Headers to 2.5" Ramhorns

[Effeckt]

Another quick question on these, when they came in, there was a slip in there recommending not using a gasket to mount these to the block. I'm hesitant to go that route and wanted to see what others did/used for theirs.

[rsavage]

I have never mounted exhaust manifolds without gaskets nor have I seen it done. Why go through the work only to find out that there are leaks. Stock exhaust manifolds had gaskets. Why would aftermarket manifolds, most likely cast overseas, not need them? If it were me, I'd use gaskets.

[Effeckt]

Originally Posted by rsavage

I have never mounted exhaust manifolds without gaskets nor have I seen it done. Why go through the work only to find out that there are leaks. Stock exhaust manifolds had gaskets. Why would aftermarket manifolds, most likely cast overseas, not need them? If it were me, I'd use gaskets.

That's what I thought too but I wanted to make sure I wasn't crazy. Thanks for the feedback.

[BB72CHEVKT]

I am not running gaskets based off info from this board and I have no leaks. I ran gaskets on my 69 and had leaks.

[jaros44sr]

JMHO, not saying anyone is right or wrong, but this topic has been debated a long time.....probably since the internal combustion engine was invented

I think if your surfaces are true and flat, plus using oem locking plates, you could get away with a copper shield sealant. Anyway, thats what i plan to do, and you guys will the first to know if that system fails

I think the gaskets fail because the bolts arent retoqued after several heat cool cycles, wrong bolts, and failure to use the mechanical locking plates

[NuBomb]

Has anyone bought the Wysco ones from Jegs? I'm thinking about ordering them this weekend.

[jaros44sr]

Originally Posted by NuBomb

Has anyone bought the Wysco ones from Jegs? I'm thinking about ordering them this weekend.

Na, mine were Dormanns

[Ole Beater]

They look like the dormans with all the grinding work already done.

[Rocketman72]

Originally Posted by jaros44sr

JMHO, not saying anyone is right or wrong, but this topic has been debated a long time.....probably since the internal combustion engine was invented

I think if your surfaces are true and flat, plus using oem locking plates, you could get away with a copper shield sealant. Anyway, thats what i plan to do, and you guys will the first to know if that system fails

I think the gaskets fail because the bolts arent retoqued after several heat cool cycles, wrong bolts, and failure to use the mechanical locking plates

I have no gaskets and no leaks for 10 years on my BBC.

[SierraMtns]

This is a great thread.

I have a question. I'm running old school heads with no mounting holes to run the alternator.

Would the Dorman 674-504 work? Or will I need to run the alternator on the upper passenger side?
Amazon.com: Dorman 674-504 Exhaust Manifold Kit:...





Thanks

[jaros44sr]

I m guessing that there is a enongated squared off bracket ( the pivot bracket) on the bottom of the alt. If this is the case, then there is a threaded boss that is on the exhaust manifold

Take your alt. off and post up a pic. of the bottom mount.....

[SierraMtns]

Originally Posted by jaros44sr

I m guessing that there is a enongated squared off bracket ( the pivot bracket) on the bottom of the alt. If this is the case, then there is a threaded boss that is on the exhaust manifold

Take your alt. off and post up a pic. of the bottom mount.....

Here is a pic.



You think those manifolds will work?

[jaros44sr]

I m guessing that you would not use the adapter bracket that mounts around you header, and bolt your pivot bracket directly to the manifold, so, yeah it should work....

Don t forget to buy one for the passenger side, and you will have to cut that bracket off, since it will now be facing the firewall. Unless, you buy the proper manifold

[CrewCab59]

If you don't want to use the heat riser spacer than you can use this .


CORVETTE EXHAUST PIPE FLANGE - 2 1/2" FLAT TYPE
Part#:322106
Price:6.95
Pkg:EACH
Year:1962-1974

[LostMy65]

I originally had genuine corvette Rams Horns.
The owner that I bought my truck from, had to replace the passenger side. He only used the 2" dump type. I'm replacing it with the Dorman 674-504.
Is there an adapter to go from the 2.5 dump to this pipe in the pic below?

[LostMy65]

Also, he seem to have used some pretty short bolts where he mounted them to the block.
The threads only stick out 1/4".
How much thread should there be into the engine block?

[1tuff71]

FYI guys. JEGS sells a chrome set for about $100

[Bent77]

Anyone running the center dumps on the later 70s frame? Any other useful updates?
Dorman parts are still available

[DeadheadNM]

The heat stove should fit but it’s a guess whether or not the OD of the riser tube to the snorkel would slip over the male end at the riser and it’s in the correct location. I wonder if there is a member here who has that gen vette with the riser who could take a measurement? The stove assembles with hex head short #8 screws if I recall (maybe #10?).

The plug shields will work I suspect. But, of the four there is at least one, that to the front LH head, that’s a different shape. The shield at this location is “tented” so to speak or an inverted V to encompass the temp sending unit. Offhand I can’t recall if that at the TCS sending unit was the tented style. If helpful, I can post photos of an oem shield in this style and the hex head bolts that secure these in place.

[jaros44sr]

20200614_104000 by [url=https://www.flickr.com/photos/97391199@N06

A 1971 blazer, turned down my sending unit, as I was having incorrect readings on my gauge, G1852 seems to stick in my head, but I could be wrong, if you can't find one at NAPA, he will supply one turned down for your truck.

