Header gasket vs. no gasket [Archive]

boat737

11-07-2016, 02:35 PM

For months, I've been reading the pros and cons of using a header gasket or not. So as not to hijack the other threads, my question is when does one use a header gasket, and when not to use one. There must be a time to use them, and a time not to.

I have just installed my engine so I'm getting close to having to make that decision. I have a Dart 427w, 750cfm carburetor, with Edelbrock Victor Jr. Aluminum heads, standard 4-into-4 ceramic coated headers. My usage will be exclusively street, no track. The engine builder said to use the gaskets, but a lot on the forum opt not to, and use silicone (ultra copper, etc) instead.

Just when should the exhaust gaskets be used, or not used?

Avalanche325

11-07-2016, 04:57 PM

I had always been an old school use gaskets guy. Both of mine blew out pretty quickly, just a few hundred miles. After reading on the forum, I decided to give the ultra copper only a skeptical try. I am over 9000 miles street and many rev limiter banging autocross runs later, and I have never had an issue just using RTV. I won't be going back to gaskets.

I never tried any of the fancier higher priced gaskets. But I won't bother now.

CraigS

11-08-2016, 07:17 AM

If you go for the copper rtv you need to assure that the header flanges are flat. I did that w/ a big flat file. Ran it along the length, then on a diagonal, then the opposite diagonal. That let's you see the low spots as they won't change appearance when you switch directions. I have used the silicone for a long time on a lot of engines. I think the advantage is this. When you blow out a gasket it is usually 1/4 to 3/8 inch by gasket thickness (.050-.070 inch) chunk missing. That's a huge leak. If some of the silicone blows out, it's nearly zero thickness so only a tiny leak.

BEAR-AvHistory

11-08-2016, 08:42 AM

Have the FFR supplied gaskets in. 21 months @ 5000 miles without a blow out. That said have been using RTV for years on headers with great results. For whatever reason (old farts moment) did not think about it when assembling that section of the car.

Cyclotic

11-08-2016, 09:12 AM

I have a similar setup - 427W, Victor Jr heads, carbureted, standard 4 into 4 headers. I'm using Felpro gaskets. No problems so far, 2000 miles.

boat737

11-13-2016, 08:16 PM

Well, got the engine in, and been working on the wires, hoses, linkages, fluids, etc. Getting close to finishing it up, and that will be putting on the exhaust. I'm still in a quandary over whether or not to use the header gasket. Since the engine builder recommended it, I guess that's what I will do. Gasket it is. Fingers crossed.

Bad Moose

11-13-2016, 09:13 PM

CraigS

11-14-2016, 07:23 AM

You will probably be fine. The last time I removed gaskets was after one blew and I didn't have a new one on hand so, copper rtv it was. But I also noticed there is a design problem w/ my 2005 headers vs the exhaust ports of my Edel Performer RPM heads. The header flange is X inches wide and the gasket is about 1/4 in less than X. But that 1/4 in is not removed equally top and bottom. It's been quite a few years now so I don't remember for sure if it's the top or bottom that has the problem, but the result of all the above is that there is only about 1/8 in of gasket in use across the top (I think) of the port. So that is where it blows out.

AC Bill

11-14-2016, 02:05 PM

For months, I've been reading the pros and cons of using a header gasket or not. So as not to hijack the other threads, my question is when does one use a header gasket, and when not to use one. There must be a time to use them, and a time not to.

Should be obvious by now, there is not one "particular" reason, to use one or the other. It's really more of a personal choice.

I would heed the advice to use Remflex gaskets, if you go that route, and use suitable locking bolts regardless of which route you choose.

boat737

11-14-2016, 06:35 PM

Look up Remflex. Several guys have used them and recommend them. I did this a while back after I blew my regular gaskets out. Searched and bit the bullet on these. Put them in according to instructions provided. Have had no problems since.

http://catalog.remflex.com/

Thanks all. Looked up the RemFlex, and from my novice viewpoint and understanding, they look good. I'll have to check, but I think I got FelPro's in the garage at the moment, but $33 or $40 is cheap insurance to not have to replace them right away. RemFlex's are in the lead, but I'm going to call them up to make sure there aren't any issues with the Edelbrock Victor Jr. aluminum heads. Plus, it looks like there are 5 or 6 different styles of 351w type ports and bolt hole configurations. Who knew?

Next, since it's my thread, and since AC Bill brought it up, let talk locking bolts. I know they are out there, but know nothing about them. I guess my first question would be, are they safe to be using in aluminum threads/heads? (I don't want to be buggering up the threads). I think there are different locking methods, any of them obviously superior to the other? My engine builder recommended the 242 (blue) Loctite, but I'm a bit hesitant with aluminum heads.

Thanks again. Let's have at it.

