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Couldn't you port your own exhaust manifolds?

Old 02-27-2003, 11:37 PM
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Default Couldn't you port your own exhaust manifolds?

I used to cruise a BMW board when I had a '77 530, and they talked about porting your own exhaust manifolds simply by taking a Dremel to them and "hogging" them out a little. They showed before and after pics and it didn't seem that hard. Isn't that about all there is to it? I was going to do it to my Bimmer but I sold it.
Would it be that hard to do it yourself to our 3800 manifolds?
Old 02-28-2003, 01:12 AM
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You can do anything yourself.
If it'* a risk you are willing to take and are willing to experiment with results.
The vendors on this group have done a lot of mods to their cars and others.
We should benefit from their experience.
Their prices are very reasonable.
Old 02-28-2003, 02:00 AM
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Personally as great as the regular guy with a dremel may be there are guys who have many moons of experience and its these professional engine builders with proper flow equipment that make the difference between a bigger hole and a better flow. Read the info on heads and you will see a bigger hole is not always what it is about. Ceramic coating is also something most of us cannot do in our back yard. The majority of the companies I use have at least 20 years experience producing the products they make. I figure it’* just as hard to use a pro as it is to do it yourself or hire a backyard wanabe.

The only variable in most automotive product is the builder and the quality along with that option. In most cases the more expensive product is based on better quality and experienced builders. I have several engine builders I work with but the most expensive are the ones who blueprint Rolls Royce engines or bush series engines. Then come smaller track engine builders and then the small shop and then the guy next door who has it figured out. Personally I prefer to hire the pro’* to do the best job I can get.


Sorry I could go on forever.

Ty
Old 02-28-2003, 03:14 AM
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I`ll agree with Speedguy...it may sound easy,,but if yuo never have done it .get a set of junk manifolds try it on them.or just get the pro`* to do it which ever way you want to is up to you ......i do most of my own work ( been doing it for 30 yrs )
Old 02-28-2003, 11:11 AM
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I understand all those reasons you've all mentioned, but it just doesn't seem that hard of a thing to do. The effect you're going for is to hog them out slightly bigger than the exhaust port so that you get a scavenging effect, correct?
I guess one drawback is that the 3800 manifolds don't look like they have a lot of extra material. The BMW manifolds were thick, like the old Chevy V8'*. Just from eyeballing the 3800 manifolds, it looks like they are pretty thin to begin with.
I don't know if I'll ever try it, it just seems like it'* within the realm of 'do it yourself'.
Old 02-28-2003, 11:28 AM
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The 3800 manifolds are not that thick. About the only thing the is done with the is cleaning up the interior weld lines. I went through 4 sets trying to get mine right... I had the time. I also added some support to the outside of the manifolds for added strength. I have not had them dipped yet, but I am chaging out the motor this summer and the new mill will get coated manifolds.
Old 02-28-2003, 12:26 PM
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Well I agree with messing around because I always do mess with my own car but I have made many expensive mistakes and because I don’t want it coming back to me I don’t like to suggest options that may cause problems. ..But personally I would just polish the inside and call it done. What I sell is more for the person who just wants to buy the option and have someone else’* head on the block if something is wrong. Personally I wouldn’t even bother coating them but a set of series 1 coated pipes will look very nice. I do series 1 and series 2 exhaust manifolds. And and most important is even my polish job will not be as good as a pro. No mater what way you slice it a pro is always going to build a better product.

Ty
Old 02-28-2003, 12:40 PM
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http://www.bonnevilleattitude.com/fo...opic.php?t=566

I know there have been some arguments about intakes and other things and some ideas about two different forums but this is not why I am posting this link it is because I don’t want to post twice. I do value having two forums, more than one opinion. I also prefer the tech style format that BA brings when I need an answer, but in the end it’* all good.

Anyway take a look and then you will get an idea of the price I will offer on my site and the deal I give to BA forum members through there store.

Ty
Old 02-28-2003, 01:20 PM
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Thanks for the great advice and links.
Let me be sure I really understand what you mean by exhaust porting. What I think it means is to make the inside diameter of the exhaust manifold a little bigger than the diameter of the exhaust port in the head. My understanding of the benefit of doing this is so that the exhaust pulses don't get sucked back into the head, but instead are scavenged better by the manifold. Is that it?
Old 02-28-2003, 01:35 PM
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Originally Posted by brminder
Thanks for the great advice and links.
Let me be sure I really understand what you mean by exhaust porting. What I think it means is to make the inside diameter of the exhaust manifold a little bigger than the diameter of the exhaust port in the head. My understanding of the benefit of doing this is so that the exhaust pulses don't get sucked back into the head, but instead are scavenged better by the manifold. Is that it?
Yes and i am getting a deal for heads and soon i will have a rocker kit for the series1.

Ty
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