stellar

At 1st I also thought 180 degrees out, but am now thinking a bad starter. Not only is the starter now being used way under powered for the application it may also have bad windings in it that will only show under load. In either case I strongly recomend replacement of the starter before you spend any more time on this.

bob p

Those numbers aren't really helpful, as they don't cross-walk over to a starter number that I can actually buy. It doesn't help to be told to buy a 1107776 when a 1107776 isn't for sale.

I'm encountering problems with the data that I didn't anticipate running into. In addition to talking to you, I've been spending a couple of days talking to the director of AC Delco-Remy Tech Support, and the data that I'm getting from him doesn't match the data that I'm getting here. According to Remy, the 1108746 is a pad-mount starter that won't even bolt onto my 396 engine's flange-mount. My 1108746 has a flange mount. Somebody has bad data or I own a starter that doesn't exist. More on that later. In this post, I'd like to focus on the problem of lack of availability of the necessary service data for my classic Oldsmobile.

Unfortunately, I can't find the technical information that I'm looking for anywhere on the internet, and I don't have access to the reference materials that you appear to have. I appreciate the help that you are offering, but maybe you don't realize how frustrating it is when I need to look at a complete applications table to sort through all this, and instead of getting what I need to solve the problem, the data gets rationed out one bit at a time over a period of several days.

I need to look at a copy of the application look-up table, so that I can be independent and solve this problem on my own. Without it, I'm forced to be entirely dependent upon someone else reading a table and typing something for me, and then following-up with several days of back and forth chatter on the internet. Being prevented from solving the problem on my own and being forced to get the data in snippets is a very frustrating way to try to fix a car.

The data rationing paradigm effectively prevents me from solving this problem on my own and makes me totally dependent upon getting bits of information from someone else. Is there any way to solve this problem? I'd really like to fix my car, without having to try to piece together incomplete snippets of information that I get from Delco-Remy and the helpful people here. Being the subject of a number of $5 and $20 bets from guys who are being entertained by my problem doesn't help things either.

Please don't take this the wrong way – I appreciate all of the help, but what I need is to get my hands on the application tables. They're not available on the internet, but people here seem to have them. Where can I get access to the data that I need to fix my car?

MDchanic

Look, you're driving a car that's half a century old, and they don't make parts for it anymore.

They make parts that are close, but the original parts are no longer made.

I got my Olds information from the 1972 Oldsmobile Parts Manual, which is available from WildAboutCars for a $20 (annually renewing) membership to the non-profit Automotive History Preservation Society. They've also got the 1975 Parts Manual and the Service Manual and Supplement for your car.

That won't help you though. Those two numbers are all there is.

You strike me as an engineer, probably Electrical or Software, possibly Mechanical, but an engineer.
Engineers need data so that they can make decisions about how to solve problems within given parameters. Data-poor environments make their brains bleed.
Unfortunately, what we have here is a data-poor environment.

As for your current starter, I have not seen it, but based on the number stamped (not embossed) on its case, it is a starter for a Chevy straight-six from the mid-1970s (which is what the poor tormented Delco rep said, in different words). The starter that corresponds to that number is a short-case, low-torque starter, which will not reliably start your car.
As I was saying to somebody else, just today, it probably had enough torque to start your car ten years ago, but now, with the passage of time, and the addition of a few ccs of oil to your rings, which has increased your compression by a few pounds, it no longer has enough torque to turn the motor (and will overheat and burn if forced to).

The way that this situation arose is that your starter was "rebuilt."
When a starter is "rebuilt," it is sent to a factory where people disassemble it into its constituent parts, those parts are industrially cleaned and painted, then sorted into categories: Cases, rotors, drives, noses, brush holders, etc.
New starters are then assembled from these bins of parts, with certain parts being replaced with new units (such as brushes) and others being retained if intact (windings have continuity, bearings the right diameter, commutators smooth enough, or turned down, etc.).
In the course of this process, subtle details, like the differences between cases and their internal windings, are generally ignored. This goes more for some "rebuilders" and less for others, but it is the way it is.
Because of this, it is entirely possible for the case from a Chevy straight-six starter to have been mated to the nose of an Olds 394 starter and sent out to live underneath your engine for a few decades, which I expect is what happened.

