View Full Version : Votec Heads with Square Exhaust Port??


RockinZ
01-21-2010, 06:46:33 PM
Vortec heads are not square bore stock are they?
Now I know why I have exhaust leaks at the exhaust ports. Pretty sure my headers are oval port.

So am I screwed or what? Have a look...

http://i397.photobucket.com/albums/pp56/RockinZ/EnginePhotosNov30010.jpg

REARSPROCKET
01-21-2010, 07:09:41 PM
I bought a set about five years ago for my boat and the ones I recieved have the sideways D exhaust ports, but I have seen pics of new Vortecs that dont have the D exhaust ports, so I dont know if it was a running design change or what. I know the Bowtie Vortecs heads don't have the D exhaust ports. Maybe you should ask Dirt in the Vortec sticky.:bowtie:

sooner
01-21-2010, 07:36:07 PM
looks to me like someone just matched them to the factory square gaskets. If thats the case I think you will have a tough time making an 1-5/8 primary header seal up.

RockinZ
01-21-2010, 08:57:04 PM
looks to me like someone just matched them to the factory square gaskets. If thats the case I think you will have a tough time making an 1-5/8 primary header seal up.

Yeah that's what it looks like. So what can I do? buy 1-3/4 headers?

AJ_72
01-22-2010, 02:35:29 AM
Ouch. :eek:

That's gotta hurt the old pocket book.

Yet another fine example of why one shouldn't gasket match. Port matching is the preferred method.

enjoideviantly
01-22-2010, 03:46:54 AM
yeah stock vortecs are not square.

If it were me in your situation, I would check into new heads vs new headers?

sooner
01-22-2010, 05:35:37 AM
Yeah that's what it looks like. So what can I do? buy 1-3/4 headers?

While there may be options other than buying bigger headers, I can tell you that I tried to save a few bucks when I built my motor and use the factory square port MLS manifold gaskets on my 1-5/8 headers and it sounded like a paper sack stuck in a fan.

Dirt Reynolds
01-22-2010, 07:52:41 AM
This is the stock L-31 Vortec exhaust port:

http://img85.imageshack.us/img85/7396/vortec5.jpg

Damon
01-22-2010, 07:52:52 AM
Factory Vortecs have a roundish-square shape. But that's clearly had work done to it- not the factory casting finish inside. Looks like it's been opened up and fully squared off.

RockinZ
01-22-2010, 08:24:01 AM
What are my options other than stepping up header size?

There seem to be very few square port headers.

dwright406
01-22-2010, 09:03:35 AM
I had a set of heads that someone ported out square years ago, I never could get headers to seal on them.

It's something I don't understand, I mean the valve is round, the header tube is round, why on earth would you want to make the exhaust port square?
I understand "D" shaped ports, but square makes no sense to me.

z28rod
01-22-2010, 10:40:45 AM
why on earth would you want to make the exhaust port square?
because they didnt know what they were doing ?

Damon
01-22-2010, 11:48:37 AM
Only thing I can think of is to grind the header flange down flat so that the whole thing presses against the gasket, not just the raised bead around the pipe where it sticks through and attaches to the flange.

BondoSpecial
01-22-2010, 01:24:20 PM
LOL what a mess. The OLD version of the 1 3/4 SBC headers that you find used for 50 bucks, came with square ports, 65104 part number or something like that. I had some, I can post a pic. But I wonder how much flow was helped or hurt by screwing the ports up like that

RockinZ
01-22-2010, 08:13:05 PM
WHy are so many gaskets square? Is this to fit manifolds? I just don't get it. Are some stock cars limited to manifolds? Maybe this is why it was done?

I figure right now I have turbulence right there, even with a good seal. The only way fix that is go large tube headers.

Damon
01-22-2010, 08:35:51 PM
Yes, gaskets are square to fit the manifolds. Stock manifolds use the entire flange to seal the gasket surface, too. Similar to how I recommended you modify your header flanges to seal up. Agreed, there would probably be a mismatch at that point- you'd have to do a tracing using the bolt holes as a reference to be sure, but I was just offering that up as an inexpensive way to seal up what you've already got.

RockinZ
01-22-2010, 08:41:45 PM
Thanks Damon, it's a good idea. to at least get them to seal correctly.

1980RS
01-24-2010, 05:36:43 PM
I was always told by one head ported to flatten and widen the port floor but if the port floor is higher than the gasket or the header then leave it as it will cause turbulance and scavenge the port better, He also said to round the port at the top of the exhaust port thus making it a D port. Must work.

RockinZ
01-24-2010, 06:10:00 PM
Hedman makes square port header flanges, but only in 1 3/4 tube. If I have to go up to 1 3/4, I might be able to use std headers and get that anti-reversion going. Right now I am sure I am anti-anti-reversion.

I will measure everything when things warm up in march.

I have to tear down the engine this spring due to noisy lifters and metal in the oil.

Now I will have to change my headers as well. :mad:

Bikefixr
01-24-2010, 10:26:03 PM
Use gaskets made of dead-soft copper or aluminum. They are better able to fill in voids in coverage. I don't use anything else now.

RockinZ
03-22-2010, 08:27:33 PM
Well I got the heads off. We measure the ports they ar slightly smaller than the 1405 felpro gasket that goes with the 65104 header. I guess I don't have a choice. I need to replce those headers anyhow.

NYH1
03-23-2010, 01:17:10 AM
Now I'm confused.

