All: I have always believed all 350 exhaust manifolds to be the same. The shop called asking about the heat riser valve I neglected to supply. I want the manifolds ported and this valve will decide if it is plausible. My question is: Did Buick make a driver side manifold w/o the need for the heat riser valve? If so, what year(s). If not, does someone have the needed part and post pix and ID? Thanks a bunch.
I went through the same thing for my 69 lesabre. Both were cracked. I ended up getting manifolds from a 72 apollo dual exhaust. I know there were different styles, but unfortunately I don't remember the specifics when I did the swap. I ordered parts from TA performance and they asked for the part # because they knew there were 2 different stlyes. Hope this helps a little
Just to clarify the parts I got from TA were the exhaust manifold bolts, not the manifolds. I got the manifolds from a local muffler shop, one of the guys happened to be a big buick fan.
I have the original motor out of my 71 GS 350 and it doesn't have the heat riser.I think the 70 GS engines don't have them either but I may be wrong on that one. Pat
If the heat riser is a big circular thing in the drivers side exhaust manifold, my 1970 Skylark 2bbl 350 (with original engine) has one, so count those out.
i believe all engines had the heat riser. it's just a little metal part that bolts to the head above the manifold at the middle two exhaust ports. all it does it allow hot air generated by the hot manifolds to rise through a tube and into the air cleaner.
Don't forget that many of these failed...and some got trashed by the exhaust shop when they installed new systems.
OK guys, I'm not too bright The motor I turned over to the machine shop was a 1970 2bl Skylark motor. I do have the the small cup shaped piece that would typically lead via hose to the aircleaner. I always thought that was the heat riser. What piece I am told I need fits between the driver manifold and the exhaust pipe. I looked under my 73 and both manifolds attach directly to the pipes. Unfortunately, I took little notice of the 70 manifolds before I dropped them off. Apparently I need to bridge the connection between the manifold and pipe via this mystery piece. Am I nuts? Have I been sent on a snipe hunt? Thanks guys.
i'm confused... okay, a related issue here...a while back i replaced my passenger side exhaust manifold...engine is a 68, the manifold was from a 70... the holes and bolts matched up nicely, but there was some kind of valve-thingy (i don't know exactly what it was) that was stuck open on the original 68 manifold, not included with the replacement...this valve was located where the manifold meets the exhaust pipe...it was hinted, but not explicitly stated, to me that this was a heat riser... okay, so help me unconfuse myself... o No: the heat riser is the tube between the air cleaner and the head on the driver's side...makes sense...the heat shield is the metal plate on the driver's side exhaust manifold...so what's that valve connecting the passenger exhaust mainfold to the pipe? and is it necessary? btw, i have dual exhaust, was originally single, maybe that figures in? scott
So I am not alone Scott: What you describe (valve thingy) is exactly what I'm getting at. My 1970 manifold had the valve thingy apparently. I want to replace with a non-thingy manifold to simply. I believe the valve-thingy aids in cold start warm-up and is activated by a temp-sensitive spring. However, I've been calling it a heat riser when I should have been calling it a valve-thingy (ha!) Does someone know where to get a thingy-less manifold? Based on my observation, the later manifolds had no thingies. But starting when?
I know the heat riser is on the passanger side of my 72 skylark. And I have no heat riser on my 70 (may have been removed) I also have a 79 350 (black) and it did not have one. So My guess is too look at late model 350's hope this helps
GS or Skylark Phil - Which '70 are you referring to? My manifold came from a 70 Skylark single exhaust. Maybe dual exhaust cars received different treatment. The car my engine came from was from CA. If that has any bearing I don't know.
Are we talking about the circular piece of metal, attached by 3 bolts to the head that is positioned in between the head and exhaust manifold? The flexible tube extends from the air cleaner to this piece to feed warm air to the carburetor to help cold engine operation. Is this it? There is a 'metal pan' that bolts to the exhaust manifold so this circular piece can be used.
No sir Marco: This piece theoretically is a valve which attaches to the manifold and then attaches to the exhaust pipe (in a linear fashion). Exhaust gas passes (ha) through this valve on its way to the exhaust pipe. (Heck, I've never seen one, but based on this thread, I presume it existed in one way shape or form in 350 history) It seems to me BB people have complained about this item seizing up and causing poor running conditons. (Here I go thinking I'm crazy again.)
That's it Phil. I don't recall exactly what it's called either. On the subject of 350 exh manifolds... when we pulled my 350 a few weeks ago to fix some oil leaks, we also replaced the exh manifold gaskets, thinking I may have an exhaust leak. Well, the ticking isn't gone, so it's probably a bad lifter. But, we had a heck of a time figuring out what was going on with the gaskets and manifolds and heads lining up. There were a couple spots where there was little to no overlap of the manifold material around the head exhaust port. We weren't too sure we were going to have a seal there... Which makes me wonder about possible differences among the 350 exh manifolds. I have 72 heads, a 71 block, but don't know the year of the manifolds yet. I did write down the #'s off of them before we put them back on, so I'm going to try to id them as to what year they are. 1383427 1236336
Cool Thanks for posting the pix, Phil. At least I know it exists. You say it is on the passenger side. hmmmm I'll have to call the shop back and verify the side. He said driver.
The heat riser shaft turns in a metal sleeve. Remove the flap and shaft, then fill the opening in the sleeve with weld. I did that once. Worked great!
