Discussion in 'Big Block Cadillacs' started by richie49, Aug 27, 2018.
Okay lets see if I do this right
Now if you look at the thermostat pic I have a question. As long as I have fussed with the caddy I have always just replaced thermostat as needed.and I never actually measured the hole.When the thermostat opens it is supposed to close off the bypass so the cooliant goes to the radiator. The hole in the block takes a 1 inch plug and the block off part is only .912 which leaves a hole so not all water is goes to the radiator.
At least you would think so. Apparently it doesnt affect all caddys .Does someone have a loose caddy thermostat to measure the block off tab. Maybe mine is wrong ,its supposed to be caddy specific.
Richard richie 49 at Murphy's Garage
Forgot the rest. The fan up front is to move air around so it doesn't stagnat at the engine.
Not to come late to the dance and bring up a new subject, but looking at the pictures you shot I see two things. First of all that is quite an installation.
Secondly, I think you have an air flow problem. I am assuming the air comes in the top through the old Corvair vents, goes through the radiator and then is pulled down via the electric fans. That being so you so not have near enough free area for air flow, either in or out. Remember hot air goes up, and your fans are trying to make it go down into a space that is quite restricted. I don't have an answer for you but you REALLY need to do whatever you can to increase the air flow. Regarding the front end, I am not sure where the air comes in, but there does not seem to be any place for it to go after it goes through the trans cooler and over the engine. Also, that un shrouded fan is probably just beating the air, and what ever air it moves
is going around the oil cooler, it takes the path of least resistance.
Sorry to throw these things into the mix, but even with a conventional set up (radiator/fans/full grill opening, I found that I needed to increase my air flow by giving the air an exit via the fenderwells before I solved my overheating issues on my 73.
Would have to find a way to increase the flow but right now its pulling air pretty stronge thru the vents. I am going by the fact (at Least I think it's a fact ,it might not be) That air flow under car will create a vacunm under car as the air moves under and back past the hollow where the fans are supposidly drawing air down from fans.I dont have a good ideal how much opening I need to have air move freely enough after it goes thru the fans .The room under there doesn't look like much but it is the width of the radiator and 12-14 inch across .The pics doesn't show really good how much room there is. If anyone know how to address this to have better air flow please reply. I can gaurantie I don't have lots of room to try different things. I do not want to cut up the outside of body . I want it to be seen as a corvair . Nobody thinks it is a flat six or stock I can add another small radiator if it becomes nessary at the front but it would take a lot reworking the support and running piping. I like to work around that if I can.
P.S. My spelling is bad and it takes a lot to look up the right spelling so ,kinda look the other way
Dear Mr. Murphy of Murphy's Garage (BDA Rickie),
That detail was very helpful - at least for me (can’t speak for anyone else).
That said, I think the point that kzhurley posed was more focused on a possible mismatch between your crank pulley and the timing tab. They are not all the same. Earlier in this thread I posted a box of pulleys that with multiple pulleys and some of them had the little timing ‘notch’ in a different place than others. And just as crank pulleys are different so too are timing tabs. They may look the same but spacing does vary.
The only way to know for sure that your particular combination of engine crank, crank pulley and timing tab are in sync with one another it by locating actual top dead center on number 1cylinder. Then seeing it the components line up with one another. Damn, I hope that makes sense. For the record, my initial pulley and timing tab did not match up, so I know that crap happens.
Sorry if you already know all of this stuff.
About your cooling system
It’s possible that you and I are the only two on this forum who have had Corvairs, let alone V8 powered Corvairs. Over the years I’ve had close to a dozen air cooled Vairs - and three V8 Vairs. Two of the water cooled cars had the radiators in the back, leaving one with a front mounted (rear engine) radiator. I know their cooling quirks - all too well. With your front mounted engine and rear mounted radiator the temperatures you are posting are very good! That’s especially true considering the SIZE of that engine!
Radiators are a story all in themselves. I had three customs one made. When it comes to electric fans there has been a myriad (just short of a ‘shit load’). In the days before any America car had electric cooling fans everything had to be aftermarket or fashioned by you. Those Ford Windstar units (twin fans in a plastic shroud) do a very nice job.
Richard, my high flow thermostat has a 0.918" plate on the bottom
As far as thermostat size it wont matter when I get my Chevy one and block the bypass. I was just wondering how much is cirulated around the hole since it's larger.Your measurement is close so they are the same or close enough to same so I had the correct one. Thanks for checking
Opps I was thinking wrong about the timing.( me thinking is probably the problem ) Anyway The timing marker was on the engine when I bought the car and it was all original
supposibly. It always checked out or at least it didnt cause trouble with running.I think...
Not sure about your efi system, but with my megasquirt, you have trigger offset,cranking timing, and then the normal running timing..
