Preping / Porting Ex. Manifolds

[James Thomas]

When you guys are preping the stock manifolds is there anything other than matching the ports to gaskets as a template and the turbo flange to the turbo for my P.T.E. 67 that should be done? I ran across this pic and was woundering if cutting down / removing the divider is worth it or even recomended? Anyone wanna post some pic's of your ported manifolds to compare?



As always, thanks!

________________
James

 

[It's just a six]

Re: Preping / Porting Ex. Manifolds

Divider looks pretty thin.,,,,,Might crack now??
I would not remove it.
You can do porting on various areas other than the turbo flange area.
Problem is, it is hard to reach deep inside.
Need a long porting bit,like a 6" or so.
Need to blend in any sharp turns before the turbo & other areas.

 

[James Thomas]

Re: Preping / Porting Ex. Manifolds

Agreed, like I said I just ran across this pic. I saw a thing saying that cutting down the divider was a good thing? Ever hear of this? I'm not flow dynamics engineer but the P.T.E. turbine housings don't have a matching divider so I'm woundering what's the use? Any on have a clue?

___________
James

 

[Wikid 1]

Re: Preping / Porting Ex. Manifolds

I was looking at my manifolds the other day, and I'd defintaly say LEAVE IT there, and much thicker than in that pic. reason being: look at the angle that it takes just below the flange back into the manifold, not the crossover pipe, it's pretty sharp, and if you remove it i'd be lead to believe you'd force all the air to the oppisite side, leaving a large dead spot in the manifold before the exhaust housing. I say it's not hurting any thing, and making it that thin would only risk heating it to the point of meltdown, sending molten steel through your turbine, and at 150k + rpms as you could imagine it wouldn't be a good thing.

 

[10secTy]

Re: Preping / Porting Ex. Manifolds

Go here to see pics of ported manifolds.

Nolan

 

[James Thomas]

Re: Preping / Porting Ex. Manifolds

Go here to see pics of ported manifolds.

Nolan

So it's ok / good to thin that runner out like those pics show but not cut it down or remove it all together? What's the real up side to thing it down that much? Just courious.

_________
James

 

[10secTy]

Re: Preping / Porting Ex. Manifolds

Just bascially trying to make the opening as large as possible. Also had done some reading on areo and that it helps gas flows if you take it to a knife edge. Either way they seam to work ok making 740hp.

Nolan

 

[James Thomas]

Re: Preping / Porting Ex. Manifolds

Thanks Nolan, much appericated, BTW I got my care package from Craig with all the goodies we need to start tuning & burning . It was slow in the shop this afternoon so I had some time with no one bothering me and I thought I would do the lay out work ahead of time and be ready for some quaility time with the grinder on Saturday :tup: . I bolted the manifolds to the heads with the valves out to get a look at the port match up and this is what I found on ALL SIX EXHAUST PORTS! Not just one or two but all of them :tdown: .


Port Mis-match


Scribe line

Not I'm not shocked being mass produced parts but all six of them and it a full 1/8 - 3/16 mis-match on the top and one side of the port. The other side and floor of the port, the manifold opening is larger so no problem there. But all six ports? And look how close it is to the damned bolt hole after I scribed it from the inside! I got to thinking that we use the Fep-Pro Ms90746 gasket as a template to match L-35's a lot and didn't have that kind of mis-match (on headers anyway) and these manifolds almost match the gasket with no grinding at all so I bolted these manifolds up to several L-35's here in the shop and they are real damn close. For sure not an 1/8 or more off on two sides.

I don't know if it's these manifolds, this set of Vortec heads or the fact that the Vortec's just don't match the turbo manifolds very well but if all of the stock exhaust manifold / Vortec combo's are like this, just matching the the exhaust port and the manifold port to the gasket ain't gonna cut it because the port alignment it's self is way off (at least on this set anyway)! On the two that get so close to the bolt hole, all that can be done is grind it at an angle and try to "funnel" the exhaust flow as best as I can.

Word to the wise if doing the Vortec swap, bolt the mani's to the heads on the bench before you assemble the heads and look through the exhaust port with an inspection light and see if yours are like mine. I guess just because they both match the gasket doesn't mean they match each other and 3/16 will hurt flow!

_______________
James

 

[autoaddictions]

Re: Preping / Porting Ex. Manifolds

I just had my stock manifolds extrude honed myself worked pretty good. What the hell are you guys using for a gasket between turbo hot side and manifold flange???. I cant find a gasket Copper, metal or anything !!! Any ideas cant see permatex working here.

 

[Windedv6]

Re: Preping / Porting Ex. Manifolds

I just had my stock manifolds extrude honed myself worked pretty good. What the hell are you guys using for a gasket between turbo hot side and manifold flange???. I cant find a gasket Copper, metal or anything !!! Any ideas cant see permatex working here.

Red Hi-temp permatex. I burnt out or blew many exhaust gaskets (manifold and turbo) so I went to no gaskets and the permatex several years ago. No problems since. Have run 30# of boost and 1,600* egt's with no regrets.

John

 

[Don W.]

Re: Preping / Porting Ex. Manifolds

Here's my :2cents: on this. Some turbo's have a divided turbine housing. 1/2 the housing hits the first 1/2 of the turbine, the second the second 1/2. As the exhaust pluses come through it's sort-of like kicking an already running horse. Without that kind of housing on our turbos the divider means little. I wonder if GM had plans for a divided housing turbo back in the beginning? Or, as has been mentioned, it's a structural thing?

 

[autoaddictions]

Re: Preping / Porting Ex. Manifolds

Red Hi-temp permatex. I burnt out or blew many exhaust gaskets (manifold and turbo) so I went to no gaskets and the permatex several years ago. No problems since. Have run 30# of boost and 1,600* egt's with no regrets.

John

Unreal that shits only rated to 900 degrees!! ill give it a go though.

 

[canadian]

Re: Preping / Porting Ex. Manifolds

Those particular manifolds were running on Hunter H's Typhoon for a while, now they're in a box waiting to be put on. He ported the manifold inlets too.

 

[James Thomas]

Re: Preping / Porting Ex. Manifolds

Those particular manifolds were running on Hunter H's Typhoon for a while, now they're in a box waiting to be put on. He ported the manifold inlets too.

Which manifolds are you refering too?

____________
James

 

[berzerker]

Re: Preping / Porting Ex. Manifolds

on the gasket between the turbo and the manifold. u can get the metal gasket at about any heavy duty truck dealership , mitsubishi-mack, international,, are your best choices to locate that style.

 

[canadian]

Re: Preping / Porting Ex. Manifolds

Which manifolds are you refering too?

____________
James

The ones in that picture. They're sitting in my garage right now. That picture was from when I was trying to sell them on eBay with the crossover and external wastegate. Now they just wait to be put to use.

 

[James Thomas]

Re: Preping / Porting Ex. Manifolds

My bad, I thought you were talking about the ones I posted with the scribe lines cause those are on the way to be AFM (Extrude Hone) processed by Engineered Finishing Corp. right now. Can't wait to get them back!

_________________
James

 

[TDSRacing]

Re: Preping / Porting Ex. Manifolds

What gaskets to use between motor and manifold. What about ceramic coatings?

 

[Black Knight]

Re: Preping / Porting Ex. Manifolds

What gaskets to use between motor and manifold. What about ceramic coatings?

None high temp RVT and yes do ceramic coating.