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1996 305 Vortec Vacume and Cam?

  
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1996 305 Vortec Vacume and Cam?

 
archerk archerk
I love my Chevy Chevette! | Posts: 8 | Joined: 01/14
Posted: 01/07/14
05:51 AM

First post so be kind!!
I have a 1996 305 Chev vortec that I am putting in a 32 roadster I am building I have a limited knowledge of motor building and am starting to worry about what I have set in motion after reading all the bad stuff I have been reading about both the 305 and the comp Thumper Cam I already purchased. I live in Australia so need a bit of help from you guys. I will tell you what I have on its way and what I can do about the vacuum problems with the TB350 auto and breaks. And any other useful comments you may have.. (already heard should have got a 350 chev )
SPEC:
cs283 comp cam Thumper cam
(lift int .513 Exh .498)  (Dur.@.05 int 227 exh 241 ) pro comp Roller rockers
26981-16 Beehive valve springs New caps and locks. New roller
lifters & pushrods Welland stealth manifold, Block hugger headers  twin 2.5 exhaust
Holley 4150 street avenger 570cfm carb
Street Fire HEI dizzy
Vacuum canister
Question. Will I have enough vacuum for Trans, carb and brakes or should I use vacuum pump as well.
Too late to
change above so what do you guys think??sorry about length of post.
Kevin

.  

dond1965 dond1965
V-6 Camaros rule! | Posts: 33 | Joined: 12/13
Posted: 01/07/14
10:01 AM

the post length is fine bro, please never worry about such things, for all who concern themselves to reply NEED as much info as possible!! i need to ask, what head castings you are using? from what info i have, my first thought is you want a smoothie of a cruiser that sounds MEAN. the cam you have chosen does have a mean sounding idle and is made just for that reason!! for your small cube combo, i recommend that you use a cam gear drive, and use it to advance the cam [8] degrees. you will have to mock up the engine and check piston to valve clearence with clay. it is possible that your pistons might need the valve relief notches re-machined deeper for the clearence required so the valve heads do not contact the pistons. there should be no need for a vacuum pump. but a large vacuum reservoir may be helpful to operate the power assisted brakes. please feel free to repost any more questions, there are people here who can help with anything you might need to know.... gooday  

archerk archerk
I love my Chevy Chevette! | Posts: 8 | Joined: 01/14
Posted: 01/08/14
07:05 AM

Thanks mate Don't know about head castings ? How do I find out? I started out intending to just stick a cam in but I am starting to get into this motor work on top of building my first Hot rod. I also purchased an older(1976) 305 bottom end from a bloke moving back to the states and am thinking should I build on that using the vortec heads as this has all new parts .not put together still in boxes.
has Speed pro Hypereutectic flat top with valve recesses H534P
Sealed power piston rings ,ACL duraglide 780 bearings,Fed Mogol cam bearings
Melling oil pump, Roller master dual Timing chain, Reco .harmonic balancer
The block is Blue 305,1 piece rear main, bored 30th, honed, decked tunnel honed
Rods resized, crank ground .010/.010, oil galleries oped up, blue printed and balanced. whatever all that means? what do you think I think the vortec heads fit but would have to do something about converting to roller lifters as the block does not have  the threads to mount the bar that holds the lifters in place or is that what the linked lifters are used for ?will have to do a bit of research but its all new to me so Im loving it!. any comments welcome  

dond1965 dond1965
V-6 Camaros rule! | Posts: 33 | Joined: 12/13
Posted: 01/08/14
09:16 AM

heres what i know bro... the one piece rear seal came out in 1986 in the us. some engines that year started using hydraulic roller lifters. in the us vortec heads for 350 cid are NOT the same as 305 heads. the 350 heads are the good ones, and they make pretty good power. i recommend you find a set. look under the valve cover of the heads you have and find the casting number. please post the casting numbers so we here at this forum can help you identify them. vortec heads use [8] manifold bolts. early gen 1 heads use [12] bolts to hold the manifold down. it sounds like you have most of the parts to build the engine. can you confirm the one piece rear seal status of the machined block you refer to as a 1976? i take it your mother thumper cam is a hydraulic roller for a late style block. maybe a machine shop can work a deal with you to get the right block, and the rest of the valve train components you need to run the oem roller lifters. till next time.... gooday  

archerk archerk
I love my Chevy Chevette! | Posts: 8 | Joined: 01/14
Posted: 01/09/14
06:02 AM

Hey Mate I looked under cover number is 12552520   A316 The Motor is a 1996 305 I believe that was the first year of these heads I hear they are better than the older stuff ???
Good on ya mate for posting as it seems no one else has much to add good or bad.  

dond1965 dond1965
V-6 Camaros rule! | Posts: 33 | Joined: 12/13
Posted: 01/09/14
02:09 PM

ill see if i can get some else over here to help.  

dond1965 dond1965
V-6 Camaros rule! | Posts: 33 | Joined: 12/13
Posted: 01/09/14
07:59 PM

ok, got some news... scroll down this page to the bottom. click on the source interlink icon. this will take you to a page of multiple magazine sites. click on chevy high performance. go to forums, then active posts. click on the post with your head casting number displayed, follow the thread. good luck to ya.  