Trigger offset is what you set to make the timing show what the efi says it is. Then you have cranking timing, which is when rpms are under, say 350rpm,, then once the computer sees 350rpm+ then it goes to idle timing..
Problem is I think, is that different systems call it different things... So its hard to explain sometimes if you're not familiar with the other persons terminology
I bet your system would do the same.. Just worded differently
I would definitely double check the timing pointer... Mechanically. It would crest alot of headaches if it is not correct..
I mismatched a pulley and pointer once and it made the timing like 14° off.. Caused lots of headaches
On my efi setup, which uses a 36-1 trigger wheel instead of distributor, I have a trigger offset to make the computer display match the timing pointer... Then I have the cranking set to 8°. Then once it starts, it goes to around 16° or so at idle... It is a stock 500.
This is just my experience but I put a plug in the bypass and used a conventional thermostat in my 500 for awhile. I saw the temp gauge get very high before the thermostat would open. I didn't like that. It was like 10 years ago and I don't recall exact temp but it was higher than you would like to see your engine operate. I got one of those John Deere thermostats after that; they operate like the Cad thermostat but lower temp.
The general agreement right now seems to think my cranking noise is that its fighting too much timing while cranking. It certainly seems so ,due too much timing either from a bad point or due to the sniper not commanding the correct timing. I'm sure that the pointer is correct so I went checking on the crank timing on the sniper.Of course you have idle timing being commanded while idling and running. Next it the timing at W.O.T. the most you want on full throttle, then cruise timing that comes up whenever you stay at steady speeds to help milage. Now a fact I didnt know and need to check out on my car.I wont be able to till tommorow so I am curious if you other caddy people what you all will say. What is the cranking idle for engine when spinning over to start? Not starting just the rpm of the engine spinning before it starts? I found out that the holley sniper commands the crank timing to whatever you set it.I f you set it at 8 or 10 or 18* but after the engine exceeds 400 RPM it goes to idle timing which I set to 18* now this will kick the starter if it has more than 400 rpm before start.The starter sounds like it with no ignitian .When I check it out I will get back and say what I find. I'll unplug the fuel pump and watch the screen and see what it say the engine is cranking. I can also set the idle timing to 12 -15 and see if it fussess then. If this keeps up I'll be a Professor of Murhy's fun and antics before long. Maybe not any smarter but oh well if I can get whatever this dang car keeps hitting me with fixed.
I have an lt4 gm gear reduction starter on mine and it cranks about 225-275rpm with a fresh battery... If that helps
At that rpm it should't effect the switchover to idle timing at 18* The starter is the GM stylt at the moment.
Going to have to check my rpm's while cranking tommorow.
Well I got out and tested my new theory about the cranking That didnt come out as I was thinking. With the fuel pump unpluged the engine spins between 150 to 280. So thats short of 400. The starter I have on it now is a rebuilt gm full size starter.The highest timing I can go is 13* and still bucks a little. I set the idle timing to 13 also and made no difference.It still kicks at 8* a little. My battery is 1250 cranking amps. A little bit weak starter will also act like its too much timing. The dang kicking back only started with this starter, all the other spun overgreat till the too much clearance started killing the starters teeth. I can repair the hitachi gear starter and try again. I used the word starter and starting abunch on this post I know I know it's a pile right now Glad they started making more T.P.
P.S. got a new supply of beer and mixed drink fixioms
I finaly came to the conclusion that the timing was accurate and the problem was a starter that just wasn't up to par! I have gone thru a lot of starters.Most had low voltage due to
bad cable ends, and they were burning up in smoke. My gear reduction was working ok till the carb acted up and flooded the engine.I had put new plugs,oil and worked on the carb floodingand thought
that was fixed. When I went to start the engine at that time it once again flooded and the engine back fired while cranking and broke teeth off of the flywheel. I then replaced flywheel and started back with
starter problems.I rebuilt the gear reduction and its now working great. This time it was the flywheel being smaller than oem, not by much but I had to shave the mounting surface of the starter to
get correct clearance for the starter.The teeth had less than1/2 the teeth to engage way too far away. I'm going to start a new post about the flywheel.
I'm going to start on the cooling issue in a while.
I have not started on the cooling at this moment. The problem is I had to get a cup plug to seal the bypass! Something you would think is easy to find. NOPE I was online going thru the listings of the local part stores.You can not really find much unless you have a car to order it from. I'd put in 1 inch cup plug and block heater came up. then when they did come up somehow one inch translate
to packs for varius cars or singles of 1 1/2 larger. I do this so I can give them a part number ,as far as going to the stores you have to show a pic of what you need or they dont know what it is and of course what car is this on . A lot of trouble but I did finally find one but was too tired to do anything with it. I believe Murphy was riding with me yesterday
View attachment 25053
This is what you need to plug the bypass. Dorman 555-018 is the number of the cap plug. 1.01 (nom. 1")