Okay, I am planning on doing 1.6 roller rockers, but how much of an improvement in power is that really going to have with the stock peanut cam in my LO3? What's the max lift I can run? Am I going to need a chip/tune for this?

 

It'll run fine w/o a tune I did mine and underdrives at the same time. It was a good seat in the pants difference real easy to.

 

Cross multiply then divide to figure out the new lift. Stock lift x 1.6 / 1.5 = new lift with 1.6's.

1.5 1.6
---x---
stock|Y Solve for Y.

 

Educate yourself on rocker arm geometry. Just swapping in different ratio rockers may require different length pushrods. While it may be close enough, you may damage the rockers in the long run.

My suggestion: Find another block and start from scratch. Or since you have already got another daily driver, just start with your block. Point being is that I believe in the approach of matching components and tuning once, rather that an add on here, another later. Take your stock block if the rings are OK, and get heads, cam and rockers. Could do it cheap for 500 or so used.

The 1.6's power improvements will be minimal at best with that cam. You should not have to change the tune for it to run ok, but your stock tune will not take advantage of the upgrade unlike a MAF based PCM.

 

which 1.6's where you looking at aaron

 

Maybe I am missing something here, but it sounds like that because his new rockers may change the correct pushrod length, rather than buying a 25$ set of pushrods, he should buy a new engine block? Did I miss something here.

Running incorect length pushrods will not hurt your rocker arms, it will cause excessive valveguide wear , so you will need to check for it, I do not believe it will be off enough to justify new pushrods, but better to be safe than sorry, checking pushrod length is no more difficult than changing rocker arms.

I do not believe you will see any seat of the pants difference from this, you will gain valve lift but stock heads do not really flow past .400 or so, your only real gains will be from less friction. I do still say it is a good mod, because it may help the car run better now, and if you ever upgrade any other parts of the motor, especially the cylinder heads, then the mod will pay off later.

 

I posted the actual lift changes in my "synopsis" post but here you go...again.

Stock L03-L05 camshaft 10088155 179/194 - .350/.384 109 LSA

Stock cam W/1.6 rockers 10088155 182/197 - .373/.410 109 LSA

as far as a difference when I first put on my 1.6's the car just felt better all around. I noticed a better ability to breathe in the upper rpm's. I know with tuning it would be more beneficial. With the 1.6's you don't "have" to have new pushrods. I know many people who have swapped to them with no ill effect. I have been running mine for YEARS with no problems.

 

Not saying anything more than to think big picture and spend the money and time where you get the best results. $200 on rockers or 400-600 on cam and heads. Or exhaust and tune. If I could go back I wish I had tuned more on my stock L03 to raise my knowledge before the swap.

Correct me if I am wrong, but I thought that the instructions for GMs 1.6s told me that incorrect rocker alignment can move the contact point of the rocker and the valve (or pushrod?). I would be more concerned with running the valve seals out more since they always leak to begin with on L03s. Not a huge concern, just puffs of smoke on start up.

If others are saying it will give ya some SOP feel, go for it I guess. Hey, at least I did not say stop wasting your time with a 305.

 

is there a formula for setting pushrod length.
if you go from 1.5 rockers to 1.6 and then you change the cam from stock to a zz4 - how do you get the right length determined in advance?
i have the zz4 cam so its 474/510 already and i got the pushrods with it as well as the springs.
so is there a formula to determine if i have the correct rod length or do i have to hit and miss with it?
dont mean to hijack the thread but it appears the answer fits into the original problem.
thanks

 

Here is a good tool that I use to determine the changes in rocker ratio, also IIRC duration changes by two or three points up when ratio changes. So if the ZZ4 cam is 208/221 @.50 474/510 then it should change to 210/224 @.50 506/544. I hope this helps.

http://www.thedirtforum.com/rockercalc.htm

 

You could pick up a kit from Summit that has an adjustable pushrod. Use that to roatate the motor over and check that the pushrod stays located on the rocker tip for the duration of lift. The kit comes with instructions that you could download on their site usually.

 

Probably the biggest potential problem is the pushrods interfering with the pushrod slot/hole in the head since the 1.6's move them closer to the valve to increase the ratio.

I would say that the 1.6's wont give you much gain for the money spent, but if they are good rockers such as comp cam magnums, they wont flex as much as the cheesy stock stamped ones do, which helps transfer more lift to the valve.