Unless you go out and buy a whole bunch of starter motors for parts and disassemble them and check them very carefully, until you find the parts you need, you are not going to fix this problem yourself.

Just send a message to Mark (Stellar) above and you can arrange to have him rebuild it - he is a professional rebuilder with forty years experience, and can have it back the way it was when it left the factory.

Or at least, that's how I see it...

- Eirc

bob p

Rebuilt. This is the original starter body that has been on the car for 20+ years and was used in daily driving. Only the internals have been rebuilt, and when I had the starter rebuilt locally I specified that it had to be rebuilt for the high-compression 396. I think that the old man at the auto electric rebuild shop understood exactly what I was telling him.

I'm not sure how you reached the conclusion that "It does not test strong." My comment was that AutoZone wasn't capable of performing a load test on any starters, not that my starter failed a load test. Yes, we know that the car is having trouble cranking, and there are two hypotheses that can explain that -- a) too much load in a sticky engine, and b) bad starter. At this point both of these remain unproven hypotheses, I am still hesitant to draw a firm conclusion about one hypothesis or the other.


Remy's technical support director tells me that 1108746 was used in many GM applications and is not unique to Chevy. He also tells me that it has a pad mount, while mine clearly has a flange mount. In other words, it's pointless to pay much attention to the number on the case, as the case number and the mount do not go together. Obviously, this starter has been rebuilt, in the same way that you recommended rebuilding a starter from appropriate parts, so we have to not focus on the part number. Irrespective of what's inside, the wrong number starter had the right parts inside it, as it worked well on my car for years.

My starter appears not to be what it's body number says it is, because it has a mount that it's not supposed to have. Yes, it has the copper spacer sleeve, and the long high torque windings inside. The guy who did the rebuild knew exactly what application he was rebuilding for when I took the starter in to be rebuilt.

The reference that it corresponds to a short-case has to be wrong. My fugazi 1108746 definitely has the numbers stamped into a long case. It has the copper spacer. (I had it rebuilt with high-torque internals.)

That said, the Remy crossovers for all of these starters are long case:

* the Remy crossover for 1108746 is the 25367, which has the copper spacer.
* the Remy crossover for 1107776 is the 25233, which has the copper spacer.

It doesn't look like idea of checking for the presence/absence of the spacer is going to give us the answer. It was a great idea, though.

Now, looking closely at the Remy data, both the replacement for the 1108746 (25367) and the 1107776 (25233) are the both the same. They both use the "DRWD10MT" internals, and it would appear that only the mounts are different (pad vs flange). Both have 1.2 kW ratings. In other words, in this era when the antique parts may have been different, the modern replacements are all the same.

I've already taken in apart, but my 1961 service manual is still coming in the mail. It's good to know that it will contain helpful information.

Thanks for posting that. That is helpful information. Can you tell me where you got that data so that I can look at it, and/or take it in to the rebuild shop if that's what I end up needing to do? As you know, everyone who services these things wants to see the data in print -- nobody is willing to go by posts that were made by some guy on the internet. This illustrates exactly why I need direct access to the data.

Regarding the hunt for parts, I have no idea how to find rare oddball starters like the ones you are referring to. I honestly don't know how anybody could do that, unless they were someone who owns an auto shop who collects old cores, or is some collector who is willing to spend years looking for a starter at swap meets. I'm not either one. I need to fix my car now. I don't have the ability to find antique collectable starters. I only have two options -- to buy something over the counter that is readily available, or to take what I have to an auto electric shop that can rebuild it with the internal parts that are appropriate for the application.

MDchanic

If the starter was rebuilt by a starter shop, then I would recommend bringing it back there.

It did not test strong at AutoZone - it only spun. You can only tell how strong it is by measuring its torque, which they were unable to do, so you have no proof that it is good. A good starter shop should be able to load test it, though.

If the shop you brought it to before has moved / gone out of business / died, then I would recommend sending it to Stellar, and he will make it right.

The only way to find old starters, as with so many things, is to add time. With the passage of time, many things are possible, like the pile of old starters under my workbench. They just seem to accumulate there.

