Need help NON mopar 1967 Pontiac Lemans 326

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Timing chain play? Ponchos were the original notorious nylon cam gear tooth shredding specials, but since the cams been swapped, that should be less likely........maybe
the cam is installed wrong or is a POS cheap cam. My one time friend long ago bought a J.C.Whitney special for His Poncho 400, His Dad(Who taught Me how to shrink
sheetmetal after I had it stretched out welding) did a nice job of re-doing the car Electric Blue Poly white vinyl roof '73 Catalina Coupe, beautiful car. He put the stick in
it and it didn't idle for s#*t, and wouldn't get out of it's own way. Looking all over for leaks and this & that, called Me, I didn't find anything wrong either so I said "yank
it". Took it to My place and set up some V-blocks and a dial gauge,.........2 of the intake lobes would stop .020" short of the base circle for an extra like 40deg!!
Not sayin' it is, but bad cam or cam timing/install certainly, a flat exhaust lobe will do this exact thing.....sounds just like half of the 305 Chebbies when that occured.
 
Killer6 said:
The engine in the photos clearly is a Poncho unit. Poncho dizzys spin counterclockwise.................
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I`m not familiar with pontiac and have yet to find a good image of a 307 they put in pontiac.
So thinking they may resemble the rest of the lineup and seeing they have a different rotation, I figured it was a valid question. We learn something new every day.
All I know is if I owned a 72 307 ventura, I would`nt go in the parts store and tell them I have a 72 olds. Back to the backfire...
 
BTW, We had 2 '66 LeMans' when I was a Lad, the Gold one was a 326 4bbl. 4spd.,the Burgundy one was a 326 4bbl. auto, both black int. buckets & full consoles, black
vinyl tops. We sold the Gold one for $400 in ~'75, while it was for sale someone stole it & joy rode it till it ran out of gas, lol. The other My Dad practically gave to My Cuz
'cause the THM350 was on it's way out, it never got the chance, He wrapped it right around a pole less than 2 months later.............
 
mopar head said:
I`m not familiar with pontiac and have yet to find a good image of a 307 they put in pontiac.
So thinking they may resemble the rest of the lineup and seeing they have a different rotation, I figured it was a valid question. We learn something new every day.
All I know is if I owned a 72 307 ventura, I would`nt go in the parts store and tell them I have a 72 olds. Back to the backfire...
Click to expand...
I don't think the GM "incest" started that early, but it wasn't long after. If GM put a Chevy 307 in another line of the NoveOmegaVenturaApollo body, I haven't heard of it.
I have seen mid '70's Olds Ninetyeights with Poncho 400's in them, and on & on, but not as early as '72......................
 
Yeah, typical GenericMotors move, that was one year only from what I can tell....chuckin' the Chebby 307 in there so they could use the same trans as the 250?
Anyway, this isn't the OP's problem, bad plugs/wires(even if new),or a flat exhaust lobe are more likely by the sound of it.
 
345277AC-94AF-42E8-B741-16BFD3939D01.jpeg
54498B23-5E9A-4673-AF6A-B51C4968CEBA.jpeg


Got the distributor clocked correctly. Double checked tdc. Set the initial to 16. Same results.

Buddy has a torch. Hooked up a rubber hose and ran oxygen under intake. No leaks.

Ran it along the carb and it picked up in the rear.

Pulled the carb off and noticed the bolts weren’t all that tight. (Stainless hardware)

The rear plug was sealed with liquid Teflon.

Sprayed some glass cleaner on the plug and hit the port with some air. Couldn’t get it to bubble
Took the plug out and used some natural gas pipe tape.

Replaced the stainless studs with new ones that came with the 3/8 carb base gasket kit.
Only found 3 fine thread nuts so one of them got a bolt.

Fired it back up and double checked it with the oxygen again. Good to go.

Didn’t pop and bang. Seemed to idle a little higher.

Probably back off the initial a little and tune the carb when I get some more free time.

Thanks for all the comments/help.
 
Killer6 said:
I don't think the GM "incest" started that early, but it wasn't long after. If GM put a Chevy 307 in another line of the NoveOmegaVenturaApollo body, I haven't heard of it.
I have seen mid '70's Olds Ninetyeights with Poncho 400's in them, and on & on, but not as early as '72......................
Click to expand...

We've all tried to explain to him several times that Pontiac did not make s 307. He ain't gettin it.
 
Well cool! All it was was a pesky vacuum leak.

skep419 said:
View attachment 1715114999 View attachment 1715114998

Got the distributor clocked correctly. Double checked tdc. Set the initial to 16. Same results.

