Mike.

iTrader: (1)

I blew the head gasket in my 97 T/A a couple days ago. Luckily I caught it really early and the oil was fine. I'm in the process of taking it apart now, and I want to have the heads checked and gone through before I put them back on.

So I have these questions:
What all should be replaced while I'm having the heads checked? Valves? Lifters? Unknown mileage on the motor.
If I don't want to change my cam, can I still install roller rockers?
I was looking at 1.6 rr and lt4 springs with my stock cam, but I'm new to this area. (I read the sticky but it's mostly concerned with cam swaps.)

Rob94hawk

iTrader: (1)

You can install roller rockers. How many miles do you have on the odometer? Might want to replace the springs too.

Once you pull the heads you're pretty much halfway there for a cam install.

Depends on your budget how far you want to go though.

Mike.

iTrader: (1)

180k on the odometer but it was swapped sometime in the past before I bought it. I don't wanna take on too much right now with all that's going into getting it running good again. (doing my ac compressor while it's torn apart.) Will definitely get a cam in the future but if I do it now I won't be satisfied with the cheapo that will go in there.
Will the pushrods have to be changed to accomplish the change to 1.6 rr? Someone told me I'd have to re-measure. Another thing I failed to ask is if they'll fit okay on the stock studs.
And what do you think of lt4 springs? I know they're weak for cams but on a stock car?

fex77k

iTrader: (2)

You have to measure anytime you make changes. Since someone has been in the motor before you can't be sure what length they really are. You don't have to but one just borrow it.

Rob94hawk

iTrader: (1)

Measure definetly. Might as well throw some thinner gaskets on as well for a small bump in compression.

96capricemgr

iTrader: (1)

LT4 springs and 1.6 rockers is a good idea, I would go ahead and do 7/16" studs with isky adjustable guideplates and 7/16" stud rockers that way all that is bought once and can be reused with a future cam swap.

The pushrods I wouldn't worry about, technically yes you should measure but from a practical perspective you aren't changing things that much. The LS motors are NON-adjustable and pushrod length gets a lot less forgiving and that is likely why you were told you would have to measure.

No not even consider changing valves unless having substantial; professional porting done, which I would not do with a stock cam. If this engine was a 97 then it is likely 561 heads that are much less desirable for porting anyway.
Lifters I wouldn't screw with unless you find a problem, the replacements everyone PRETENDS are better have a LOT more failures than original LT1 lifters.

Mike.

iTrader: (1)

Thanks for the responses guys. For the time being I've decided to use the parts I have and get it running before I go for any upgrades. I'd hate to drop the money in the top end and need it elsewhere.

I pulled the drivers side head today, and there was coolant in the number 7 cylinder. On this same head the banjo bolt for the steam pipe was on so hard I stripped it while trying to get it out with the head on the car. With the head off I managed to get it out and it was completely packed with this rust colored mess. I don't think it's a coincidence that the gasket failed on that cylinder.

96capricemgr

iTrader: (1)

If the steam pipe fitting was so clogged it let air pockets stay in that head then yeah that could contribute.

quik95lt1

iTrader: (7)

i think youd be crazy not to put a set of lifters in it while your in there....dont be afraid of the ls7's everybody gives them a bad rep ive used over 10 sets and have never had an issue with a properly set up valvetrain

Rob94hawk

iTrader: (1)

Hell, might as well do a cam change. Half of the work is done already and it's the hard part too.

96capricemgr

iTrader: (1)

I should say I don't think LS7 lifters are inherently bad, BUT at the same time we have to combat the myth that they are a magical upgrade and it is pretty clear we do see a higher failure rate with them than we did original LT1 lifters. Not saying that failure rate is 100% or anything but it is higher than the original LT1 lifters.

If I needed new lifters and only wanted to spend $150 or less then LS7s would be what I would order, but I wouldn't go pretending they are a magical upgrade.

FWIW with the 4 different gen 2 SBC vehicles I have owned plus a couple junkyard engines plus friend's cars and such I work on I have never seen a lifter failure reusing originals.

quik95lt1

iTrader: (7)

reason your seeing more failures is there are more and more agressive cams out there with more and more morons setting them up wrong then blaming the parts........ls7 is a better option to the lt1 lifter they tend to handle higher spring pressures much better than the older gm lifters and 90% of cams now a days are running bigger spring pressures espically due to some companies designing irresponsible lobes and calling them "street" cams....are they a miracle upgrade? no i agree.....but no one should be afraid of them by any means......they ARE a MUCH better alternative to the prior gm lifters let alone ones with high mileage on them when the heads come off my gto those will be going in for sure

96capricemgr

iTrader: (1)

I agree with you on lobe profiles to a point, there was a time when double springs were always the answer and beehives are very common these days so they have in many cases reduced spring pressures.

Even when Bauer was selling a lot of square lobe cams I remember seeing a lot of spring and guides destroyed but not so much lifters, even remember seeing cams eaten by the hard rollers bouncing on them without hearing lifter failure.

Mike.

iTrader: (1)

I dropped my heads off at the machine shop today. Should have them back by Thursday.
I have all the mating surfaces cleaned and ready to go.

Should I clean the top of the pistons or am I looking for trouble thinking about it?
I googled it but there's no definitive answer.

SS RRR

iTrader: (2)

You can clean them with mineral spirits or brake cleaner and a steel or brass brush. The brush won't hurt the pistons. Carbon is pretty easy to get off this way.

Mike.

iTrader: (1)

I just got my heads back and I'm sort of confused. This is my first experience with a machine shop, and to me it was kind of shady.

When I got there to pick the heads up there was a bag taped to them with a broken valve spring. The guy said when they went through it they found it broken.. The car ran perfectly fine before it started blowing the white smoke out of the exhaust. Is this not strange?

96capricemgr

iTrader: (1)

15yo valvesprings on a "performance" car not really a shock. Not terribly common if it is indeed the stock cam but nothing unbelievable or anything.

Mike.

iTrader: (1)

I'm not surprised it broke, I'm surprised I didn't see a noticeable change in the car's performance?