As I said in my previous post, join WildAboutCars and you can download all the manuals you like.
Pictures of your starter's windings are in the 1962 Oldsmobile Service Manual, pages 13-20 and 13-21.
Pictures of others years' windings are in other years' manuals. I happen to like 1968, where they are on pages 13-19 and 13-20.


You're entitled to choose your hypothesis, but as far as I'm concerned, you've already disproven the friction hypothesis by turning the engine over with only a ratchet, so that leaves only one other.

- Eric

bob p

Got it.

It looks like we've been cross-posting. I found some additional data that I updated in my last post:

The reference that 1108746 corresponds to a short-case has to be wrong. My fugazi 1108746 definitely has the numbers stamped into a long case. It has the copper spacer.

the Remy crossovers for all of these starters are long case:

* the Remy crossover for 1108746 is the 25367, which has the copper spacer.
* the Remy crossover for 1107776 is the 25233, which has the copper spacer.

Looking closely at the Remy data, the replacement for the 1108746 (25367) and the 1107776 (25233) are both the same. They both use the "DRWD10MT" internals, and it would appear that only the mounts are different (pad vs flange). Both have 1.2 kW ratings. In other words, in this era when the antique parts may have been different (high vs low torque), the modern replacements are all the same. the problem is that we don't know whether they're the same high torque or the same low torque. All that they tell us is 1k2W.

I'm going to take the starter to the shop that rebuilt it and see if they can load test it.

If I end up needing to buy something new over the counter, my inclination is to go with something like the remanufactured 25233 by Remy. I can't wrap my head around the 1k2W specification. Is that high torque or low torque?

MDchanic

I do not know the range of normal current specifications for GM starters, but I do know that the starter on my motorcycle is spec'ed at 1.2Kw and 270A.

Normal starter draws for cars are in the 200A range, but high torque starters can draw 400A when they first start to move (they draw more current when stopped or moving slowly because at lower speeds there is less resistance to current flow, or "back EMF").

I am not sure at which point the power spec. is determined, but a starter drawing 200A at 12V would be using 1.2Kw.

It sounds like you're on the right track to me.

- Eric

stellar

Armature # 1941888 hi torque 23 bars on the commutator--Field # 1949332 superseded to D4238. . Don't be suprised if the rebuilder can not load test the starter. Most do not. Me included. If he knows what he is doing is isn't necessary to load test as faults can be found without it, but you must know what you are doing. If you take the starter apart count the commutator bars. If you have 27 it is a low torque armature. 23 is a high torque. It should have 2 large and 2 small (shunt) fields.

stellar

Watch what you say about old men in generator shops. We may take offense to that. You would be hard pressed to find a young man at a generator shop. It is like trying to find a young dinosaur. Maybe you can take some pictures of what you have.or maybe if you tell me where you live I may be able to find a rebuilder or talk to your rebuilder to get you what is needed. Or you can send it to me. If it is good I will tell you it is good or if it is bad I will fix it right. If you take it to your OLD rebuilder, the numbers I gave you should be enough for him to get the right parts for you.

bob p

While you guys were posting I went to the auto electric rebuild shop. Believe it or not there were lots of young guys there. And a middle aged guy. No older gentleman this time. Go figure. They did a free spin up but they couldn't do a load test either.


They immediately recognized the starter as a 10MT. that was encouraging.

It turns out that my 1108746 case is a long case, presumably with short internals. My specimen has two holes, one for hookups to the short (low torque) or long (high torque) internals. The case looked like it was originally used for a short length/direct tab connection, and had been modified at some point by adding a second hole for the spacer and the high torque internals. Suffice it to say that the number on the case has no real meaning any more.

Inside they told me were high torque components. I wasn't able to count poles because you posted that information as i was leaving the shop. The armature looked like something had been dragging on it. The brushes looked brand new, and all of the internal wiring looked fine. The bearings looked old. I'm having them rebuild it. I dropped it off at quitting time so I'll pick it up Monday morning.

Thanks for the tip on 23 vs 27 commutator bars. I'll be sure to check that when I pick it up. Are the 4 flat "field coils" that mount to the inside of the case the same on the high and low torque versions? Or is there some way for me to tell them apart? When I pick this up it would be helpful to know everything that I need to know to assure that I'm getting something that is rebuilt properly, and not something just slapped together with parts that they have on-hand that may not even fix the problem.

thanks.

