GTA50

I've got the engine out of my '89 Firebird and am just getting ready to send out the block and heads...

So, for the re-build, I'm thinking about "waking it up a little bit" but not to hurt driveabilty or fuel economy as it is my daily driver. Do the following mods make sense? (I've already searched the threads and this is my summary)

Port and polish heads and plenum
260 grind cam (with 916 springs and roller-tipped rockers)
Double roller timing chain
Headers
K&N air filter and CAI
Cat back exhaust

Any need to think about different pistons (i.e. forged) or different injectors?

Thanks.

firstfirebird

iTrader: (3)

Use a 3.1 crank and pistons to up your displacement a little, or use a 3.4 with your intake/exhaust.


Yes your list looks good so far.

forkvoid

iTrader: (1)

I'd like to thank you for actually searching. You're one of the more awesome people with questions, because you already searched.

2.8RS

iTrader: (5)

That's a good setup. I'm running that same setup right now and so far I like it. I need to go back and fix some things that I may have messed up.

GTA50

Thanks for the input.

firstfirebird:

I've thought about using the 3.1 crank and pistons to up the displacement, but I would have to buy them new and I'll have to check on the price. Regarding a 3.4, I thought about that, and actually searched, but in my corner of the universe, they are rare and GM doesn't stock a longblock any more for that size.

But I do have a question, if I was to go with 3.1 pistons (and since I have a set of rings for 2.8 pistons), do the 2.8 piston rings fit a 3.1 piston?

forkvoid:

Thanks for the compliment. Searching the threads is easy (and doesn't cost money) and I have no wish or the money to reinvent the wheel!!

2.8rs:

I'm curious as to the problems you're having. Were they related to the setup or to something else?

Also, one other question, with the 260 grind cam and the 916 springs and roller rockers, do I need to do anything different on hydraulic lifters and pushrods?

bl85c

iTrader: (2)

You can't use the 2.8 rings w/ the 3.1 pistons and you can use stock pushrods & (new) lifters w/ the 260 cam.

2.8RS

iTrader: (5)

My problems were related to bad valve adjustment on my part. The car runs like a top now. Just use new lifters and you will be fine.

GTA50

Thanks guys! I'm replacing the lifters and rods anyway as the engine actually has 425,000+ km on it (doesn't look it thought - regular maintenance and highway miles LOL). I took the block, heads and plenum into the machine shop and lo and behold, he had a 3.1 engine....so, I'm also following firstfirebird's suggestion to use the 3.1 pistons and crank in addition to my first list of mods. The extra cost will be about $300 (parts, balancing, machining, bearings, etc). He also had a 3.4 block but that would have been an extra $900+ - just a little out of my rebuild/overhaul budget.

After this engine is all together, I'll have it dyno'd and see what it ends up with. I'll keep you posted.

Thanks,

Gary.