles on it. Would that warrant bearings, or still not worth the time?

The reason I included these in the parts list was the weight savings over the stock rockers, and peace of mind in new parts, rather than 232K mile stock parts.

Would it be safe to drive to a shop after install with the current tune? What about a break in period before dyno pulls?

As far as I've heard from others on this forum, the GMR 1" chain is getting rare, and quite expensive.

Certainly lots of opinions on this, but I think it's crazy to pick a cam for the sound. That's literally the brain of the engine and should be matched to the rest of the build and the plans of use for the vehicle. The sound it makes is just a byproduct.

Offical answer is of course going to be machine shop. Personal opinion though - the fix isnt rocket science and could certainly be replicated by a good home mechanic with the right tools. Of course no shop will tell you that since they're afraid of some random dude going to town with an angle grinder or something.


I may have mentioned it before in another thread, but that warrants just finding another bottom end IMO. That's higher than 95%+ of what you're going to find in a junkyard or for sale online.

If for whatever reason, you're set on keeping that block, I'd agree it needs new cam bearings (and all the other bearings, and all of the refreshed machine shop work to go along with it), but you'll probably have at least $2k++ in it and could've got at least 2 reasonable mileage bottom ends for that money.


I wouldn't worry about the tiny weight savings, an all out turbo build will already make way more power than you're going to want. As with the rest of the bottom end, there are plenty of far lower mileage stock rockers out there that you could just buy and bolt on. You could probably even ge a set nearly free from the forums from someone who has upgraded. I've still got my set of 60k stock rockers just in case I had a failure with my aftermarket rollers.


Given all the upgrade rockers sold across all the vendors, I'm sure you can find some fairly local. Stock rockers are extremely robust - they dont have to be 0 mile, even 50 or 100k would be fine.

There are only a handful of engine mods that'll cause problems driving to a dyno without a tune:
-Different fuel injectors (you can swap these in the parking lot in 15 mins though)
-Different MAF/MAP
-Drasticslly different TB size

Obviously you just take it easy and stay completely out of boost. If you're worried though, you can always just flat bed it there.

In terms of break in, there is no break in required for modern roller cams. Just swap the cam in and let it rip.

Totally correct, but I don't see what the alternative is. This has the potential to be a 500-600+ whp setup if everything else is right (again assuming an all out build based on a giant cam turbo setup). The best shelf stock chain right now, the 7/8"s is good for maybe mid 400s at best, depending on use.

One option is to drop the $4200 on that built trans with the 7/8" and hope it doesnt blow up day 1 on the dyno and flush all that money down the toilet. If it does make it through, you'll always be afraid to really get into it as you'll know you one day its going to puke parts everywhere and you'll be out another $5k for another go at it.

The other (better IMO) option is to start actively sourcing the parts you're going to need to be able to actually support this power level. That's the unfortunate reality of modding this platform to high levels today. Just seems to make more sense to me to buy the hardest to find parts first so you're not desperate when you've got everything else together and are just waiting on trans parts to drop it in. All of the stuff you listed above could be sitting on your front door step tomorrow morning if you needed it, the key trans parts - not so much.

Sure, power goals and the use definitely play a huge roal in parts decisions, but I think the sound, and enjoyment should be thought of as well.

How much do you think it would cost to have that done?


IMO, I'd rather spend the extra money on better quality, brand new parts.

Yeah, it would be smart to do that, but I don't have the funds at the moment. And I'm starting to run out of sub 500$ projects on the car. Guess it's time to start saving up for the big stuff.

Honest question - have you ever owned a car with a big cam? There are lots of drawbacks to doing so just so 'it sounds cool'. Street enjoyment is generally worse with a big cam, and cost goes up a lot. Handful of examples :
-Increased valvetrain wear. Big cams will wear out components faster as you're increasing acceleration of the valve. Springs will become a maintenance item as will timing chains.
-Drivability is worse on the street. Low speed driving manners are notably worse. Power band is shifted higher in the rpm range, out of the area you'll be using it on the street 99% of the time.
-Increased costs. A big cam needs a properly matched converter, ported heads that work with the cam, heavy springs, stronger chain, etc etc. The cost of all that is well beyond a smaller cam that may be as cheap as just the cam and some springs.

With that said, I've never owned a ST5, I've got a IS3 BC. Just throwing out there a few of the many downsides to running a big cam.

Another option if sound is the only reason you're doing a cam - you can get a custom ground cam with that in mind. They can make a cam that's easier on parts and doesnt need super stiff springs and a double roller by mostly just playing with duration and LSA. Sure it wont make the power of a big race cam, but at least itll get you closer to stock reliability.

No clue, I had mine done more than a decade ago. If it is still needed on the new sets (itll be obvious when you go to install it), it's just a simple machining step. Cant imagine it being much more than a hundred bucks or so

Better quality than OEM? Lol. Try not to fall into the trap of thinking anything aftermarket is automatically better. It's usually the other way around - aftermarket companies have far less to spend on engineering and generally have far worse quality control processes than OEM. In general, failure rates of aftermarket stuff tends to be much higher.

If you're dead set on spending money on something you dont need, at least get some nice roller tip rockers while you're at it.

Just dont want you to get stuck at the end getting desperate for them. Prices will go up and they will get more rare as time goes on and people destroy or wear out the existing sets.