PS -- Looking back at those AutoZone test numbers: 104 A * 11.8V = 1227 VA = 1.2 kW

stellar

If the armature was rubbing the bushings are bad. Your field case has been modified to accept high torque fields. The armature for you application is not a common part. Many high torque armatures are common and interchangeable, but won't work for you. Your armature was used on only a hand full of starters. The windings are the same, but the shaft is different. At this point I suspect a grounded field or grounded armature. That would explain the high current draw. I will see if I can find a pic of the fields for you, so you can compare. If regular high torque fields are used it should still turn your car over easily, so if they don't look like the pic, don't panic until you try it on the car. I hope to get you the pics before Monday.

bob p

I can email photos to you, like I did to Remy Technical Support, but I can't post photos here. This site appears to have no facility for direct posting of images. If you PM me with an email address I'll gladly send photos of my starter.

The Remy people independently confirmed that my starter had been rebuilt out of a combination of parts, because the nose/mount was not appropriate for the body part number.

The final part of the email covered the question of power:

"To you question of power, we made a low torque and a high torque starter back in the day. Currently all our remanufactured starter are high torque, meaning they will crank larger engines.

You need for your car part number 1107776 = 25233. 1107665 = 25233 Both cross to the same current part number, Remy# 25233"

MDchanic

Go to bottom of page.
Click "Go Advanced."
Go a bit below message window.
Click "Manage Attachments."
In window that opens, add up to 5 images, they will be reduced to roughly 800x600.
If you "Copy Link Address" of the image links that appear under the "Manage Attachments" button, you can paste the links into the window that appears when you click the button above the message window, and the images will appear full size in the body of your message.

- Eric

bob p

I tried using "Advanced Options," then clicking on the little "yellow mountain" that appears above the text editing box. It required me to proved a URL for my stored internet images.

Somehow I missed the "Additional Options" panel below, with the image upload options. Thanks.

bob p

better late than never: this shows the two holes for the 12V bus connection between the solenoid and the starter.



the outside of that copper spacer may look bad, but the business ends have been wire polished and the electrical contacts are great.

bob p

Based upon stellar's opinion that my armature is somewhat of a rare piece, I'm suspicious that my rebuild shop might just be throwing something together out of parts that they have on-hand, and that I won't be getting the rebuild that I actually need. I hope that I don't end up with a freshly rebuilt lame starter.

It would really help to know exactly what the guts are supposed to look like, so that I can inspect the thing when I pick it up on Monday, to assure that I'm not getting scammed.

I've been looking around locally for the Remy 25223, but none of the local part stores carry it. Not even the AC-Delco wholesale supplier where I have an account. They say that they can't even order Remy from their warehouse, and that their only application for me is a starter called a Vision 3736. That's not encouraging. It seems that everyone wants to sell their own off-brand auto-store specials, which are probably not going to be a good solution either.

Now I'm hoping that my local rebuild doesn't result in a waste of $75, with the rebuild being done with the wrong parts, either out of ignorance or deceitfulness. aargh.

MDchanic

That is really weird. It's got two holes in the top.

I have never seen that before in my life. Stellar, how about you?

- Eric

bob p

^^^ I think that my starter case (in the previous post's photo) was probably modified. It probably started life as a 6-cylinder starter, with the short internals, and the case was later modified by some rebuilder to accept the high-torque internals by adding the new hole and the bus bar.

I'm looking at the Remy information page on the 25233 that they claim is the proper replacement for the 1107776, What bothers me is that it looks like a short internals arrangement, without the extension buss bar:



I don't know if this is an exact photo of the 25233, or if the photo could be an error. Looking closely at the photo, it looks like it says 1107664. I don't know the application for that part number.

I have an email out to Clint at Remy to get that question answered, hopefully with a CAD drawing of the 25233.

Here's the info page on the Remy site:

http://catalog.remyinc.com/Product/Details/25233

Unfortunately, the manufacturers are consolidating all of their SKU to streamline their inventory. Lots of starters are getting branded as "high torque large displacement" starters to streamline their parts inventory. I'm not convinced that they're also suitable for large displacement *AND* high compression.

