cracked intake on 66

[scotth3886]

If I didn't have bad luck, I'd have no luck at all.

Took the car in yesterday for another $1,600 of work.  The big project was to replace the intake with a really nice one I found on ebay for the paltry sum of $500.

Jeremy, whom I know to be very good with old iron, replaced the intake.  The old one had a rather huge crack, pic attached, which is a little worse than I thought it would be.

Got all done and the car was quiet for the first time for a few minutes.  Started driving the seven miles home and I noticed it getting louder again.  By the time I got home, it was pretty much as loud as what it had been before the repair??.  Just crazy.  He's going to have to go back in again.  I have a sneaking hunch that it's not the intake heat tube, which having an electric choke I don't need anyways, but that I once again have a cracked intake.  If it is, hopefully he can just braise it.

Stranger now is that every time I slow to make a right turn, the car stalls or tries to stall.  Right turn only.  Stopping going straight or a left turn is fine, but even an easy soft right turn and it does it.  Almost made me hit someone waiting to pull out and turn left because I suddenly had no power steering when starting the turn.  I don't understand the correlation with replacing the intake.  Bad dashpot could make it do it, but it would all the time when you release the accelerator suddenly I would think and not just right turn.

What on earth could this be as it's never done this before?  just as you're slowing down and just starting to crank the wheel to the right on low speed corners/turns only.

Also found that it leaking oil from valve cover gaskets (he replaced those today), fuel pump, timing cover, oil filter adapter and oil pan.  Hopefully, can do oil pan gasket with engine in car.

So next step is replace to everything from block forward: timing chain, oil pump, timing cover gasket, water pump. 

I swear, I'm going to junk this car if I don't start turning things around and have some decent luck one of these days. 

[cadillactim]

When did the stalling begin, before or after the loud noise, and it didn't happen before you switched intakes? Does the stalling seem like running out of gas or like ignition is being turned off? If stalling seems fuel related and began after intake replacement, might have trash in carb or glass bowl that is that is stopping fuel or enough of a vacuum leak combined with trash in carb/bowl. Does it stall at idle when turning right or only when car is in motion. If in motion I would be looking for trash.

Tim

[scotth3886]

When did the stalling begin, before or after the loud noise, and it didn't happen before you switched intakes? Does the stalling seem like running out of gas or like ignition is being turned off? If stalling seems fuel related and began after intake replacement, might have trash in carb or glass bowl that is that is stopping fuel or enough of a vacuum leak combined with trash in carb/bowl. Does it stall at idle when turning right or only when car is in motion. If in motion I would be looking for trash.

Tim

It wasn't a sudden loud noise.  It's just that the exhaust leak returned in a few minutes after replacement, while I started driving home.  The right turn stalling began on the way home after the intake replacement.  Never happened before the intake replacement.  It only happens at low speed when beginning the right turn.  It doesn't stall if I first stop while still going straight and then accelerate around a right turn.  Even coming in my driveway, which is a pretty straight shot with just the slightest right turn, it stalls there too.   

[Bob Hoffmann CLC#96]

That strange stalling problem was discussed on this board in the past. Do a search.
Bob

[scotth3886]

That strange stalling problem was discussed on this board in the past. Do a search.
Bob

Thanks Bob.  I found a few posts concerning a stalling issue before I posted my question.  They were a little bit different than my issue which occurs only when starting to turn right at low speeds. 

I found exploring further that my dashpot is crap so I have another one on the way.  Even if the dashpot is bad, the stalling never occurred before I took it in to replace the manifold.

[scotth3886]

I noticed something else.  When just cruising then getting off of the gas, and then getting back on, I have a slight stumble that wasn't there before. 

[gkhashem]

Now I had some similar issues on a "newer" car.  A 1984 Olds with a Rochester quadrajet. I had a bad airhorn gasket so the car would stall when turning. Also replaced the accelerator pump, bogging down on acceleration.

I would go into a turn and get a stumble, did not stall but started to. You may have a vacuum leak on the intake at the carb.

I assume he removed carb from old intake, did you replace gaskets correctly. Is new intake warped?

[scotth3886]

Now I had some similar issues on a "newer" car.  A 1984 Olds with a Rochester quadrajet. I had a bad airhorn gasket so the car would stall when turning. Also replaced the accelerator pump, bogging down on acceleration.

I would go into a turn and get a stumble, did not stall but started to. You may have a vacuum leak on the intake at the carb.

Strange thing is that mine only does it on a right turn or to be more precise, when I let off of the gas and start to turn the wheel to the right.  Coming to a stop going straight or turning left, it's fine. 

He's going to take it apart again when we do the refresh on the front end of the engine. 

[scotth3886]

Now I had some similar issues on a "newer" car.  A 1984 Olds with a Rochester quadrajet. I had a bad airhorn gasket so the car would stall when turning. Also replaced the accelerator pump, bogging down on acceleration.

I would go into a turn and get a stumble, did not stall but started to. You may have a vacuum leak on the intake at the carb.

I assume he removed carb from old intake, did you replace gaskets correctly. Is new intake warped?

Correct.  Removed the carb from the old intake, and I presume he replaced the gaskets correctly, although that was the first thing I thought too. 

We'll take a another shot at it when I get all of the stuff here for timing chain and out.  Water pump is seeping a bit so when we tear into to it we do everything.  I'm told that all of that is original. 

[gkhashem]

Same for me showed up on a left curve on the road almost every time. Did it while I coasted into the turn and then accelerated. It would stumble.

[fishnjim]

That center tube is the heat cross over.   They eventually abandoned this design, but it's a common issue with older manifolds and heads that have this "carb de-icing" feature.

Most people plug them off.   Center is heating and sides are cooling so stress builds up.  I suspect it happened because it was freshly torqued.
Cast gets brittle on repeated heat cycling, so unless you change material or eliminate the issue, this will continue.   I'd tried to find an aluminum (racing) manifold for this motor.

[35-709]

"I'd tried to find an aluminum (racing) manifold for this motor."

Don't think you will find much in the way of any aftermarket intakes for the 429, or any other aftermarket pieces, not a popular engine to modify.  Those manifolds can be problematic, since you have an electric choke I would certainly block off that heat passage when you take it back apart and make sure the heat riser is gone, or at the very least, wired open.  Olson's Gaskets makes an intake gasket for the 429 with the heat passage port blocked ---  https://www.olsonsgaskets.com/products/#searchGaskets  --- which tells you something.  Put Cadillac in the search box at the link above and the gasket you need will probably be the first one to come up.

[scotth3886]

"I'd tried to find an aluminum (racing) manifold for this motor."

Don't think you will find much in the way of any aftermarket intakes for the 429, or any other aftermarket pieces, not a popular engine to modify.  Those manifolds can be problematic, since you have an electric choke I would certainly block off that heat passage when you take it back apart and make sure the heat riser is gone, or at the very least, wired open.  Olson's Gaskets makes an intake gasket for the 429 with the heat passage port blocked ---  https://www.olsonsgaskets.com/products/#searchGaskets  --- which tells you something.  Put Cadillac in the search box at the link above and the gasket you need will probably be the first one to come up.

Thanks.  I'll order these.