Need Opinions 3400/3500

[sanjay]

I've been looking at what's needed to complete my engine. I'm having a lot of trouble making some descisions because I'm not farmiliar with how certain cam specs & compression ratios will affect engine performance/reliability/driveability etc.

Currently I have the following parts:
3400 Bottom End
3.4 Camaro RWD Pistons
Crank Scraper
3500 Top End
1615 Grind WOT Cam Specs: 280.6/283.8 duration seat to seat 225/227.6 duration .050" .603/.562" lift 111 ICL 111 LSA
Headers
26918 Valve Springs
LS1 Lifter Spring Mod
Megasquirt 2

For a car that will be used primarily on the street and possible become a daily driver will the 1615 cam be too much?? If it is used as a DD it will see some very cold weather. I've heard of great results with the 1617 grind. I'm not looking for help choosing a cam, just a little help to be pointed in the right direction. What it it exactly about my current cam that may not make it street/daily driver worthy?? What specs

With either cam will I have enough engine vacuum for my brakes at lower engine speeds? I really don't want to use an electric vaccum pump. What part of the cam specs gives me an indication as to how much vaccum it will have??

Should I use a 99- timing chain with the either cam or should I go for a single or double roller setup?? I'm trying to avoid the double roller since I don't want to machine my crank. Finding a reputable machine shop in Canada is not so easy and because they are few and far between their prices are astronimical.

With either cam what size throttle body & exhaust should I use? My current headers have a 2.5" collector but that can pretty easily be modified. My

I have also been looking into the Camaro 3.4 RWD head gasket to bump the compression ratio up to 12.35 I believe. I know I'm getting closer and closer to piston to valve clearance issues with the 1615 cam, probably not with the 1617 but that aside, is this too much compression for a street motor running on 91 octane?

Thanks in advance..

[sanjay]

No replies..I'd even appreciate some links to articles I can read so I can learn this all myself..

[Superdave]

it all depends on your tuning abilities, tuning for a big cam is usually a pain in the ass. Often times you'll end up (at least in OBD1) maxing out the VE tables and then having to change the BPC and start over from scratch. There will always be bucking at low RPM's/light throttle and sometimes in decel. You can usually tame it via the spark advance table though.

I drove mine last week while my trailblazer was in the shop, other then being loud and riding like a dump truck it did pretty good.


As for idle vacuum you can calculate the amount of overlap the cam has (time both valves are open) and guess at your idle vacuum. http://www.empirenet.com/pkelley2/Overlap.html

i use the 2nd example they show there.. your cam has 60.2 degrees of overlap compared to mine which has 70.45. You should pull about 10-12" of vacuum at 1K RPM. That's fine for brakes and accessories, just make sure to have the vacuum ball hooked up. The 1617 grind has around 50 degrees of overlap and does fine as well. I haven't had any problems with mine pulling 6-8" at idle.

I'd use a 99 timing set, 65-70mm TB, 2.5" mandrel exhaust with a good flowing muffler.

I would stick with the stock FWD gaskets, but ROL makes a nice graphite 3.4 headgasket that's .045" compressed. That would get your quench close to perfect but like you said, piston to valve clearance becomes a problem. buy a pack of tootsie rolls when you do the assembly use them to check how close your clearances are.

[SappySE107]

You will need to take .100 off the spring seat pockets on the heads to run those springs.