Bad Moose

11-14-2016, 09:09 PM

I did not use them with the Remflex. Several people stated because of the squish and the way they work you did not need to. I did put hi temp rtv on the threads though. I too researched the locking bolts and decided that if these loosened up I would go for them. If not I just saved the extra cost and will put that to the oil filter housing......

Just my thoughts.

edwardb

11-15-2016, 02:24 AM

I've had great luck with Remflex gaskets on all three of my builds, so don't hesitate to recommend them. Admittedly, haven't tried the no gasket / RTV approach. Enough people recommend it I'm sure it would be OK if the surfaces match up well.

For the locking bolts, there are several kinds. Stage8 and Percy's Vibe Lock are two well known ones, and I've used both. They won't hurt your aluminum heads. The locking mechanism is separate from the threads themselves. Mr. Gasket also sells bolts that have a serrated head and locking material on the threads. I haven't used them. Sort of mixed reviews on Summit Racing.

For my current build, I couldn't find any locking bolts the right length for the Coyote and GP Headers. So I'm using bolts with copper RTV on the threads. Blue Loctite won't hurt your aluminum heads, but I don't think it's intended for the heat it would see in that area.

Bob Cowan

11-15-2016, 03:31 AM

boat737

11-18-2016, 12:03 AM

Here's the problem. You're trying to match up the Aftermarket heads, and aftermarket exhaust flanges. Unfortunately, they don't match up very well. And that's why they fail. If you look at this FFR header, and this supplied gasket, you can see that it just doesn't fit well. This is a failure waiting to happen. It's not a problem with the gasket material, it's just a poor fit. This is why they fail.

Update.

I am still prepping and trying to get to that "first start". But the forces are against me.

I think all the fretting over "gasket or no gasket" is for the time being a moot point. I got bigger problems. I pulled out the exhaust headers today to start laying out my assembly. I just happen to notice that the exhaust ports on the heads are square, and the ports on the headers are rectangle. They are not even close. So I'm dead in the water. Again.

I've been out of town for the last week, and believe it or not, I did not see Bob's post above until just now when I went to update this thread. Had I slapped the headers on, especially with the gaskets, they wouldn't have lasted 200 miles I bet.

So to again hijack my own thread, how, where, who, what headers do I get? I don't know how this happened, and I really don't know how to fix it. I'm sure these nice new headers are useless, so I hope somebody can get me pointed in the right direction again. Thanks.

6107861079

Bob Cowan

11-18-2016, 01:04 AM

This is not a problem. These are the same headers everyone uses. Just put some silicone on the header flanges and bolt them on. It will work.

boat737

11-18-2016, 10:30 AM

This is not a problem. These are the same headers everyone uses. Just put some silicone on the header flanges and bolt them on. It will work.

Really? Man, that's hard to believe. My engineer part of me says there's no way in "H-E-Double Hockey Sticks" that that can work. Sending a PM.

rmiller64

11-19-2016, 11:36 PM

My AFR185 heads call for Felpro 1415. I believe they have a larger opening than the 1487 listed above

boat737

11-20-2016, 12:42 AM

This is not a problem. These are the same headers everyone uses. Just put some silicone on the header flanges and bolt them on. It will work.

My gasket that came with the FFR headers, looks just like, and reasonably close configuration, as the header flange I have, just not like the head ports. I PM'd Bob (above) and he was kind enough to give me some more info on all this mis-match stuff. Thanks again Bob.

So for now, I'm going to go ahead with the "no gasket" (Ultra Copper RTV instead) set-up. I'm still a couple weeks away from the first start, and those pipes will be the last things on, so I suppose I could change my mind again, who knows. Got most of the fluids, hoses, wires and linkages done. Just need to plumb in the heater and go over all the nuts, bolts, fittings and plugs one last time.

I was looking at the Stage 8 header bolts, and they have a few configurations. A "half moon" like retainer clip, a "teardrop" like retainer clip, nickel plated steel, and stainless steel, all for a 351w style header (I guess that means 3/8-16 thread). Any one have any input on which is preferred or desirable? I have 3/4' thread depth for the bolts, so I assume I need the 1" length.

CraigS

11-20-2016, 07:59 AM

Jeff Kleiner

11-20-2016, 08:06 AM

RE: Locking bolts---I have used both Stage 8 and Percy's Vibe-Lock. Both are effective but the Percy's are more user friendly. With either run through a few heat/cool cycles and snug the bolts up after each before finally locking them down.

Cheers,
Jeff

boat737

11-20-2016, 10:12 AM

WOW not a good match at all. I would try to open up the header port width a bit w/ a die grinder to at least make a bit of a funnel effect. You can't go too far because I believe that the weld is done on the head side of the flange. But any little bit will help. Unfortunately, the only real perfect solution is different heads or headers, neither of which is kind to your wallet. I bet that once you start driving your car, it will run so strong that this will fade pretty quickly to the back of your mind.

