IDriveA95Z28

I have 191,596 miles on my 1995 Z28. Stock LT1. I would like to modify my engine, but not to a crazy amount of power. It is my daily driver. I honestly want a engine that handles well as a daily driver, gives of a nice sound, and power I can handle. So would it be best to do a rebuild on the engine before modify the engine in anyway? Because I don't want to be the dumbass to drop money in a engine with so many miles and risk being without a engine let alone a car. I am currently doing exterior fixes on my car, so I am not going be doing this anytime soon, mainly because of how much it most likely will be. But the main ideas for modifying is short air ram intake, headers, camshaft etc. Those are the big things in my opinion. I know someone that can rebuild it for me but what is it that I need to ask him to do? Like what do you guys say when you go to have to engine rebuilt? Do you go with what you have in mind what you want done, or do you go there and discuss there what you want done? I don't want any modifications to the engine if I rebuild it. Maybe a few performance parts here and there if that makes sense, I don't want a stupid amount of power, I am still learning my car. I just want a engine good for daily driving gives me decent power to handle, and gives off a nice sound. HONESTLY I am not one to race often at all, I am a very cautious driver, maybe the occasional launch, speeding, pull up to someone and speed off and see what they do. But other than that I drive it to school, to home, back to school, then friends house. On the typical day I drive 20-40 miles mixed with city and freeway miles. I drive her on sunny days to cruise. I am move the guy to keep their car looking great and clean other than speed. don't get me wrong, I love to go fast. But I like looks and sound more than speed, yes I know I should power to back up the sound, but I need a car I can handle. This will be my daily for a couple years into college till I buy a second car and put the Camaro in the garage. I tried to put all that I thought would be helpful for your guys to help me understand what I want, If there is anything else I should state just let me know. Sound wise, I would like the nice lope at idle and nice deep aggressive sound while driving.

Fatdog2

If the engine is running fine,I'd leave alone for now.Some previous members racked up around 250,000 mi.on the LT1.You can get re-manufactured short blocks I think for about $3000. or so. But then there is installation,putting on the old parts or buying new or rebuilt.Then there are the heads ect. It adds up fast.Fluid changes are the secret for longevity.It might be cheaper to find a good low mileage f-body like I did.Paid $5,500 for an original 39,000 mi car (auto trader),the drive train is sound but I've spent another $3-4000 on replacement and upgrade parts and still have shocks and front brakes to do.I want to get my heads ported but monies are going other places.So make a list of what it's going to cost to rebuild the car you own, or replace the car.Hope this helps.My02.

IDriveA95Z28

Thanks gor the advice fatdog. The only reason i thought about doing a rebuild is because i want a different cam, so i can get a nice lope and some power. But i dont know if the engine can hold a new one. Engine runs great right now.

Chimera96

don't put a cam in a 195+k mi motor. rebuild it and do a cam

headers and lower rear gears will "wake up" the car. New valve springs, 1:6 RR and a PCM tune would be the only thing I would do to a motor with your mileage

IDriveA95Z28

Chimera, so im not fully knowledgable in ratios and internals and such. so what would new valve springs do?? what is a 1:6 RR?? I am assuming that RR stands for roller rockers. which is under the heads and moves the springs? and if im correct, the PCM tune is just a certian tune to run through the computer to have car run a certian way. which im assuming there are a lot of tunes to choose from..?

Chimera96

if your valve springs are original or even have 100k mi on them they are way tired and likely only allow the motor to rev mid 5k rpm without valve float. They are a wear item in terms of performance ability. A quality replacement set like Crane 10308-1 are a drop in replacement.

RR= roller rockers. your car has stamped rockers in 1:5 ratio. 1:6 "roller" rockers will give your stock cam a little more lift=performance and the new valve springs will allow your motor to rev higher without valve float=performance

tune would be something to improve performance. There are several companies offering "mail order" (you mail them your PCM) tunes. Typically this involves installing a 160 degree thermostat so they can lower engine operating temps and ad more timing=performance.

if you are not familiar with replacing valve springs, installing RR and lashing valves, don't do this yourself

One thing to consider when modifying a high mileage motor, and yours is, adding performance components and thus revving the motor higher will tax an already "well used" motor and shorten its already near end life cycle

IDriveA95Z28

I know several people who can help me do this. One who is valve grinder and builds engines. The other just rebuilt his lt1 for his 93 firebird. How much is a good set of valve springs? And how much would roller rockers?

Chimera96

good you have experienced assistance.

A good drop in spring is Crane 10308-1 kit. Some will say Comp 26918 bee hive springs...I would stay away from them after running them myself. Comp Pro Mag RR are very good but will require trimming the drip baffles on the valve covers. Crane Gold Narrow Body 1:6 x 3/8" RR do not require any trimming of valve covers. The trimming is very simple if you do go with the Comp RR. You need Self Aligning RR or if you run Non self aligning you will need hardened push rods and guide plates. Your experienced friends should know all of this if they work on LT1's

Summit or Jegs will have all of this stuff

also get new valve stem seals when replacing springs. Felpro Viton seals. Most auto part stores will have them.

IDriveA95Z28

Okay cool, thanks for the help!

Injuneer

The rocker ratio is expressed as the distance the tip moves (lifts) the valve, divided by the distance the pushrod moves the other end of the rocker (= cam lobe lift). This would be either a ratio of 1.5:1 (typically called 1.5X) or 1.6:1 (1.6X). You can get larger ratios, e.g. 1.7X, but there are limits to what is practical.

IDriveA95Z28

It sounds like this would only be usful if im running the car a lot. which i dont do often. but it would be nice to replace old parts.

Chimera96

with 1:6 RR on an otherwise stock motor would give you around a 10 hp gain. More important is replacing valve springs on a motor with your mileage as they are a wear item

Given you take of the stock rockers to swap springs, installing RR at that point is often done

IDriveA95Z28

So it will be beneficial for me to replace the springs and RR. I also think one of my lifters are broken or something because when my engine is running at 3 grand or higher, it sometimes gets a clacking sound near the driver side exhaust manifold. I asked my mechanic how much it would be for him to do the RR and springs and possibly a tune, he told me he would put some numbers together.

Chimera96

you don't "need" RR but if you are doing springs your stock stamped rockers need to come off. There should not be any additional labor $ to install RR if the shop is doing springs

so you have "clacking" sound around 3k RPM.....well a lifter "could" be making noise but it is likely a result of something else:

broken exhaust manifold bolt (side you hear noise from)
lose rocker

If you are providing the parts than the shop will just have labor at x$ x how much per hr

IDriveA95Z28

Ah okay, thanks!