chadroosa

iTrader: (14)

i have a 98 z28 with 132xxx miles, i want to upgrade cam, heads, and intake, and supporting part...but dont know if i want to go through with all that on the bottom end with so many miles.. if i do rebuild bottom end ill keep it stock just do new bearing and rings... my car is all street, no track... or just upgrade top end... also if i do complete rebuild what all machine work should i get done? thanks in advance

PREDATOR-Z

IMO with that many miles i would rebuild the short block, send your stock heads to AI for a refresh (valve job, check valve guides, install new springs matching the cam you wish to run, a friendly street cam like a 224/228 or 224/230) keep in mind you'll need a professional tune).

dr_whigham

iTrader: (49)

I'm going to cam my LS6 with 149k. Runs like a champ.

If I was you I'd just upgrade to Katech rod bolts being that those are the known weak link in a 98. Compression / Leak Down Test should tell you all you need to know.

BIG_MIKE2005

iTrader: (116)

Honestly you wont know till you tear into it. Unless its showing signs of needing a rebuild currently. My stock short block was in great shape when we pulled it apart with 100k on it. Still had the factory cross hatchings in the cylinders & even the timing chain was still tight to my amazement. Its been together for about 3yrs now & 70k miles. I'd like to rebuild it this winter though just for piece of mind.

Gunslinger09

On the 97-98 block you cant re-hone the cylinders because the walls are so thin. So all you really can do is overhall the motor with fresh stock rings and bearings. You can use all new ARP fasteners to get some peace of mind there since as was mentioned before rod bolts can be problematic on 98s. Also take the heads and get a good multi angle valve job done. You could for cheap do a simple port job on the heads(grind the casting flash out of the intake and exhaust runners and smooth and polish them with a Dremel) and upgrade to 2.02/1.60 valves while you get the valve job done. Then just add the cam and supporting hardware you want. That would get you a nice tight good running engine that would make plenty of power for a street/strip car. Don't worry about throwing huge money at the motor and replacing everything with all forged pieces unless you are going to all out race the car.

BIG_MIKE2005

iTrader: (116)

If you use ARP rod bolt be sure you get the stock rods checked. If you use Katech your ok without messing with it.

chadroosa

iTrader: (14)

thanks for the input... so if my cyl. walls are scratched im pretty much screwed, was wanting an ls6 intake, some 243s.. wondering if i should just find a newer engine to build on and just keep this one of a cool project down the road...

BIG_MIKE2005

iTrader: (116)

All depends on how deep your pockets are in the end. If on a budget you can probably rebuild the current engine for around $1500 (all new bearings/rings/gaskets/bolting). If the scratches aren't bad a slight hone might take care of it & for new rings your gonna want a fresh hone anyhow.

Gunslinger09

The best thing to do is a compression and leak down test first. If that's all good you can just do your top end and replace your oil pump with the cam swap while you find a new block to rebuild over time. With maintenance these motors last damn near forever.

chadroosa

iTrader: (14)

cool thanks for the advice... looks like i have a starting point

mjs1012

iTrader: (36)

You should be alright. Do everything now and if the motor lets go down the line rebuild it later.