The flat spark plug shield will clear the sender, but in retrospec, someday , I will replace with the angled one.
After I've completed a couple more heat cycles I'll bend the manifold bolt locking tabs down.
I believe the shields are tapped in the block with 1/4-20 bolts
Check your intake manifold gasket you may have blo cked your cross over port

The Eastwood cast iron coating is not holding up to my liking, someday ceramic coating.

Also I'm not fond of the the gasket for the exit port(down pipe) I use a sold sintered piece with a metal sleeve

[Green Monster]

Originally Posted by jaros44sr

A 1971 blazer, turned down my sending unit, as I was having incorrect readings on my gauge, G1852 seems to stick in my head, but I could be wrong, if you can't find one at NAPA, he will supply one turned down for your truck.

The flat spark plug shield will clear the sender, but in retrospec, someday , I will replace with the angled one.
After I've completed a couple more heat cycles I'll bend the manifold bolt locking tabs down.
I believe the shields are tapped in the block with 1/4-20 bolts
Check your intake manifold gasket you may have blo cked your cross over port

The Eastwood cast iron coating is not holding up to my liking, someday ceramic coating.

Also I'm not fond of the the gasket for the exit port(down pipe) I use a sold sintered piece with a metal sleeve

Great info, Jim. thanks for sharing photos, bolt sizes and your experience.

Can you elaborate on what you mean when you typed "Check your intake manifold gasket you may have blo cked your cross over port"? I'm not sure what the cross over port is or it's function.

That's too bad about the cast iron paint not holding up, I'm sure that was disappointing. Good to know that may not be not a viable option. Hopefully the ceramic does a decent job against corrosion. I haven't seen long term results though but for $200 it was worth a shot.

I may be overthinking this but if ceramic coating reduces the heat transfer and under hood temperatures, as advertised, the combination of ceramic coated exhaust manifolds and heat stove may actually reduce the effectiveness of warming up the carburetor. I will likely be better than running an open air filter element without the stove and riser set up.

On a side note, DeadheadNM mentioend Letric Limited temperature sending units and I had success going this route when I had incorrect readings.

Funny, this unintended project started a few weeks ago when I discovered a hole in my muffler. Instead of just replacing the muffler I saw it as an opportunity to restore the exhaust/cold start intake system. I'm sure you all know how these projects can snowball.

I appreciate your help with identifying the correct parts that go with the ram horn manifolds.

[jaros44sr]

Originally Posted by Green Monster

Great info, Jim. thanks for sharing photos, bolt sizes and your experience.

Can you elaborate on what you mean when you typed "Check your intake manifold gasket you may have blo cked your cross over port"? I'm not sure what the cross over port is or it's function.

That's too bad about the cast iron paint not holding up, I'm sure that was disappointing. Good to know that may not be not a viable option. Hopefully the ceramic does a decent job against corrosion. I haven't seen long term results though but for $200 it was worth a shot.

I may be overthinking this but if ceramic coating reduces the heat transfer and under hood temperatures, as advertised, the combination of ceramic coated exhaust manifolds and heat stove may actually reduce the effectiveness of warming up the carburetor. I will likely be better than running an open air filter element without the stove and riser set up.

On a side note, DeadheadNM mentioend Letric Limited temperature sending units and I had success going this route when I had incorrect readings.

Funny, this unintended project started a few weeks ago when I discovered a hole in my muffler. Instead of just replacing the muffler I saw it as an opportunity to restore the exhaust/cold start intake system. I'm sure you all know how these projects can snowball.

I appreciate your help with identifying the correct parts that go with the ram horn manifolds.

Let me see if I can find a pic of a intake gasket, they used to come with a n aluminum part that you could use to block off the exhaust cross over, or not, give me some time to see what I can dig up

I believe the function was to heat up the area below the carb, for cold starts

[Green Monster]

Originally Posted by DeadheadNM

The heat stove should fit but it’s a guess whether or not the OD of the riser tube to the snorkel would slip over the male end at the riser and it’s in the correct location. I wonder if there is a member here who has that gen vette with the riser who could take a measurement? The stove assembles with hex head short #8 screws if I recall (maybe #10?).

The plug shields will work I suspect. But, of the four there is at least one, that to the front LH head, that’s a different shape. The shield at this location is “tented” so to speak or an inverted V to encompass the temp sending unit. Offhand I can’t recall if that at the TCS sending unit was the tented style. If helpful, I can post photos of an oem shield in this style and the hex head bolts that secure these in place.

Thank you for the info. I can't find info on the OD or the stove pipe of the C3 vette.

Are these four the correct spark heat shields? One appears to be "tented" for the thermostat.

[DeadheadNM]

Originally Posted by Green Monster

Thank you for the info. I can't find info on the OD or the stove pipe of the C3 vette.

Are these four the correct spark heat shields? One appears to be "tented" for the thermostat.

You bet.

Yes, that is the correct heat shield for that location.

[Green Monster]

Originally Posted by DeadheadNM

You bet.

Yes, that is the correct heat shield for that location.

What is the "D" shaped notch on the other three remaining shields used for? I've seen solid shields and notched, like these. Which is correct for our Blazers?