Youd be better off spending the money on an LT1 cam and tuning equipment. For almost the same money you will get more power than the 1.6's can give by themselves.

 

i also remember reading that the stock stamped POS rockers can have ratios of 1.39 up to 1.52 due to tolerances.. i guess you'd also pick up some smoothness and prolly also power here.
i'd be very interested as to how the stock pushrods (holes) fit with rockers like the comp cam magnums.

 

Does any one know if the summit adjustable kit will be any good for the lt1 cam and vortech heads im using for my car?

 

thanks for that information. that means my springs will max out at .530 and that 544 in the back end will not only exceed springs but anything that i was going to use for heads. maybe someone else is in that same position. you could use the 1.6 for the intake but dont need to go that high in the exhaust. if you do pm me and maybe we can split the cost of a full set of full roller rockers and just use them for the intake.
i called a number of shops but they all want to see you a full set instead of just 8.

 

I plan on using the ZZ4 cam in my the near future but I'll be using 1.6's on the intake and 1.52's on the exhaust. that should put my exhaust at about a .517 lift.

 

Just FYI to all, if any of your combo's exceed .480" lift you will want to have the valve guides cut and the pressed in studs removed in favor of screw in units. An LT1 cam with 1.6 rockers is pushing it on stock heads.

 

Luckily for me ZZ4 heads already have 'em,lol.

 

pm and let me know whey you do and i will go in with you on a set of rockers because you have to buy a full set and you will only need half of them - for the intake, same as what im doing, provided we are looking at the same rockers.

 

Actually I already have them. I've got everything I need to do this but I've just been to busy with work and school to put everything in, lol

 

Hey Shifty. Will a lt1 cam be a worth while swap on a stock lo3? I have to start some place. Found a used cam for $25. anything else needed to swap the cam? What do you recommend? If I spend much more on the car, this year my wife is sure to kill me, but I'm tired of the "slowmaro". Anyone have any power numbers on just the cam swap?

 

Is it worth it, yes. It is a good cam upgrade over stock because the cam is cheap, and using the stock rocker arm ratio will allow you to get away with the stock heads.

However, there are additional costs with the biggest being chip tuning. You will need to invest at least $200 to $300 for the equipment to tune and hours of your own time to learn how to do it.

Other than tuning, parts and gaskets are cheap.

Timing chain - $50 to $100
Timing Chain gasket - $15
Intake gaskets - $20 to $30
Valve Springs - $60 to $100
Tool rental (if you don't have a valve spring compressor or balancer puller/installer)

I must emphasize that tuning is a 100% must. If you cannot devote the energy to tune a cam I suggest sticking to the basics mods such as full exhaust (which should be done before any cam swap anyways) and suspension upgrades.

 

Well Thats a lot of extra stuff just to swap in a 25$ cam. I cant spend that kind of money. I get only a thousand bucks, every two years to spend on upgrades. Only thing the car had in it for the last 3 years was the dash, So I went with interior this time. How sure are you about tuning? I asked two people the same questions (you androbertfrank) hoping for the same
info, but rob just recommended springs. huh. Well if I do had to spend all that cash to swap it, then ill have to just let the cam sit for a while. I am on my way now to buy the cam.

 

I was going to tell you exactly what shifty did but he beat me to it, lol any time you dig into a project there are hidden costs involved. I know this all to well. What looks like an easy cheap job can turn crazy and expense quick if you haven't done it before. Even more things you're going to have to buy that weren't listed is new oil, a filter and a new jug of anti freeze.

 

I did some searching and compiled a true parts list of everything you're gonna need so you can make a "check off list" so to speak.

These are autozone prices. all gaskets are felpro.

Cloyes single roller timing set $25.99
intake gaskets $23.99
Timing cover gasket $9.99
Valve cover gaskets (if needed) $20.99
Manley 22410-16 Springs $79.95 Summit Racing
Manley 23652-16 retainers $62.95 Summit Racing
AC delco PF1218 oil Filter $4.00 walmart
Oil of your choice but I prefer Mobil 1 10w30 syn $26.85 a gallon walmart

The tuning stuff is tottaly up to you in which direction you want to go. It can be cheap or you can get the best stuff you can buy. I got the EBL Flash, ZT-2 WB O2 sensor ( complete kit) and a laptop. That stuff alone cost me almost $1000. Maybe others can tell you what's cheaper.

 

Was this what you were talking about robert:

http://www.zeitronix.com/Products/zt2/zt2.htm

If so, do you tune with it then install a standard O2 sensor when you're done?

