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Headers

R

rpounds

Guest
Wondering what headers, brand, type, size . . . shorty, block huggers, 1 5/8, 1 3/4, etc. that everyone is running. I know there is some debate over shortys vs. equal length tube . . . I don't really want to start an arguement over that. I'm more interested in what you are running and why.

Thanks!

Ron
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
Ron, I've got the headers from TPISpecialties simply because I heard somewhere that they're supposed to fit with no problem, and the coin toss showed heads. (I didn't know who to go with. :L)

I haven't got the engine installed yet so I can't give you an idea of their breathing capabilities, but I'll be running 1 3/4" primaries with 3" collectors on a stroker (417 cid) small block.

_ken :w
 

80convertible

Well-known member
Joined
Jan 26, 2001
Messages
416
Location
Asheville, NC
Corvette
1973 converted to 1980 custom convertible
I've got dynomax ceramic coated headers. They were pretty easy to install and fit well. The only real problem is the less than thick flange. I can't get my passenger side to seal, and I think its because its warped. But then again, they are not very expensive. You get what you pay for. I would recommend paying a little more to get a better quality header with thick flanges.

Regards,

Jim
 
T

tacoed

Guest
HEADERS

I put my head in a few books last yr when I started to build my engine & I much like you had many questions so I turned to a pro( old SMOKEY) who just passed away a few months ago. I think I will go with his advice.. Full length 2-1/2 inch For a some what built 350/383... (depending on your HP, cam, )& sm blk vs big blk. use a cross over mid way back of the system and go with a tri pipe type set up i.e. one with a scavangeing effect, I will go with a 2-1/2 inch coated AfterBurnner headers with a cross over just behind my trans cross member it should be good for several Xtra HP. then put on a set of cans with a straight flow in and out for a few more HP. a good source is how to built chevy sm blks by hot rod mag I found it in a book store in the US about 2 yrs ago it is full of good set ups test runs and advice from Smokey and the Ling"master"
 
T

tacoed

Guest
Hey Ga Bulldog!!

A good way to seal that leak is to get the copper gaskets dubble one up use a drimmel tool and cut the top & bottom flange then bolt them back down I did this on an old CJ-5 w/a 304 that I once had and it worked GREAT..
 
R

rpounds

Guest
Tacoed . . . Great quote!! Reminds me of my ex . . .
 
S

sscam69

Guest
Suggestion

I went with 1 5/8" primarys and 3" collecter to a 2.5" system.

Get the coated headers, I used header wrap to keep the gases hot to improve flow but they are turning to be a pain. The get wet and steam up, eventually will rust pipes, and when I changed rockers I spilt oil on them and when I drove around it looked like I blew up my engine. That was embarrasing.

If you have the stock setup don't worry about the primary tube. Leave it at 1 5/8

Didn't you change the cam?

If it has a lot of overlap you might want to keep the primary tube bigger than the exhaust port on the heads. As the engine sucks that exhaust back in that difference in diameter prevents some the the spent gases from coming back in giving you some power on the lower end.

sscam69

p.s. Did you change the cam with the engine still in the car? I recall you posted something about it. If you did how difficult was it?
 
Joined
Nov 4, 2000
Messages
946
Location
Scottsville, Kentucky
Corvette
08 Jetstream Blue Z51 coupe
sscam69, I too wraped my headers with some insulation from DEI. I also painted them with the high temp paint that came with the kit. I have not seen any indication of steaming or water being absorbed as you mentioned. The high temp silicone paint rated at 1500 degrees, is available at any parts store or Walmart.
 
R

rpounds

Guest
To answer an earlier question, yes I changed the cam with the engine in the car. It is not particularly difficult to do. The radiator has to come out in order to provide forward clearance. But other than that, it's not a difficult job. I guess it took me about 12-14 hours total. I burned up at least 3 of those hours with the radiator. That thing is a PITA. It has to come out at a funky angle and pretty much takes two people . . . good thing my wife was home. But, once the hood and radiator are gone, it's just a matter of R&Ring the other pieces. Don't forget to degree the cam.

