Hi Convincor, Fordman, Eric, Fitzwell, and 70_F100, thanks very much for replying!
Before I respond to each of your great replies, I have an update. I mailed some of the photos to Steve at Proformance Unlimited and gave him a call. Here are the questions I asked and the
PARAPHRASED responses I heard:
- During the live run video, Doug mentioned that he couldn't get the exhaust manifolds to seal. Is that because of the bad surfaces on the heads?
Steve at Proformance Unlimited wrote:
No, that's because all of our live run manifolds are warped. When we remove them while they're still hot, they warp, and there's no way around that. So the exhaust manifolds leak during a lot of their live runs.
- What's the deal with the bad surfaces?
Steve at Proformance Unlimited wrote:
The corrosion was caused by a previous gasket installed on the engine. Some gaskets have metal on them that actually embeds itself in the surface of the head around the exhaust ports. That's what this rough surface is caused by; it's not caused by rust.
- Why didn't you put new surfaces on these heads?
Steve at Proformance Unlimited wrote:
They don't cut a new surface on these heads because they don't have a machine that will cut on that angle. So they use some kind of grinder (I didn't hear exactly what type he said) with a scotch brite pad to smooth them out.
- What type of gasket do you recommend, and how can I keep these headers from leaking?
Steve at Proformance Unlimited wrote:
Use any (M)ulti (L)ayer (S)eal gasket. Those have metal surfaces that crush when you install them and fill in the defects. If I don't want to use one of those gaskets, use any gasket type I want and include a bead of black, high temperature RTV silicone around each exhaust port. That stuff won't burn out. Some header manufacturers actually recommend using the RTV instead of using any gasket at all.
- What should I do if I put the whole thing together and it still leaks?
Steve at Proformance Unlimited wrote:
It won't leak--I shouldn't have any problems.
Great, thanks very much! I like the looks of those RemFlex gaskets and might go with those. It's good to know that other heads out there look worse and still function!
fordman wrote:on stock heads and manifolds the surfaces should be planned flat when rebuilding an engine. to make sure the manifold and head fit together flat when installed. supposedly. from the factory no gasket was used at all. on the exhaust to head surface. if yo uhave a warped surface on either it could lead to a cracked manifold sooner or later. this warp can often be told by gaskets that leak when installed. even though the gaskets are sometimes put on there to hope any warps will get taken up by the gasket material. im not sure i explained that correctly or clearly i should say.
I see. Well, hopefully what Steve said about not having the equipment to cut a new surface on those heads makes sense. Although I didn't directly hear him say this, I thought his tone of voice indicated that the equipment either didn't exist, or was very rare, that could cut a new surface on those heads.
71PA_Highboy wrote:For the price you paid, I am shocked that they didn't machine the exhaust sides of the heads. That is a VERY common issue on these engines, and resurfacing the exhaust is almost mandatory.
You seem to have a decent relationship with that company... you don't you ask them why they didn't resurface the exhaust side?
Good luck!
Eric
Yeah Eric I see what you mean! Do you think their reason for not putting a new surface on those heads makes sense?
fitzwell wrote:Victor Nitroseal header gaskets. Run a bead of ultra copper around the ports (both sides).& let set for about 15-30 min to "skin over" Assemble & keep an eye on the bolts, re-tightening as needed for the first couple hundred miled or so.
Okay, thanks for the recommendation! I'll look at both the RemFlex and Victor Nitroseal gaskets. I did ask Steve at Proformance Unlimited about these Nitroseal gaskets and he said that they're good!
70_F100 wrote:Those heads should have been resurfaced on the exhaust side. No excuse for that poor workmanship on a HiPo engine.
I'm inclined to agree, yet I'm not sure if Steve's explanation makes sense or not. Is it probable that a big engine builder wouldn't have the equipment necessary to cut those surfaces? It's not that I think Steve wasn't telling the truth, I just don't fully "get it."
Thanks again for the superb replies!
Robroy