|08-19-2012 05:00 PM|
Don't worry about the pistons being dished. With 64cc Vortec heads you will have plenty of compression,I'm guessing in the 9.25-9.5:1 area.
Evan with 76cc heads you will have a true 8.4:1 ratio with thin head gaskets as per the many goodwrench build up articles.Which is a little low for the L79 cam but not a total mismatch,with your 3.73 + 4spd setup to make up the bottom end.
My uncle has a dished piston stock short block with the L79 cam and 462 fuelie heads(2.02s though)and that motor is plenty stout and snappy for a cruiser.......and sounds nice too.
|08-18-2012 02:53 PM|
Gona run M/T streets when I go to the track. I plan on lightning the car little bit.
Mostly I want to be able to drive it. Had drag cars, I think I want this one to be an all purpose car. Altough I have getting the itch to get back into drags.
I may build Z to resemble a vintage Trans Am car.
I am just getting it running asap. I am going to build a more purpose built combo later on.
|08-18-2012 01:59 PM|
|vinniekq2||proven combination to attain what goal?do you want a 14 second street car? 77 Camaros are a little heavy.are you going to ever use slicks with that 4 spd? any 360 ish HP engine will get you into the 13s if you can hook the car and not break.|
|08-18-2012 01:41 PM|
Picked up a set of 034 bow tie heads.
comp now about 9.8
Im not going to port cause Im gona keep it steetable, and the machine shop did a great valve job I dont wana mess up. They smoothed the combustion chambers is all.
Had a set on a 355shot Chevelle and LOVED them. With the Chevy 140 cam and heavily ported it ran high 11s.
Anyway.... I still have L79 cam, but Im thinkn of going a little bigger now that I can.
Going in the 77 Z with 373 , 4speed.
Any Ideas or proven combos? TOO damb many cams to choose from.
|07-28-2012 09:02 PM|
the old 327 350 hp cam was made for 11:1 cr.
it works best with 10:1+ cr.
the whole thing will work a lot better with a cheap set of flat tops installed.
if useing the 305ho heads be generous with the porting and they will work well.
use a isky 270 mega cam 201271
|07-28-2012 08:22 PM|
|vinniekq2||a modified set of vortec heads that are exhaust side ported can take you to 500 hp reguardless of what short block you use.366/377/383/|
|07-28-2012 08:11 PM|
Thanks guys. I'll check into those other choices.
As far as compression, I was going to cheat and use a set of the 305 H.O. heads I ported.
Not lookn to spend alot in this combo, wanting to either build 377, or go LSX.
All my buddies tryn to get me to convert. Im old school.
|07-28-2012 01:25 AM|
Vortec heads require a dedicated Vortec intake manifold. Older manifolds have a different bolt pattern and the Vortec intake ports are considerably higher so the older intakes cannot be ported to work except for a few raised port single plane 'race' intakes- which you do not want anyway (single plane that is).
The L79 cam wants a lot more compression than you will have. The Summit cam LATECH recommended and BigEd36 talked about above is certainly worth a second look.
Vortec head info.
Here are a pile of dynoed combinations, some w/Vortec heads. You might find something close to what you are proposing.
|07-28-2012 12:42 AM|
|grandpa01||The intake manifold bolt holes and ports do not line up with older manifolds|
|07-28-2012 12:01 AM|
96dually, your 350 short block with factory dished pistons, plus vortec heads is the setup GMPP uses for the 350 HO (350CI 330HP) and CT350 (350CI 350HP) circle track crate engines with GMPP cam #24502476 (.435/.460, 212*/222* @ .050, 112 LSA), available for $112.95 at GM Performance 24502476 - GM Performance Hydraulic Flat Tappet Camshafts - Overview - SummitRacing.com. The Summit K1103 cam recommended by LATECH (.442/.465, 272*/282*, 214*/224* @ .050, 112 LSA) has just a bit more lift and 2 degrees more intake/exhaust duration @ .050 than the GMPP cam, so it would probably work fine with your vortec heads. The GM cam should certainly work as GM uses it with the vortecs. A Performer RPM or Weiand Stealth with 650 CFM carb should put you in that 330-350 HP range. The cam grind gives a wide, flat torque curve, & would work great in your Z28. It has a noticeable idle so you can "hear the cam", but has great street manners and plenty of vacuum for power brakes. Here's the GMPP dyno chart for the 350HO, and a YouTube video so you can hear what the combo sounds like.
|07-27-2012 08:25 PM|
|LATECH||Also search for the term "quench" and any post you read by a guy named techinspector, you can pretty much take as gospel|
|07-27-2012 08:23 PM|
Lots to consider when choosing a cam.
I am thinking flat top pistons would be better as it would raise your compression ratio .
Those heads have a nice size quench pad.
You should read through the past threads by doing a search for related topics. There have been so many threads on exactly your subject.
many factors apply to choosing a cam.
You have a lot going for you allready with the 3.73 and the 4 speed manual.
Search through the database here.
I made my recommendation based on a auto trans equipt machine with a tall rear ratio, thinking yours was pretty much stock. My bad.
|07-27-2012 08:05 PM|
Cant remember on the pistons... been a while, they are just factory.
Car is 4 speed with 3.73s
|07-27-2012 08:02 PM|
|LATECH||How deep is the dish on your slugs?|
|07-27-2012 07:58 PM|
Heads will fit the old intake. Center bolt holes for heat riser arent present on the heads.
Look at the summit SUM 1103 cam. It looks like it will work with those heads nicely in a street application, with stock torque converter and tall rear gears. SUM 1103 Lift is also close to what the vortec max flow/lift specs are too. budget priced too. Just a thought.
Iread somewhere that the vortecs also have a factory 3 angle valve job. Probably what helps the flow numbers as a stock unit.
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