The reason for the original post is that I am getting ready to replace my heads. I want to get rid of the shorty headers while I'm at it (1 5/8" tubes) and am considering going to something else.
 
S

sscam69

Guest
The reason I ask is because the cam that was put in my newly rebuilt engine wasn't exactly what I asked for.

"If you want something done right, do it yourself"

I was thinking of swapping out the cam for a comp cams XE285H. Or something like that number, anyways I ran that cam profile on the desktop dyno software and got about 340hp and 360ftlb which is what I am looking for. NO let me correct myself, what it should of had in the first place.

I actually inputed the settings for an engine that Chevy Hi-Performance put together and dynoed and it was only off about 10hp and 10ftlbs. Something like that, the point is that it was very close!

What I was afraid of was that I was going to have to pull out the engine again and do it that way but when I read your post a big light bulb went off. If I do it it will be in the beginning of summer.

My questions for you are:

What special tools am I going to need?
What should I watch out for in particular?
How do you set the cam right? I mean what do you use as a reference to tell is on right?
Do you have to turn the crank to get the #1 piston at TDC?

I have some gear head friends that are willing to help me out and I have saved some pennies so that I can afford it. I am also assuming that I have to take off all the top portion? Gotta remove those lifters somehow.

any advice would be greatly appreciated.

sscam69
 
R

rpounds

Guest
SScam,

You will have to pull the intake manifold, water pump, valve covers, harmonic damper . . . anything that prevents you from removing the lifters and timing chain cover. Remove the fuel pump. There is a lobe on the front end of the camshaft that actuates the fuel pump. On SBCs, there is an actuator rod that runs from the cam to the fuel pump. This rod needs to be pulled out far enough for the cam bearing journals to clear. I prefer to remove the fuel pump adaptor plate so that I can completely remove this actuator rod. There is a 3/8-16 UNC tapped hole on the front of the block that intersects the fuel pump actuator rod bore. When reassembling, you can shove the actuator rod back up in it's bore and hold it in place by screwing a 3/8-16 UNC bolt into this threaded hole. Do not tighten this bolt! It only needs to be finger tight to hold the rod in place to facilitate fuel pump installation.

Make sure you use new lifters with the new cam. Even if your current lifters have only been run a few miles, don't take the chance of ruining your new camshaft by re-using your old lifters. Always, always use new lifters with a new cam. When removing the old cam, mark the old lifters as to position in the engine so that if you ever want to go back to the original cam you will know which lifters match up with which lobe. Use plenty of cam assembly lube on the bottom of the lifters and on each individual lobe (including the fuel pump lobe). Lubricate the lifter bodies and cam bearing journals with motor oil prior to assembly. Also (everyone seems to forget to mention this), lubricate the distributor gear drive.

When removing the old cam and installing the new, be very, very careful of the cam bearings. The edges of the lobes are sharp and can destroy a bearing during installation. A lot of people use a 'cam installation tool' which is really nothing more than a handle that bolts on to the front of the camshaft with the timing sprocket tapped holes. I don't use this tool . . . if you are very careful, you don't really need it. However, it does make the install a little easier to do without banging the lobes against the bearings.

As far as tools are concerned, I would recommend using a puller specifically designed for removing/installing harmonic dampers. Most any three armed puller can be made to work for pulling the damper off . . . but you really need to use something other than a big hammer to put it back on . . . that's a bubba trick that I would surely not recommend.

As far as degreeing the camshaft, you will need a degree wheel and a couple of other things. Take a look at the Crane Cams website. They have a detailed proceedure for checking cam degree. If you have some gear head buddies, buy a case o' beer and invite 'em over to help. Just make sure none of them are named Bubba . . .

Hmmm . . . hope I didn't forget something. If I did, I'm sure someone will chime in here.

Ron
 
R

rpounds

Guest
Oops . . . I knew that I would forget something . . . the oil pan needs to be dropped in order to get the lower timing cover rubber gasket in place. I know there are some tricks that people talk about the get the cover back on without dropping the pan. However, on a C3, it's not that bad of a job to just drop the pan. Maybe someone will post with and easier solution.

Ron
 

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