I have THESE (http://www.summitracing.com/parts/SUM-151124/) Summit Vortec heads. They have square exhaust ports. I went to Summits web site. I look for SBC assembled cast iron heads with square ports. 78 heads showed up from Dart, World Products, RHS, GMPP, Summit and Patriot Performance. The heads that showed up are the more popular heads like S/R Torquer, Iron Eagle ect. HERE (http://www.summitracing.com/search/Make/CHEVROLET/Engine-Size/5-7L-350/Engine-Family/Chevy-small-block-Gen-I/Department/Engines-Components/Section/Cylinder-Heads/Part-Type/Cylinder-Heads/Cylinder-Head-Material/Cast-iron/Cylinder-Head-Style/Assembled/Exhaust-Port-Shape/Square/?Ns=Price%7cAsc) are the heads that showed up.

Are there more then one type of square port heads? Some of the heads that showed up show the exhaust side of the heads. You'll see they definitely have square exhaust ports. Heads like the S/R Torquer, Sportsman II, Iron Eagle 165, 180, 200 ect.

Dirt Reynolds
03-23-2010, 04:43:23 AM
Hedman makes square port header flanges, but only in 1 3/4 tube. If I have to go up to 1 3/4, I might be able to use std headers and get that anti-reversion going. Right now I am sure I am anti-anti-reversion.

I will measure everything when things warm up in march.

I have to tear down the engine this spring due to noisy lifters and metal in the oil.

Now I will have to change my headers as well. :mad:

The Hedman 1 3/4" coated long tubes are what I had on my old '77 Z28 with the 413/Vortec combo. They fit superb in every way, excellent ground clearance and they tucked up nicely to the floor pan. Later on I also had Bow Tie aluminum angle-plug heads, and they bolted up fine to those as well. Very good plug access. Best set of headers I've ever had on any of the three 2nd gen Z28's I've owned over the years.

RockinZ
03-23-2010, 08:12:31 AM
Problem is there are no 1 5/8 square port, long tube headers. Why???

RockinZ
03-23-2010, 08:22:14 AM
Dirt, do you have the part number for those headers?

MyBoTy
03-23-2010, 08:24:21 AM
Header pipe match isn't nearly as important as the intake ports, remember you have scavenging going on. I can't imagine a 383 with Vortecs needing a bigger header primary. Going to that big of a header will hurt more than the mismatch you have now, IMHO.

NYH1
03-23-2010, 02:08:29 PM
THIS LINK (http://www.summitracing.com/search/Make/CHEVROLET/Engine-Size/5-7L-350/Engine-Family/Chevy-small-block-Gen-I/Department/Engines-Components/Section/Cylinder-Heads/Part-Type/Cylinder-Heads/Cylinder-Head-Material/Cast-iron/Cylinder-Head-Style/Assembled/Exhaust-Port-Shape/Square/?Ns=Price%7cAsc) I posted above shows some of the most popular heads used today having square exhaust ports. S/R Torquers, Sportsman II, Iron Eagle 165, 180 and up, RHS Vortec type and regular types heads, Patriots heads. 78 different heads showed up. Most guys that use the above mentioned heads use 1 5/8" headers without any issues. 1 5/8" headers are probably the most popular size headers for SBC.

Like I asked, are there different types of square exhaust port heads?? Or am I missing something??

Damon
03-23-2010, 07:54:25 PM
The heads that are being talked about in this thread are a special case- they have had the exhaust ports hogged out and squared off at the same time, causing issues with "off the shelf" headers. Out of the box heads would almost never have this issue with typical 1-5/8" headers.

RockinZ
03-23-2010, 08:52:47 PM
It looks like they were gasket matched to the Felpro 1404 vortec header gasket. We measured a 1405 and it was slightly larger.

tom3
03-23-2010, 11:05:15 PM
Wonder if someone worked these ports to work with cast iron manifolds for some reason?

NYH1
03-23-2010, 11:15:53 PM
The heads that are being talked about in this thread are a special case- they have had the exhaust ports hogged out and squared off at the same time, causing issues with "off the shelf" headers. Out of the box heads would almost never have this issue with typical 1-5/8" headers.
Thank you! :)

Dirt Reynolds
03-24-2010, 04:53:28 AM
Dirt, do you have the part number for those headers?

Not right off the top of my head, sorry. They should be on Hedmans site though.

RockinZ
03-24-2010, 06:36:50 AM
Do they have rules in circle track racing that don't allow headers? The heads were meant for a race car.

petes67bird
08-07-2011, 11:54:04 PM
I know this thread is old but I am in the same predicament. I bought the Year One Power Crate 350 and have Vortec heads on there. I have a square port 1 5/8 header but I have a massive leak on my passenger header between the center ports, I think the header is warped as the driver side is fine and the header is old. What type of header should I buy for my 1980 Camaro. The only thing I see are oval port headers for the year of my car. Any help would be great.

vlmohr
08-08-2011, 04:10:27 PM
I know this thread is old but I am in the same predicament. I bought the Year One Power Crate 350 and have Vortec heads on there. I have a square port 1 5/8 header but I have a massive leak on my passenger header between the center ports, I think the header is warped as the driver side is fine and the header is old. What type of header should I buy for my 1980 Camaro. The only thing I see are oval port headers for the year of my car. Any help would be great.

Try the real thick soft aluminum gaskets. Took care of it on my son's malibu and on my z28. Both leaking in that spot.

petes67bird
08-08-2011, 06:27:41 PM
Try the real thick soft aluminum gaskets. Took care of it on my son's malibu and on my z28. Both leaking in that spot.
Which ones are you speaking of? And should I buy the square or round ones?