After conversing back and forth with boB above, I was pretty much thinking on running these as is. He makes some good points on running with no gasket, and designed flow and turbulence in that area. I agree, it just doesn't seem right, but I guess that's what people do. Who knew? And probably the most important, I would hate to mess up that beautiful ceramic coating, by grinding it off. They are a piece of art.

RE: Locking bolts---I have used both Stage 8 and Percy's Vibe-Lock. Both are effective but the Percy's are more user friendly. With either run through a few heat/cool cycles and snug the bolts up after each before finally locking them down.

Cheers,
Jeff

Shoot, and I was all set to get the Stage 8. The Percy's look nice, but the wire ring and star washer look kind of fragile/under designed. Do they hold up under the extreme temperature environment? And the big question, Black Oxide or Stainless?

Thank you all.

edwardb

11-20-2016, 10:31 AM

Shoot, and I was all set to get the Stage 8. The Percy's look nice, but the wire ring and star washer look kind of fragile/under designed. Do they hold up under the extreme temperature environment? And the big question, Black Oxide or Stainless?

Thank you all.

I've used both as well and agree with Jeff the Percy's are more user friendly. Very simply, they lock in whatever position you like. The Stage 8's need to be in a position where the retainer fits properly or trimmed to fit. Plus the snap rings are a little more work (and easy to fly off and lose...). The Percy's are plenty strong and hold up just fine. You're on your own with the color. I did SS. But they're not very visible.

boat737

11-20-2016, 10:46 AM

I've used both as well and agree with Jeff the Percy's are more user friendly. Very simply, they lock in whatever position you like. The Stage 8's need to be in a position where the retainer fits properly or trimmed to fit. Plus the snap rings are a little more work (and easy to fly off and lose...). The Percy's are plenty strong and hold up just fine. You're on your own with the color. I did SS. But they're not very visible.

Thanks Paul. I have .75"+ thread depth in the head, and a .375" header flange, so the 1" length sound about right? And even with the locking feature, do you still use Loctite or RTV on the threads? I guess that would preclude re torquing...

Jeff Kleiner

11-20-2016, 11:02 AM

...And even with the locking feature, do you still use Loctite or RTV on the threads? ...

No, but ABSOLUTELY use anti seize (unless you want to pull the threads out of the head should you ever need to remove the bolts :( ).

Jeff

boat737

11-20-2016, 11:10 AM

Thank you Jeff (and all the other proffessionals and experts that offer all this free and valuable help. How do you guys ever make any money "giving it away" like that?)

Anti seize I got. Nasty stuff, worse than silicone. No matter how hard I try, how careful I am, I still manage to get in everywhere I don't want it, face, hair, clothes. That stuff has a mind of it's own.

I'll order up the Percy's right now. Stainless. Nothing but the best.

edwardb

11-20-2016, 11:17 AM

Thanks Paul. I have .75"+ thread depth in the head, and a .375" header flange, so the 1" length sound about right? And even with the locking feature, do you still use Loctite or RTV on the threads? I guess that would preclude re torquing...

1 inch sounds about right. You want to engage the maximum threads without bottoming out. Agree as well about the anti-seize.

rmiller64

11-20-2016, 02:34 PM

My AFR185 heads call for Felpro 1415. I believe they have a larger opening than the 1487 listed above

I stand corrected that the Felpro 1487 has a larger port open than the 1415 that my AFR185 heads call for. I'm wondering since the 1487 gasket is designed for the Port Style: Dart and Trick Flow spread port which both have a raised exh port that is what maybe causing the miss alignment and sealing issue with the FFR headers? I chose the AFR185 due to the standard exh port location vs. a Raised Port.

Fel1487 Dart and Trick Flow spread port

Port Height (in): 1.620 in.
Port Width (in): 1.420 in.

Fel1415 Small Race Port, Ford, Small Block

Port Height (in): 1.480 in.
Port Width (in): 1.250 in.

NAZ

11-20-2016, 03:11 PM

Agree with Jeff & edwadb on using anti-seize -- consider it a requirement if you ever want to remove the fasteners without damaging the aluminum. Steel in aluminum has a problem with galvanic corrosion and the longer the parts are assembled the harder it is to remove the threaded fasteners without galling the aluminum. You should also use anti-sieze on your spark plug threads (keep it off the electrodes) for the same reason. Not all anti-seize products are the same and vary in performance based on the metals they are protecting. For steel in aluminum I like a graphite based anti-sieze and you can get this at Aircraft Spruce online or Google Champion Spark Plug Anti-seize for aircraft engines. An alternative is a zinc based anti-seize and several companies make zinc dust anti-seize.