HP exhaust manifold questions

[bull]

How do these manifolds bolt down where the deep holes are? Bolts? My engine builder put studs in all the holes so I guess I'll have to change that if that's the case. And why is one of the holes bigger in diameter than the other. Does the one on the right have a sleeve/spacer in it?

[UFO]

There are long shank nuts that are used.
As for the smaller hole in your pic,kinda looks like a shank has rusted into place with the hex top broken off.

[Just 6T9 CHGR]

1 short one on drivers side & 2 long ones on pass side...

Our own Bill Allphin sells a nice complete kit to mount these....



Kit # H8065

http://amhightechauto.com/

[8WHEELER]

Curtis, there is some kind of sleeve in the right hole, as you can see there is originaly a sleeve nut
in both of those to holes. So both holes should be open like this.

Dan

[bull]

Thanks guys. I wonder how I'm going to get that sleeve out of there.

Hey Dan, do you know if there's a kit to replace that heat riser flap as shown in your pic? Mine is all busted up and most of it's gone. That must be your new repo Year One manifold set. Did it work out pretty good for you?

[Nacho-RT74]

only NOS buddy... and prices can get up to $120 rate

[bull]

only NOS buddy... and prices can get up to $120 rate

I'm kind of eye balling that $500 Year One item HP689S like Dan has pictured above. By the time I mess around getting the rusted sleeve out, locate and buy a heat riser kit, buy a fastener kit and get my manifolds ceramic coated how much money and time would I be out? And then, if I could maybe get $150 or so for my old set...

[b5blue]

That "Mardison nut" will drill out, but I been drooling over those new ones from Y1 a long time too. 

[8WHEELER]

I have only seen a couple NOS heat riser flaps for sale in years, and they went for crazy money.
If year one had the manifolds made, why can't the make the heat risers    probably
because people would never buy the manifolds if they did.

This is the main reason I don't like the YO manifolds, great big Y1 on the inside of them, but
not sure how noticeable they are on the car.

Plus I like the actual cast date on the originals, like 11-17-67

I actually bought a couple sets when they put them on sale big time, and
they gave me a discount on top of that, final price........... $259.00 a set,
and that comes with all hardware.

Dan

[Just 6T9 CHGR]

You might only see the Y1 on the drivers side manifold.....not so much on the pass side

[bull]

I was able to knock that "sleeve" out last night. Turns out all it was is what looked like a lock washer jammed into the very end of that hole. The flap is still there and it moves but the heat coil and riser portion is gone. Someone had just wedged a chunk of metal under the arm to keep the flap open.

If year one had the manifolds made, why can't the make the heat risers    probably
because people would never buy the manifolds if they did.
Dan

They apprently won't sell just one manifold either. And now they're $500/pr.

[bull]

So, Dan, how do those manifolds work? Can you actually see the Y1 when mounted?

[UFO]

You might only see the Y1 on the drivers side manifold.....not so much on the pass side

Take a grinder to it.
A light touch will make it go away.

[maxwellwedge]

only NOS buddy... and prices can get up to $120 rate

I'll take 4 at that price!

Bull - I had a heat riser flap seize shut once and it burned a valve on my motor - nasty stuff. Ever since then, I put all the stuff on (to look right) but grind the flap down to just enough to keep the shaft centered in the manifold.

[Chatt69chgr]

I had heard that they tend to rust in place and quit working.  So a lot of folks will either take the heat riser valve flapper out and plug the holes or better yet, do what you did and that way keep the external appearance.
I got a set at the $259 price too.  Wonder why they are $500 now?

[Nacho-RT74]

only NOS buddy... and prices can get up to $120 rate

I'll take 4 at that price!

Bull - I had a heat riser flap seize shut once and it burned a valve on my motor - nasty stuff. Ever since then, I put all the stuff on (to look right) but grind the flap down to just enough to keep the shaft centered in the manifold.

welll around a year since I saw that one LOL.

I have a NOS unit but for 70s Small block... just one piece missed, the V or W shaped spring.

[jasonjb75]

I got a set of the Y1 manifolds myself, they seem to be pretty good quality.  In fact I didn't even see the Y1 until the pictures on here.

What was the main purpse of the heat riser valve anyway?  When it was closed where did it circulate the exhaust gas?  I know mine was pretty screwed up for some time, in fact that is the reason I bought the new ones, but if it stayed closed could that do any damage to the engine?

Just trying to figure some things out!

Thanks,

[maxwellwedge]

Look at my post above on the heat riser sticking shut.  Not nice.   

[jasonjb75]

I guess I should give up speed reading.....

[62 Max]

I have only seen a couple NOS heat riser flaps for sale in years, and they went for crazy money.
If year one had the manifolds made, why can't the make the heat risers    probably
because people would never buy the manifolds if they did.

This is the main reason I don't like the YO manifolds, great big Y1 on the inside of them, but
not sure how noticeable they are on the car.

Plus I like the actual cast date on the originals, like 11-17-67

I actually bought a couple sets when they put them on sale big time, and
they gave me a discount on top of that, final price........... $259.00 a set,
and that comes with all hardware.

Dan

Maybe I should get rid of mine.

[b5blue]

The heat was forced back over the intake crossover to the other sides less restrictive flow.

[SeattleCharger]

I had heard that they tend to rust in place and quit working.  So a lot of folks will either take the heat riser valve flapper out and plug the holes or better yet, do what you did and that way keep the external appearance.
I got a set at the $259 price too.  Wonder why they are $500 now?

have heard the same thing, my set had the riser removed and holes filled up, guy said they get stuck too often over time and are a pain, better off without them

[b5blue]

With a heat blocked off valley pan (as in for an aluminum intake like my six pack) It would only restrict the exhaust flow and do nothing good anyway.