All of this adds up to it being really hard to get a decent starter for my car.

bob p

Interestingly, Remy's 25367, which is the replacement part for my low-torque 1108746 (6-cylinder) starter with the "pad" mount, has the long body & copper bus extension. This makes it all clear as mud.



So it looks like the high torque 25233 has the short internals, and the low torque 25367 has the long internals, which is the exact opposite of what it should be.

I'm hoping that there has to be a photo error on the 25233 web page, and that the 25233 really has the long body, long internals & copper extension.

stellar

The starter case with 2 holes has been modified to accept the longer high torque fields. Thus the second hole. Yes I have seen this and have a few cases like this. Sometimes they have a rectangle cut instead of a hole and use a rectangle rubber grommet instead of a round one. The armature for Bobs starter is the same as other high torque starters in all respects except for the shaft. Bobs is about 1/2 inch shorter. There is a slight difference of length at both bushing ends, but it is negligible. You can make an armature for Bobs from a common HT armature by cutting about 1/2 inch off the drive end of the shaft and cutting a new retaining ring groove in the shaft. It also uses a spacer of 55/64 inch on the shaft drive end up against the body as a drive retract stop. This spacer is on the original armature. Or you can press the shafts out of the armature bodys and exchange them. I would not advise trying to change the shafts unless you have a good hydraulic press and the correct jigs for support. A low torque armature has narrower body than a high torque one. the low T arm has 27 comm bars and the Hi T arm has 23 comm bars. Since the field case has been modified to take the hi T fields I assume the correct armature is in there, but you never know. The low torque fields and pole shoes are thicker and shorter than Hi t fields, thus you can not put a hiT arm in a case with low T fields it won't go in . But a low torque arm can go in a case with Hi T fields but will be worthless because the air gap between the pole shoe and the arm body will be to big to allow magnetism to work. It will spin but won't have any power. So simply count the number of comm bars on the armature. If it has 23 it will be right. I suspect the problem with the starter is grounded fields or grounded armature. This would explain high amp draw under load and not turning. The fields should have two large windings and two small windings (shunts) . The shunts will slow the starter speed some, but will force more current into the larger fields to increase torque. The shunts are wire wound and not like the thick flat wind of the larger fields. Some starters used only 1 shunt with 3 large fields and some have 4 large fields and no shunt. I think any high torque fields in good condition will turn you engine over satisfactory. If the engine turns in spurts like crank then slow or stop and then the same thing over and over, you may want to insist on the correct fields. If you give the rebuilder the armature and field numbers I gave you there should be no problem. They are available. If it is done right, DO NOT expect to have the job done for $75.00 The parts to rebuild this starter will probably cost the rebuilder more than that.

stellar

I'm just curious Bob, What is your engineering degree in?

stellar

difference in common HT arm and Bobs arm.. overall length 11.031-in. 280.2mm vs 10.61in. 269.5mm comm end length from end to stop .882in 22.4mm vs .89 in 22.6mm
drive end length 4.882in 124mm 4.575in 116.2mm so the spacer on the shaft may need to be adjusted accordingly.

D. Yaros

Having gone through this entire thread, I must say I am getting more than educated on 1962 Oldsmobile/Delco Remy starters; a veritable Ph.D.!

59-59-59

Somebody just give the man a known good starter and it will be over with!! Haha

MDchanic

If I had one, it would have been in a flat-rate box already.

- Eric

bob p

Wow, great information. Thanks again to you guys for being so helpful.

I've been digging around looking for information. Last night I found something interesting in my 1966-1973 Chilton's manual. Some early Chevy engines of that era had displacements and compression ratios just like my Super 88 -- presumably they needed comparable Delco-Remy starters. My Chilton's has a chapter on rebuilding starters and a subsection about Delco-Remy starter motors. There are no specifics like part numbers and internal measurements (thank you stellar) but there are some useful bits of other information:

I got a chance to see the inside of my starter's housing, and it appeared to have four field coils simply wired in series. My 1108746 started life as a 6-cylinder starter. Looking at the field coils, the housing looked like it still had simple series-wired field coils in it, suggesting that they were 6-cylinder field coils. I honestly don't know whether the armature was the 23-pole (high-torque) type or the 27-pole (low-torque) type. I didn't know to count them at the time.