tuffnuff tuffnuff
Moderator | Posts: 268 | Joined: 01/10
Posted: 01/09/14
08:57 PM

Icon Quotearcherk:
Hey Mate I looked under cover number is 12552520   A316 The Motor is a 1996 305 I believe that was the first year of these heads I hear they are better than the older stuff ???
Good on ya mate for posting as it seems no one else has much to add good or bad.


dond got me over here from another site and your casting #'s indicate that the heads are 305 Vortec with either 58cc or 64cc chambers.,.
These 305 vortec heads are similar to the 350 L-31 heads but not quite the same. They are not like the older center bolt "swirl port heads" either.
They have a combustion chamber that is more like the L98 TPI heads 081 and 083 cast iron. The ports are similar to the 350 vortec heads. They use the same manifold bolt pattern and raised intake port position. The stock valve size is 1.84"x 1.50".
The combustion chamber size is supposed to be 58cc but may very well actually be 64cc.
If you don't mind reworking these heads a bit and can get them done fairly cheap, they can be a very good deal.
They will need larger 350 sized 1.94" intake and 1.6" exhaust valves. they will also require a bit of porting and some chamber rework to unshroud the larger intake valve around the chamber wall, thus taking advantage of the large valves.,. they will also need all the valvetrain machining that the 350 vortec heads need, to run any kind of high performance.,. the stock vortec maxes out at .460" lift.,. because the stem seal sits on top of the valve guide.,. retainer and seal interference is to be avoided, with anymore lift.,. machining remedies the max lift issue beyond .500" lift.
They have a lot of potential, by virtue of their fast burn chamber.
Hope this helps.

Vortec On Right - 461 On Left

461Andvortec

Vortec Bolt Angle On Left - 461 On Right

Vortec Bolt Angle

Vortec Head End View

Vortecheadendview

Vortec Intake Is Higher

Vortecintakehigher

My Modded 906 Vortec With Big Valves

Vortec906with202s

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

dond1965 dond1965
V-6 Camaros rule! | Posts: 33 | Joined: 12/13
Posted: 01/09/14
09:40 PM

thanks for helping tuff. this makes me think... ever heard of the bow tie sportsman vortec heads. ive seen only the smallest bit of info. if i remember they are 220 cc intake port. but thats all i recall. know anything else?  

archerk archerk
I love my Chevy Chevette! | Posts: 8 | Joined: 01/14
Posted: 01/10/14
06:11 AM

Thanks Mate  I will show what you said to an engine builder I have been put on to here in Oz you have got me thinking about my cam that has Gross valve lift of .513 Int and .498 Ex . I looked at my 78 block and the head bolt pattern looks different to my 96 so I don't think I can put these heads on that block??I know the 96 has roller lifters and retainer plate that bolts into valley .that the 78 does not have but I believed that if I used lifters with the link bar it would work ?I have some roller rockers on the way Pro comp but have been told to bin em and get better rockers as Pro comp gear is a bit hit and miss ??I was told this Thumper cam (CS 283T )would fit straight in with no alteration but new springs ? This is my first motor job so just after a bit of kick don't expect to much .I will ask more questions before I pick my next motor and parts to use . Not as easy here in Oz to get info or parts I order most stuff from Summit. I guess If I knew if all the parts I listed in an earlier post in this thread would work together I would be happy to see what I end up with because if I have to spend too much on this I would have got a better motor to start with
Thanks for your input I appreciate your reply.Kevin  

archerk archerk
I love my Chevy Chevette! | Posts: 8 | Joined: 01/14
Posted: 01/10/14
06:13 AM

Good work mate interesting stuff.  

archerk archerk
I love my Chevy Chevette! | Posts: 8 | Joined: 01/14
Posted: 01/10/14
06:13 AM

Hey Dond Good work mate interesting stuff.  

tuffnuff tuffnuff
Moderator | Posts: 268 | Joined: 01/10
Posted: 01/10/14
07:11 AM

You might want to try out a free engine dyno and see how your combo works out for you.
Click on link below.

http://www.virtualengine2000.com/

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

joe- joe-
I love my Chevy Chevette! | Posts: 13 | Joined: 01/13
Posted: 01/10/14
09:09 AM

i'm not sure if it makes a big difference, but i noticed comp cams has 2 VERY similar cams.   one is for factory roller;
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=216&sb=0

and one is a retro;
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1258&sb=0

you absolutely must modify those heads to accept that much lift.   i've seen it done 2 different ways.  either machine the guides down, or use one of these kits with special retainers;
http://www.alexsparts.com/valve-spring-kit-sb-chevy-vortec-hi-perf-hyd-flat-tappet/

as for vacuum,...i'd follow Donds advise on the vacuum reserve canister.  what rear gears will you be running?    it would probably be a good idea to use an aftermarket stall converter with your set-up.   maybe the guys can help you out selecting an appropriate size?  

  all the best on your build,
          Joe  
joe-

joe- joe-
I love my Chevy Chevette! | Posts: 13 | Joined: 01/13
Posted: 01/10/14
09:09 AM

double post. Blush  
joe-

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