Reborn756

Howdy folks! Reborn here once again coming by to beat a dead horse!

So, my 305 is slowly heading down hill. I'm going to take care of as many minor issues as I can to push it a bit longer, but I'm looking to possibly begin my new engine build sometime early next year.

For those of you that checked out my previous post some months ago, you know that I want to take an L98 block, destroke it using the crank from the L99 v8, and make myself a 302. I've found a L98 block at the local scrap yard for $100 bucks. It may need bored, and if this is the case I'll actually be running a 305CI engine (302 bored .020 over).

I've already got the rotating assembly figured out. What I need help with now is the specifics on the rest of the combo. Things like cam choice, head choice, etc, to reach my desired power numbers. I would like this bad boy to be right around 400 hp and 400 ft lbs. The powerband needs to remain reasonable for the street, and it will need to run 87 octane. I'm looking at keeping it around 9:1 compression. I have a "budget" build I casually tossed together that someone can run through a desktop dyno and adjust with their own suggested parts if anyone it interested in doing that.

I've had overwhelming help from this community some months ago when I first proposed this idea and was trying to figure out if the thing would even work. Now's the time to work out the specifics. I've been both on ChevyTalk and PontiacForums, and I must say you folks here are the best and most insightful crowd I've seen so far. The people over at ChevyTalk haven't been much help, and the few people on the pontiac forums that acutally responded to my post just laughed in my face and questioned my "expertise". You folks here were great to me before, so I figured I'd ask you all again.

Thanks in advance folks!

aliceempire

iTrader: (14)

I think you may need to adjust your goals. You want a low compression, small displacement, low octane drinking, low(er) revving engine to make 400HP naturally aspirated....on a budget due to you not expecting to keep the engine long as you were thinking in the last thread. That's a tall, if not impossible, order.

My suggestion would be to do something closer to what I had in mind when I was originally stuck in a displacement limit, scrap the L98 block idea. Use an LT1. Have the heads ported by Advanced Inductions or Lloyd Elliot, stay somewhat mild on the cam 212-224 duration, keep compression near 10.5ish. Then expect closer to an honest 325-350 HP.

I wouldn't get hung up on HP numbers, the overall performance of the car outweighs the engine HP. And if you're staying under 5k rpm, the area under the curve is much more important, specifically on the street.

Reborn756

Thanks for the reply aliceempire, and good to see you again!

I should also probably point out that I'm not looking for 400hp/400 ft lbs to the wheels. Just at the flywheel. That may make my goal a bit more reachable.

what exactly are the differences between an L98 and an LT1 block? I've done a bit of reading, but maybe you can put it all into plain terms for me. I really wish we had a desktop dyno professional around here that could use their knowledge of the softwares to help us all out. I've played with one myself, but without knowing if I'm setting all the data up right, I can't be sure if the outputs are accurate. If I am using this darn thing right, then I've (barely) hit my numbers while maintaining 9:1 compression and a peak of 6000 RPM. Like I said, who knows if I have this thing set up right though.

aliceempire

iTrader: (14)

I was assuming you meant at the flywheel. The HP numbers aren't as high once you add in full exhaust and accessories. Magazines and desktop dyno's don't add those in so the numbers are superfically inflated. Again, don't get too hung up on power numbers. Worry more about the power curve being where you will use it.

Biggest difference in the LT1-L98 blocks are the coolant passages as the LT1 has reverse cooling. But that's not the only real advantage of using an LT in your build. LT's are cheap, use alot of the same parts, will bolt in the exact same place as a SBC gen 1, have good flowing heads right from the factory, have an intake that aims for your intentions, run higher compression with little issue (due to the reverse cooling), and aren't any harder to wire up than any multiport EFI SBC. Disadvantage is the optispark. They do work fine but the computers are outdated, high rpm's tend to make them more problematic, aftermarket optical sensors SUCK. But the opti is overcome-able by either retrofitting an older style distributor and older efi, going carb and using an older distributor or going 24X LSx style computer.

Added note, you're probably punching in numbers for camshafts with much more duration than 9.0:1 compression will be friendly with, another reason you'll want it up higher.

obeymybird

iTrader: (4)

I have built the same motor your looking at wasn't a bad motor it would rev to 7000 and you had to twist it that high to make the power I would say it was around 300hp bottom line it was nothing to brag about unless your on the highway looking for a top speed run. A 350 with the same amount of work and money into it would have made for a better all around choice. On a side note I don't see many third gens running around the Shore any more seen my old T/A with the ram air hood siting down town by the river only other T/A I can think of is the dark red one I seen sitting by the police station.

Reborn756

That dark red hunk of crap is my TA! Good to see another TA guy around town here! You have any pictures of your old bird? Love to see it.

Do you know any of the McHenrys from Avis?

obeymybird

iTrader: (4)

I don't have any but the car is in town I have no clue who the owner is now. You cant miss it cause its a sharp looking T/A silver paint 17'' chrome 5 star wheels 4th gen wing and the hood sets it off very nice. I might do they live in south avis or did anyway?

Reborn756

Did it sit a little higher than normal because of the rims? I've seen a nice silver one like that around avis once or twice.

Not as long as I've been alive. We've all lived in upper avis. I have an uncle Doyle and Danny, and my dad is Darryl

obeymybird

iTrader: (4)

Doyle did he use to work at RS automotive many years ago? its called woodys garage now. My dad owned the napa auto parts store in town he closed it down and retired.

Reborn756

I'm not sure. He very well could have. Many, many years ago he actually owned his own shop. That was back on the river road if I recall. I'm too young to remember that, just the few stories I've heard.

obeymybird

iTrader: (4)

I doubt you ever seen my Camaro its blue I almost never drive it needs inspected but im always working on it.

Reborn756

Probably not. I only know of two third gen camaros around here: the Teal one behind the avis firehall, and my cousin Stevens black one that he's working on

obeymybird

iTrader: (4)

Let me know when you got some free time I would like to look over your T/A

Reborn756

I'd appreciate that! She's in rough shape, but once I'm done with it she's going to be nice. First step is passing inspection this month. Next step is replacing that hunk of garbage 305.

There's a valuable lesson to be learned here: Don't by a car that's had an engine swap done by illiterate rednecks

obeymybird

iTrader: (4)

LOL very true but there everywhere around are area just like VW and trucks.

Reborn756

Ain't that the truth.