Based upon my understanding of stellar's comments, it sounds like it doesn't matter if I had the 23-pole or the 27-pole armature, as I'm already doomed if I have the 6-cylinder field coils. The high-torque armature won't fit, and the low-torque armature will result in poor starter power.

bob p

Getting back to the "diagnostics" side of things, I found some more interesting/useful information in the Chilton's manual. since this thread is evolving into a Ph.D. course on starters, I just thought I'd post this for the heck of it.

We've had a pretty thorough discussion of all of these problems by everyone who has contributed to the thread. I just thought I'd consolidate this information because the brief quote pretty much sums up everything we've talked about. For me, it helps to sort the differential diagnoses of a starter motor problem according to how much current is flowing through the system.

stellar

Bob, let me try to clarify my thoughts on your starter. It is my assumption you have both hi torque fields and armature. This assumption is from looking at your starter picture. I suspect 1 or both are grounded. If you do look, the commutator bars (copper strips that the brushes contact) will be 23. You said it looked like the armature was dragging or rubbing. This can cause the armature to become grounded.This is either bad bushings (which I doubt if it has been rebuilt recently) or the field pole shoes (metal pieces that hold the field windings in) are loose or improperly installed causing the field winding to be grounded. The pole shoes are also direction specific as they can be installed 180 degrees out. Let us know how it goes with the rebuilder and if you have any questions call me. Feel free to have the rebuilder call me if he has any questions. As rebuilder to rebuilder, we speak the same language and he will know exactly what I am talking about. Independant rebuilders (unlike chain store rebuilders ) have a sense of pride in their work and I am confidant he will do it right.

Octania

Did you ever ck the voltage at the starter case with respect to the battery (-) post while cranking slowly? It should be 0 or maybe 0.5 Volts. Anything more than that indicates a faulty ground circuit which is wasting your energy as heat. Usually makes the cable or connection hot also.

Of course the voltage across the battery while struggling also indicates the condition of the battery. The lower the supplied voltage drops, the higher the current required to do the same work, since power = volts x amps. More amps = greater losses to I^2*R, dramatically higher losses across any R such as a bad ground path.

bob p

I cleaned all of the connections with a wire wheel and I didn't have any voltage drops, but the starter was still lazy. Internally, the starter looked rough, as if something had been dragging. The rough look, poor performance and high current draw all are in agreement with stellar's suggestions about the at least some portion of internals being grounded or intermittently grounded, or perhaps even out of phase.

I guess that the high current, lazy starter paradigm could still be due to my idea of an excessively tight engine, Eric's idea of a bad / wrong starter, or Stellar's more specific idea of a grounded starter field or armature. Opening up the starter and seeing the armature wear does seem like a smoking gun to me. We'll know more when I pick up the rebuild and try it out.

I am very disappointed to see the bad internals. When I had the starter rebuilt several years ago I just bolted it on the car, the car wouldn't start, and I gave up. My rebuild warranty expired while the car was sitting.

Realistically speaking there's no reason for that wear to be there as the starter has never been used -- it's cranked a few times, but it's never fired the motor and the car has never been driven. Seeing the internal wear after a rebuild makes me very suspicious that I got a half-assed rebuild last time, and that the parts were either used and in poor condition or the workmanship was poor enough to make the parts suffer quite badly in such short order while I was dealing with a crank-no-start.

Considering that the internals looked like hell after only a few minutes of total crank time, I'm nervous about what I'll be getting back from these guys.

bob p

Stellar, would I be correct in understanding that the picture of the 25233 starter in Post 58 can't possibly have high-torque windings inside? I ask this because it appears to have the short body with the short 12V bus connection between the solenoid and the starter body, rather than the copper extension 12V busbar that I have on my modified 1108746, or that Remy has on the 25367 shown in Post 59.

