# left side exhaust downpipe modification?? auto trans



## sameold01 (Jun 21, 2020)

Is there an aftermarket pipe I can buy to work around the starter to avoid a heat soak? Stock YS manifolds I believe they are 2" on the manifold. Thanks. Or any information will help!

1969 GTO convertible Auto trans.


----------



## PontiacJim (Dec 29, 2012)

sameold01 said:


> Is there an aftermarket pipe I can buy to work around the starter to avoid a heat soak? Stock YS manifolds I believe they are 2" on the manifold. Thanks. Or any information will help!
> 
> 1969 GTO convertible Auto trans.


I think "heat soak" is an over used term when people cheap out on the correct positive cable wire size, corrosion gets into the Purple wire, bad battery connections on either end - especially the cable ends on the battery you have to strip the cable and bolt under the hold-down tab, improper case size/cold cranking amps of the battery selected, the original starter has never been rebuilt or a cheapo rebuilt/offshore unit was installed, a solenoid heat shield was never installed or removed, the timing is not set correctly and it labors hard each start until it fails, the air/fuel mixture is set to lean causing high exhaust temps, or engine/block temps run high all the time.


That said, the pipes are not the issue. Most often the solenoid will fail first and you can go through several of these on the same starter. You can wrap the pipe with insulation, but this typically can trap moisture between the wrap and pipe and the pipe will rot out faster. A solenoid heat shield can be of help. Heavy correct gauge positive cable like factory can be a big plus - the auto store's skinny wire isn't doing you any favors.


Get a mini-starter that has more cranking torque and can position the solenoid down and away from the pipe - like RobbMc. You will most likely have to modify your cable and possibly extend the Purple wire.


----------



## sameold01 (Jun 21, 2020)

Thanks Jim. Being this car is 52 years old and only 45 K miles on it I'm sure it might have some issues. The powertrain has never been out of this car yet. I have .4voltage drop on the ground side of the circuit and that is in check. New cables pos and neg with good ground and this engine wiring harness is in good shape. The purple wire is plyable does bend and no corrosion. Car is in paint now and will be back in a couple weeks so I will get to it later. I did find a receipt for an acdelco battery that was bought in 1998 and if this is the same one I will change it out. The battery has passed several load test and battery analyzer checks. Thanks for the help.


----------



## PontiacJim (Dec 29, 2012)

sameold01 said:


> Thanks Jim. Being this car is 52 years old and only 45 K miles on it I'm sure it might have some issues. The powertrain has never been out of this car yet. I have .4voltage drop on the ground side of the circuit and that is in check. New cables pos and neg with good ground and this engine wiring harness is in good shape. The purple wire is plyable does bend and no corrosion. Car is in paint now and will be back in a couple weeks so I will get to it later. I did find a receipt for an acdelco battery that was bought in 1998 and if this is the same one I will change it out. The battery has passed several load test and battery analyzer checks. Thanks for the help.


OK, sounds like a plan. Batteries in my book only seem to last about 5 years. If the car still has the original starter, always keep it and have it rebuilt rather than use an aftermarket rebuilt factory style replacement. Sometimes the factory used shims to get the starter lined up so it would not grind the flywheel gears - just normal stuff. But if you use a different starter, you may run into now having to add this shims and re-align the replacement starter - which is not a big deal, just that you can save a little work. You may already have shims, if so, pay attention to them and re-install them if you rebuild your starter. Write down date codes/numbers on your starter to make sure it comes back as your and let the rebuilder know you want yours back, not another one.

Now the aftermarket mini starters like RobbMc will tell you to check the gear clearance between starter gear and ring gear - this too is normal. Then shim if needed. They will have directions, or should, and this has been covered here in the past on the forum so you can do a search if need be.


----------



## sameold01 (Jun 21, 2020)

There is a napa starter new on the car. He gave me 2 1969 starters that need rebuilt and I believe he said 1 is the original. Let me get those rebuilt and i will swap them out. yes there were 4-5 shims on the starter i looked at. Thanks


----------



## PontiacJim (Dec 29, 2012)

sameold01 said:


> There is a napa starter new on the car. He gave me 2 1969 starters that need rebuilt and I believe he said 1 is the original. Let me get those rebuilt and i will swap them out. yes there were 4-5 shims on the starter i looked at. Thanks


OK, I'd get the original rebuilt as it is most likely a better candidate than the NAPA unit.

You may not need the 4-5 shims when installing the replacement starter. Those shims may or may not have been used with the original starter and could have been added for use with the NAPA starter, so it may be trial & error to see what you will need.

If you do not have the starter brace which is found on the back of the starter and bolts to the block, you may want to add this at this time. They give additional support to the starter and some cars had them some did not, and people also removed them.

Here is one and the diagram as how it is installed.









64-69 Pontiac Gto Lemans Firebird Engine Motor Mount Starter Brace Bracket V8 | eBay


INL10884 - 1964-70 Pontiac V8 Engine Motor Mount Starter Brace. Bolts to the motor mount bolt and the end of the starter 1pc. <br>This is the bracket that is used to support the end of the starter. The bracket mounts to the motor mount bolt and to the stud on the end of the starter. <br>This...



www.ebay.com





I would also add the solenoid heat shield as well. Simple item that can help as my experience as noted, is the solenoid fails before the starter does. Attaches to the screw that holds the solenoid to the starter and one of the screws on the back of the solenoid. Says for RA manifolds, but it fits all Pontiacs.









1967-69 Pontiac (All Models with Ram Air Exhaust Manifolds) Starter Solenoid Heat Shield


1967-69 Pontiac (All Models with Ram Air Exhaust Manifolds) Starter Solenoid Heat Shield




www.inlinetube.com


----------



## sameold01 (Jun 21, 2020)

I have the original brace on the car. I have the log style exhaust manifolds on there for now. What exhaust manifolds do you recommend?


----------



## PontiacJim (Dec 29, 2012)

sameold01 said:


> I have the original brace on the car. I have the log style exhaust manifolds on there for now. What exhaust manifolds do you recommend?


The cast iron repop RA exhaust manifolds seems to be the best route. Get mandrel bent head pipes to go with them. 

You will also have to re-route your batter cable and get the correct parts to do this. Again, aftermarket, and this has been covered here on the forums by doing a search.


----------