Also, for those of you who are reading this thread and have been looking, heres a serial to USB adapter:

http://www.newegg.com/Product/Produc...82E16812339013

 

Well thanks a lot for your help guys. Really helped put it all into perspective.
Rob your the man. Thanks for the price list.

So total cost is around $275 without tuning. I read this mod is good for 25-45hp. I thought that the 25 would be with no tuning.

I dont want to spend the money to burn my own chips, but I know where to get a chip burned for $150, so I wanted to do that. I was wanting to do as much as I could with no tuning, since I cant just buy it all at once.

So heres the next couple questions then. Where do I get the stuff to burn my own chips, that way I can ponder it. Also do I have to have a certain type of lap top? We have a lap top, but its just your standard everyday lap top.

Next question. Is it a must to tune? 25hp is fine for right now. Thats $11 per hp ( with everything else on the price list) with the 25ph gain. Guess I should also add, that at some point I am going to add an open element filter. Does that change anything?

 

Pardon me real quick, just a quick question, why was aaron92maro(creator of thread), or w/e his name is, banned? He seemed like a real friendly guy.

 

He was awful fond of sticking his foot in his mouth and going off at others about it.

I'm a member on 5GO and hes on there now and hes already had one brush with the mods over there.

 

hahahah, lol, wow, I searched all his posts and found the one about the 305 HO or something, LOL hilarious.

 

Yeah... He was just a bit more diehard about the 305 than anyone else on here.

Youth+Enthusiasm+Lack of Knowledge+Diarrhea of the Mouth=Banned

 

Yes it is. Others will dissagree but I suspect it is because they never really drove a cam'd LO3 on the stock tune. If they did, they must have more patience than me. I have driven two. Both drove like garbage. My first LT1 cam swap was 5 years ago and when I was done the car was slower, ate gas, idled poorly, and all around driveability was terrbile. A little tuning goes a long way. stay away from off the shelf chips promising to dial in your tune on the first try from info you supply in an email. Any cam swap in an L03, even with a $20 LT1 cam, must be treated the same way.

 

i thought you only needed those mods if you changed from a flat tappit to a hydraulic roller cam. doesn't a 92 already have a hydraulic roller cam and hence all of those mods? or do i have it backwards, or ami just plain wrong?
i was reading on this last night and with a roller can already in a roller cam swap was pretty simple and you can keep and use your old roller lifters.
so if you go from stock to a zz4 cam there should not be any problem.

 

I'm pretty sure the L03 comes with a hydralic roller cam, that's why the LT1 cam can swap in without changing lifters/pushrods (i think), it may not be best for performance but it'll still work.

 

well im going to use new lifters that came with the cam and the zz4 springs too.
but all of the info about timing chains, etc would not apply to a hydaulic to hydraulic roller cam - or would it?
i have too many miles on my hyrdaulic rollers so im getting new ones too, but the chain and everything else is good and tight.

 

Your 92 does indeed have a hydraulic roller set-up, however you needs those parts to support the new specs of the cam. The timing chain needs to be replaced because they stretch over time. You need new intake gaskets because those are not reusable, you will see when you take them out. The valve springs are needed to support the specs on the new cam. The stock ones are tailored for the stock cam. You need to buy springs that support the LT1 cam specs.

 

so shifty the new chain is simply because of wear not because they are going from a flat tap to a roller. that makes a lot of sense. already know about cant use gaskets stuff but wanted to make sure i was not missing something about needing other things or i misjudged what kind of cam or rollers i had.
you appear to have a good grasp on the topic, so do you suggest getting new rollers or using the same ones - and can you get them rebuilt.

 

You are correct on the timing chain. General rule of thumb is that you never re-use a timing chain with a cam swap unless it has very few miles. Most of these cars have lots of miles and it is cheap insurance to make sure you are getting the proper timing out of your cam. You can re-use your stock rollers pending they are still good. If they are clean and roll freely you will be safe to re-use them. Same goes for your pushrods.

 

You will not need a timing chain if its tight. Most would say to upgrade to a double roller at the time of a cm swap, but if its not broken then dont fix it. Right?

 

You can't really quantify that.
You are going to want a new one. You are going to stress the worn stock one more with your new combo and it is cheap insurance. You will have the top end of the motor all torn apart, the $100 is worth it to have a new chain that is stronger, and more precise.