3400 With 3.4 RWD Head Gasktets

[sanjay]

large port 3100 top ends are the same as 3400..

Thanks Dave..

No Doz..A 3500 top end is not an option. 3500 top end parts are not easy to come by in Canada. When they do come up they are expensive. Bringing them across the border cost a fortune too. A 3500 top end also cause other complication that I don't feel like dealing with like finding a 3500 map sensor & bracket, mounting the coils & ICM, TB adapotor etc... I want to use what I have and what's already paid for.

Dave..yeah $110 is not a bad price for the parts but i still have to pay someone to do the work (~$100) and I still need the 2 "header" manifolds (~$100). Are the gains I'm going to get from this over ported 3400 manis really worth the $300 investment?? Will this setup even clear my rad fan? Again I'd like to use what's already paid for...

I'm not looking for all out performance, just things I can do with the parts in hand and at very little cost. This is in the end a daily driver..

[Superdave]

if it's a DD then i'd just use stock 3x00 logs like you wanted. You could even use the old 3.1 logs to save time on exhaust fabrication. I ran them on my stock 3400 and still had plenty of fun with it.

the flow gains are huge, probably worth 10-15 HP.. but if it's just going to see the streets then there isn't much point to doing all the extra work.

No, the front won't clear the manifold.. you gotta reverse the polarity and move the fan to the front side of the radiator. A slimline fan might fit normally but it looks much better without a fan in the bay IMO.

[sanjay]

if it's a DD then i'd just use stock 3x00 logs like you wanted. You could even use the old 3.1 logs to save time on exhaust fabrication. I ran them on my stock 3400 and still had plenty of fun with it.

the flow gains are huge, probably worth 10-15 HP.. but if it's just going to see the streets then there isn't much point to doing all the extra work.

No, the front won't clear the manifold.. you gotta reverse the polarity and move the fan to the front side of the radiator. A slimline fan might fit normally but it looks much better without a fan in the bay IMO.

No real fab is needed to run the 3400 manis. I already have a pre made downpipe. Just gotta cut my exhaust and clamp it on till i can get it to an exhaust shop or 91Z24's house...

I didn't realize the gains would be that big on a motor that's pretty much stock. 10-15 HP is more than noticeable. I probably still won't do this but I'll keep my eyes open for a pair of header style manis..Too bad you didn't make a second crossover pipe when you made RedBirds...I'd have bought it if they'd help that much..

I don't think the fan is going to fit in front of my rad. I have AC and I plan on keeping it. Besides isn't a puller fan 40% less effective when used as a pusher?? I've never shown anyone the fan setup I have in my '89. I modified the top mounting system to push the top of the rad about 1.5" forward. Then I have 2 12" slimline 1450CFM fans mounted to the rad. I should have made a shroud but stock it doesn't have one so whatever. It cools just fine with only 1 fan running so IF I decide to go the route of "header" manis I can just steal one form there..or get a 14" or 16" one..they're dirt cheap form a local guy.

[robertisaar]

3x00s are like the caddy motors from the 60/70s: have LOTS of potential, but are choked due to the overly restrictive stock intake/exhaust

[Superdave]

Damon is running the stock fan in a pusher config, no overheating problems yet... i've got an actual slimline pusher on mine and it has gotten warm a few times in traffic but never above 210.

[sanjay]

Ok slight update. I finally have the 3100. I went to get it on Friday and that was almost a disaster. The motor was sitting in a body shop so it was covered under a 1/2" thick layer of crud. Then when I got there the owner tell me that the day before his neighbor (2 different mechanics, same building...WTF) broke a rocker bolt on a 3X00 doing a job and he gave one of the rockers out of the engine that was already sold to me to the neighbor. He then starts going on that he should have told me on the phone but he forgot and that if I didn't want to buy it he wouldn't mind..In the end I took it in it's 11 rocker glory anyway for $60CAD.

I tore into the motor on Friday night after a good hose down. The top end and the timign cover are off ans still no signs of whatever was making noise. I'm really hoping for piston slap. I'm hoping not to find bearing issues with the crank since I need it. I'm hoping to have my 3400 bottom end for the 3400/3500 build off the engine stand tonight and this one on. I'm really anxious to see what was making noise. Worst comes to worse I can use the crank out of dying 3.1 but I know for a fact that motor has bottom end issues. I also have another crank that came with the extra 3400 block I'm using for this build but it's way rusted.

In the end I'll probably be keeping the 3100 UIM on the motor just for shits and giggles. Most people knew these cars cam with 3.1's but they can't tell the difference between a gen 2 or gen 3...

Anyway..More on this later when I tear into the bottom end.

[IsaacHayes]

Replace the chain and guide, that probably was the noise. My motor has 220,000 miles, tons of WOT daily runs, tons of time at high sustained RPMs and it's whisper quiet after I did the chain and guide. And yeah anything is better than the log manifolds, they are a huge bottleneck, just the design of them makes it hard for the gas to exit the heads, and that's more work for the motor to push out resulting in loss of power and mpg. Headers are best, but 3500 runner style manifolds flow great, you just don't get the scavenging effect as much.

[sanjay]

Replace the chain and guide, that probably was the noise. My motor has 220,000 miles, tons of WOT daily runs, tons of time at high sustained RPMs and it's whisper quiet after I did the chain and guide. And yeah anything is better than the log manifolds, they are a huge bottleneck, just the design of them makes it hard for the gas to exit the heads, and that's more work for the motor to push out resulting in loss of power and mpg. Headers are best, but 3500 runner style manifolds flow great, you just don't get the scavenging effect as much.

Why change the guide??

Do I have any other choices of timing chain other than the 99- AC Delco? Cloyes Maybe? My parts store can't get me anything.

I'll probably do the 3500 "header" manis in the future but for now I'm good with what I have.