TBH If you factor in the total cost of everything needed to run a big cam (your list above + a converter + heads), you're at least in the rough ballpark of being able to buy a chain set.

If the cost of the GMR parts is a concern, I'd reccomend even more strongly against dumping tons of cash into a full on engine rebuild. On the 3800, the trans needs the most attention, not the engine. Plenty of people have proven this at 600+ whp on a SBE.

No, I haven't, nor have I even ridden in one. My 2000 Monte is my first and only vehicle.
I am aware that with a cam of this size, and valves of this strength that more items become wear items. Can you give an example(s) of how the street driveability is worse?

Sound isn't the only reason I'm looking into getting a cam. I want to eventually make the 500-600+ whp you said was possible. The sound is just another aspect.

The main thing I was referring to with better than OEM quality was the Clevite bearings.

You mentioned T&D roller rockers. I went to their website but couldn't easily find ones for the 3800. Do you have a link, or part number?


Yeah, I do know that it'll require extensive attention unfortunately.

Wow, had no idea. Makes 2 things come to mind:
-First is that I'd scrap going with some kind of crazy build and just start with turbo kit on a stock 3800. That'll be more than enough to be fun as itll be more than double your current power and will still be relatively reliable. You can work into a bigger build down the road if you even want to still pursue it once you've got a taste of what its like.
-Second is if you're still stuck on doing all these mods, you need to add buying a second car to the mod list. Going that deep, it's not going to be reliable at all. Unless you live somewhere you can take the bus/ subway to work of course.

Sure, the cam is the #1 thing that determines what rpm the engine is happy. The bigger race style cam options will usually have power bands like 3000-6500 or 3500-7000. That's great for a drag car that's going to live up there, but that's above where a street car will spend 99% of it's time. Some issues related to that:
-Lots of overlap and chop at idle is letting good air/fuel mixture blow right out the exhaust as both valves are open at the same time, for a long time at low rpm.
-That makes gas mileage worse as raw gas is going right out the tailpipe.
-That makes tuning harder as the O2 sensors pick up this excess raw oxygen and add more fuel thinking its going lean.
-That reduces power at lower rpm as some of the charge doesnt even stay in the chamber.
-That also can cause jerking / chugging at lower rpm where it almost feels like the car has a perioidic misfire. Some of this can be tuned out with a good tuner, but itll never be stock cam smooth as the cam isnt right for that rpm range.
-As a result, a big cam is usually coupled with a looser converter. That let's you tame some of the drivability issues by allowing you to bypass the lower rpm and get you into powerband quicker.
-Doing that creates more heat in the trans and also gives worse gas mileage.


A ST4 will get you there easily with less of the downsides. TBH though, just a turbo kit alone at 400 whp would be a lot better place to start. Worry about getting these big cams when you've got a trans built to hold the power and when you've got some idea of just how awful FWD is going to be at putting down that much power.

It does get old getting destroyed by other platforms with far less power just because you cant put the power down. You'll also end up likely having to run some kind of drag radial for the time you spend on the street as normal street tires are just going to blow off at that power level. Then you get the fun of replacing tires every oil change or two.

I'm not sure how you justify that either. Feel free to take a poll to see how many people are spinning their stock cam bearings, I'd be willing to bet that number is at or near zero.

No bearing is drastically superior to the others, they're not complicated parts. What does kill bearings are maintenance issues, knock, and machining errors when rebuilding. Hence why stock bottom ends last forever and these people with 'fully built bottom ends' have horrific failure rates despite almost all running the 'better' Clevite bearings


Buick 3800 V6

They're just one example, there are multiple options out there. I'll still stand by aftermarket rockers in general being a waste of money though, especially when you dont have a built trans yet.

I figured I would, cause even getting a week or so off work just to pull, build, and reinstall engine would be difficult.

Would the 3000 stall converter from zzp be suitable, or would you suggest something else?

I thought I'd do something to remedy that which you don't see very often. Following what I've seen two guys up in Canada do, and put a secondary engine in the rear. One of which is Turbo Dynamics Ben who got his purpose built twin engine car, in which both engines were turbocharged, in the low 8s.

I've obviously never built a single engine, so I'm just going off what I've seen online. Which by default should be taken with a big fat grain of salt.

It really is a good option. Takes a TON of stress off of you. When something breaks, you're not scrambling to get it back on the road so you can stay employed.


Depends on your plans for the car and what turbo you're going to run. I've got a 3000 in my monte and love it. It's probably looser than what I should've went with on a whipple car as its spending most of its time on the street, but it sure gets you into power fast.

For a turbo car, it's a pretty good middle of the road selection. But if you plan to do a more track oriented setup or plan to run a pretty big turbo, you may want to think about going even a bit higher.

Do you have any engineering or fabrication training? That's a pretty serious undertaking. I had a high school friend try and build one off a GP body early in his adult life and ended up scrapping the whole project before it took its first trip around the block. The massive amount of time (and money to build 2 full engines and transmissions) is really tough.

If you're serious about going that route (beyond getting proper engineering and welding training), I'd just suggest buying 2 totally stock L36 (NA 3800) / 4t65 combos and getting that to work first. Last thing you want to do is to be fighting engine / trans problems due to mods you'd done on top of bugs from the conversion. Once you've got everything in and working, then itll be easier to start adding parts / building stuff up.