Buddy has a torch. Hooked up a rubber hose and ran oxygen under intake. No leaks.

Ran it along the carb and it picked up in the rear.

Pulled the carb off and noticed the bolts weren’t all that tight. (Stainless hardware)

The rear plug was sealed with liquid Teflon.

Sprayed some glass cleaner on the plug and hit the port with some air. Couldn’t get it to bubble
Took the plug out and used some natural gas pipe tape.

Replaced the stainless studs with new ones that came with the 3/8 carb base gasket kit.
Only found 3 fine thread nuts so one of them got a bolt.

Fired it back up and double checked it with the oxygen again. Good to go.

Didn’t pop and bang. Seemed to idle a little higher.

Probably back off the initial a little and tune the carb when I get some more free time.

Thanks for all the comments/help.
Click to expand...
 
But check this out........

Pontiac Ventura - Wikipedia

If you click on the "307" link in the article, it of course links to a small block Chevy engine,but 1972 IS earlier than I thought GM did the engine swap thing. Ha! Learn somethin new everyday!

I did know some GMC trucks early on got Pontiac motors. Used to know an old guy around here who had one.
 
Never seen a 305, but they made a 301. Gutless wonder even with a turbo.
 
RustyRatRod said:
Never seen a 305, but they made a 301. Gutless wonder even with a turbo.
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Had an Indy 500 edition Firechicken in the shop not that long ago, 4.9 Litre Turbo, oddly configured intake ports. All I know is they were a snack for My Buddy's 400 T/A,
around '83 or so, not close. The turbo doesn't look any bigger than a T-type Buick, We had an early T-type Riviera, think it was an '83 I think.......
The Guy with the Catalina spun a rod brg. in the 400, so He dropped a 301 in to run around while he built a 455 for it, talk about ridin' a torque curve rollercoaster!!!
 
How many of yall knew about these? A "half Pontiac". LOL They came in early stuff like early 60s Tempests and what not. Half a 326 I think is what they were. Pretty different. And yes, you see an early Rochester 4 barrel on it. The Rochester 4 jet. LMAO

Half Pontiac.jpg
 
Here's another shot. Since it's 195 cubes, that means it's half a 389. That's pretty cool!

HALF Pontiac1.jpg
 
Mickey Thompson was famous for makin some Hemi heads for the Pontiac V8. Here's a project probably few people know he did. A blown and injected Hemi Poncho 4 cylinder.

BLOWN HALF PONTIAC.jpg
 
RustyRatRod said:
How many of yall knew about these? A "half Pontiac". LOL They came in early stuff like early 60s Tempests and what not. Half a 326 I think is what they were. Pretty different. And yes, you see an early Rochester 4 barrel on it. The Rochester 4 jet. LMAO

View attachment 1715115048
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Yeah, that would honk some hooter..:)
 
RustyRatRod said:
Mickey Thompson was famous for makin some Hemi heads for the Pontiac V8. Here's a project probably few people know he did. A blown and injected Hemi Poncho 4 cylinder.

View attachment 1715115051
Click to expand...
Yes M/T , did exactly that.,...and he thought " outside, of the box " Thank You ,Rob... Done a couple of Pontiac.. bullet proof , but very touchy on tuning .Perhaps a P.M to member ...VOETOM ,might be an,option. He kinda actually knows, Pontiac.
 
RustyRatRod said:
How many of yall knew about these? A "half Pontiac". LOL They came in early stuff like early 60s Tempests and what not. Half a 326 I think is what they were. Pretty different. And yes, you see an early Rochester 4 barrel on it. The Rochester 4 jet. LMAO

View attachment 1715115048
Click to expand...
knew about it just never seen one!! that M/T build is cool micky did alot, sad he got shot!
 
RustyRatRod said:
Probably spunk up a Pontiac Astre purdy good with a 5 speed 'hind it.
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Yea ,It would.. I see you ablaze in the southern sun... with the sunroof open.. work that gearbox.. Sorry O.P ... and Rob .. just a light hearted jab ,for humor.
 
Abodybomber said:
Yea ,It would.. I see you ablaze in the southern sun... with the sunroof open.. work that gearbox.. Sorry O.P ... and Rob .. just a light hearted jab ,for humor.
Click to expand...

Yes, with my 70s blown dry hair and my ultra hot chick with her boobs poppin out in the passenger's seat. Yeah, I see your vision. LOL
 
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