Here is the 25233:



Here is the 25367:



Although the Remy site gives good information about internal components (including part numbers for repair parts) for their heavy duty starters, they offer no such information on the 10MT starters.

bob p

Also wondering how much this slow-crank problem might be related to rusty heat risers.

The 62 Sky Rocket has heat control valves installed on the exhaust. They are butterfly valves installed on a shaft that's connected to a coiled thermostat. They are located between the exhaust manifolds and the inlet to the exhaust system.

My understanding is that when the engine is cold, the termostat closes valve between the exhaust manifold and the exhaust pipe, presumably diverting the warm air elsewhere. They're quite rusty, and I'm wondering if they may be contributing to my problem. I still don't have my '61 manual to look this up -- the snail-mail is taking a long time...

I'm wondering if the car might do better without them.

MDchanic

They're not contributing to your present problem, but if they don't move and spring back freely, and can't be loosened up, they may cause problems down the line.

Generally, there is one of these, on the side of the engine opposite the exhaust pipe, held closed by a bimetallic spring, and opened by gravity (there is a counterweight on one side).

The valve, by closing off the exhaust gasses' path to the exhaust pipe, diverts them up and through the intake manifold crossover passage, which runs directly under the carburetor and the choke coil cavity, allowing both of these to warm up more quickly.
As the engine warms up, the thermostatic heat valve opens, allowing most of the exhaust gasses from that side to flow straight out, with only a small amount crossing over through the manifold.

If you hit the gas hard before the valve has opened, the buildup of exhaust pressure opens the valve against the force of the spring, and allows the engine to breathe properly.

The problem comes when, over a period of decades, the shaft of the valve rusts irrevocably to the manifold, which always occurs while the car sits unused, which is to say cold, with the valve closed. Now you have a permanent obstruction, which does not change with temperature or back pressure, and which significantly impedes exhaust flow, while also overheating the carburetor.

Since I don't drive my old cars in cold weather (rock salt), it is no big deal to me to cut out the shafts and weld up the holes, but for anyone who routinely drives in very cold temperatures, it is better to get the system to work properly.

- Eric

bob p

Thanks. I have heat risers on both sides.

I live in an area where they spray liquid calcium chloride on the roads, which promptly destroys your car from below. Here in the Great Lakes snowbelt many people have nice summer cars and sacrificial winter cars.

This car is only going to see fair weather duty, so I'm not all that concerned about it's cold weather warm-up performance. It sounds like removing those exhaust valves is going to be the answer. Good to know that they're a problem that I can worry about later on. thanks.

stellar

Yes you would be correct.

D. Yaros

My opinion would be that a rusty heat riser would have absolutely no impact whatsoever on the cranking ability of the starter. The reasons: Heat risers are mechanical devices, not electrical
Heat risers are normally closed when the engine is cold
All engines are cold when first/initially started
A rusted shut heat riser would be in the normal position of closed at initial start

bob p

I wasn't concerned about the heat riser's effect on the cranking ability of the starter, but a set of rusted shut valves in the exhaust headers will impede exhaust gas exit through the pipes, and might be contributing to what I perceive as a tight engine.

MDchanic

Not at cranking speed.

- Eric

bob p

I've got the valvecovers off. Going to set timing. How do I identify which are the intake vs. exhaust valves for 1357 and 2468?

FWIW -- I'm locating TDC on cylinder #1`using a wooden dowel in the spark plug hole, and TDC is nowhere close to the timing marks on the balancer. When Cyl 1 is at TDC the timing marks on the pulley aren't even visible.

I'm still waiting on my manual. Tracking says a few more days.

It's looking like I'm going to have to scribe a mark for TDC on the pulley and work off of that, as the marks on the pulley aren't anywhere close to being visible near the actual TDC.

MDchanic

If the pulley markings are way off, then you need a new pulley, or to have your pulley's rubber replaced.
The front pulley on your engine is also the harmonic balancer, and the rubber deteriorates over time, allowing the outer portion to "walk" relative to the inner portion.
Ultimately, they will detach entirely, which can be catastrophic.

Because your front pulley is also the balancer, if you replace it, you have to get one that is exactly the same as yours - different option configurations used different pulley setups.

As for intake vs exhaust - just follow the tracts to see which valves they lead to.

- Eric