did lots searching, but wanted to start a fresh and up to date thread. the plan thus far includes
os valves,drill, tap, and install sbc rocker studs, 1.6 roller tip rockers, mill and costom pushrods. main question i have is does andbody have p/n for os (1mm) vaves. any input and ideas are appriciated.
ps, pics of last 2.2 build
http://www.j-body.org/forums/read.php?f=46&i=444167&t=444167
you don't need to drill and tap the rocker studs. Learn from others mistakes (Me). ARP make a stud just what your looking for. Do a search under the rocker thread and you will find the PN.
THANKS FOR THE TIPS, HERES WHAT I ENDEND UP WITH. GOOD FOR SHAVING 1 SEC OFF IN THE 1/4. WENT FROM 16.93@82 TO 16.01@87
PARTS-
CUSTOM MANLEY VALVES (1.0 MM OS HEAD) (.090 OS STEM)
ARP ROCKER STUDS
CUSTOM MANLEY PUSHRODS
LS2 SPRINGS
COMP CAMS 1.6 ROLLER TIP ROCKERS
WORK TO HEAD
PORTED
MILLED .050
CLEARANCED HEAD FOR PUSHRODS
CLEARANCED PUSHROD GUIDES
ANGLE MILLED INTAKE SURFACE .020
http://s300.photobucket.com/albums/nn2/firebird327tpi/?action=view¤t=226.jpg
what is the part number for your pushrods
3910 was the Manley. part number. These are 7.625 3/8 .080 wall hardened pushrods. You won't be able to use this part number unless you do everything I did. Pushrod length changed for several reasons with this head. It was milled. .050, longer valves, and different rockers. If you've made changes that require different pushrods, u will need to check for proper length with a pushrod length tool.
Who made your header?
--------------------------
NCR-SCCA
Obx. 4-2-1 header. Polished stainless. Nice piece. Got it off eBay for 160
Nice setup? How did you calculate the pushrods length ? I believe mine are a bit too long.
I used a pushrod lenght tool. It basicly a pushrod that unscrews untill thw desired length. Then you measure how long the tool is and order that length
but with aftermarket rocker rollers, there's not a set distance to tighten the rocker studs down, so would that method still work? If I keep loosening the rocker arm nut, I can keep growing the pushrod length to get to the rocker arm, right? At some point, it's going to be so long that when the valve opens, it will hit a piston.
Or am I not understanding something?
Yes this method works on any pushrod setup. Heres my attempt to explain this step by step how i did it. Before i completely assembled the head i installed the valves with checker springs(regular valve springs can break the tool) then with the head gasket on the engine, lay the head in and snug it down, u dont have to torque it down. Adjust the tool close to the legnth u think it needs to be, install it like u would a pushrod. Install your rocker and adjust the valve (this is where adj rocker studs come into play) it will take several times but what you want is when u roll the motor over the contact area of the rocker should start at one side of the valve tip and as it pushes the valve open it will slide across the center and over to the other side of the valve tip. Hard to explain without an engine to show it on
Ohh, ok. after reading that like 5 times, I think I've got it, so the roller tip should start on one side of the value, and then when fully open, move over the center of the valve and to the other end of the valve. And so when it does that, it's the correct length??
I think i'll need to get this tool, because my hardened pushrods may not be right, I've had a valve slam into a piston 3 separate times now and snap off, so after 3 rebuild's i'm starting to suspect something... It just breaks under normal driving, aka going down the street at 20mph, barely any throttle.
Pushrods too long wont cause piston to valve issuses. If there too long and your using stock rocker studs(that torque down to 22 ft lbs and stop) it will cause the valves to hang open and the engine probibly wont even start, if it does it will run like crap. If you've swapped out for adj rocker studs then u should be able to adj the valves even if the pushrods are a little short or a little long. Valvetrain geometry wont be ideal but a longer pushrod doesnt open the valve any more. What all has been done to this troubled engine
Just my little 2 cents when you do all your head work and if you do any port and polishing make sure you get that thing tuned cause you will be running rich as hell
Mines been done for awhile, no codes and o2s look fine. Cant tune it anyway, still have the 96 ecm
Jonathan Creel wrote:Just my little 2 cents when you do all your head work and if you do any port and polishing make sure you get that thing tuned cause you will be running rich as hell
Is that based on experience? Why would it run rich? wouldn't the o2 sensor correct air/fuel mixture, even if it's narrowband? I've got heavy mods on stock computer, stock tune, and it runs great. It can probably be improved with a tune, but it isn't rich.
Yes this is from experience my car has been fully port and polished with 1mm oversized valves for about 4 months now and i havent gotten it tuned again since i put the new head on. Its not so bad that i cant drive the car it doesnt smoke or anything like that its just when i get off the gas you can hear it rumble from all the unburnt fuel. Not saying that he has to get it tuned but it would just help get maybe a couple more horses but as he already said he can tune cause he has obd1.
A tune with mine would no doubt help, and a ecm-wire harness swap is a want. If for nothing else to get rid of the rev limiter. I never knew or cared if it had one or where it is set at from the factory because the engine was useless past 6000, but now i know where its at, 6300 and it hits it hard. My goal here wasnt to make a fast car, just to make this one a bit faster. I bought this car about 8 years ago for 500 bucks and its been the best damn car ever, and when i saw the head gasket start to leak, i found another head to work on while i still drove the car. I work at a very well equipped machine shop and build engines all day everyday so of course i made some changes (btw thanks to joebiv and the org on the part number help) the changes have worked well, made the car a bit more fun to drive. I wasnt sure how noticeable the changes would be but it made a difference, almost a sec in he quarter. Still not a hot rod, but worth it
