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Shanto
Shant Yaz

(8 posts)

Registered:
09/30/2019 11:59PM

Main British Car:


Help with cooling system configuration
Posted by: Shanto
Date: October 15, 2019 01:56PM

Hello all,

I am a new member who is very glad to have found this forum as i was not able to get much help on the buick forums.

I have a 1962 volvo with a 215 conversion in it. i bought it after it had been sitting for 15 years.
I believe the engine was originally built by phil baker.
it is a sleeved (3.75") 215 block with 300 crank/heads/4barrel manifold.
i have rebuilt it and have gone through a whole lot of trouble reverse engineering what had been done to the engine. But, it is now together and in the vehicle.

i will try to give as much information as possible. if more is needed ill provide it to the best of my knowledge.

The original thermostat neck was corroded, and i adapted a sbf piece to it. the alignment isnt perfect, but it seemed to be fairly close.

The temperature sender is also in the thermostat neck, so it should be giving me the hottest (i think) reading of the engines coolant.

The stock coolant temp sensor port is plugged.

The bypass is connected to the water pump like stock.

Drilled a 1/8" hole at the 12 o'clock position of the thermostat. 180* murray thermo.

the radiator is 13"x 28"x 3". so it is quite large. when empty the cooling system takes almost 3 gallons.

The radiator is mounted lower than the engine, so it has no cap on it, only hose barb at the top to circulate water/air, back to the top of the expansion tank.

The expansion tank is mounted high on the firewall and has 3 ports.

The large bottom port is connected to the water pumps intake neck like stock.

the expansion tanks overflow/pressure port under the radiator cap is connected to the bottom of a recovery tank that should return coolant to the system when the coolant/temp drops.

the third port is at the top of the tank and recirculates the fluid from the top of the radiator.

The heater port in the back of the manifold is plugged.

The upper radiator hose is the serrated looking kind with a coil inside thats supposed to self vulcanize once you orient it. I am using the stock skylark accessories, so the upper hose has to make an arc over the valve cover and behind the alternator. that creates a high point in the system, and im sure the serrated parts help to trap air in them. :-(

unfortunately, there is not much room behind the radiator, so i am forced to run two slim puller fans in front. they do seem to work most of the time if it is getting warm in traffic, but not always.

I think that about covers it. now on to my issue.

I have noticed that the car seems to take a bit to warm up. and once warm sometimes will stay at 185-195 the entire drive. or it will continue to creep up and get up till 225-230 and i have to shut it down and wait for it to cool a bit. unfortunately because of this i have not had a chance to drive it for more than a 20 mile round trip yet, as i dont want to be left stranded.

once it reaches 200 ill switch the fan on and it usually will drop it back down to 185-190. but sometimes it doesnt and the temp will continue to creep and might go up to 220 before i shut it down to be safe. when i do this and leave the fan on while engine off it will cool off fairly quickly.

the hoses look ok, as in they have pressure and dont seem to be collapsed. sometimes the radiator feels very hot and sometimes it doesnt feel as hot as i think it should be at that certain coolant temp. so i am wondering if possible the system is causing hotspots/air and getting locked up. and thats why it sometimes drives fine and sometimes overheats. but it seems to want to overheat more than it seems to want to not. if i am doing city driving it seems i need the fans on all the time or else it will get hot. on the freeway it just hangs out at 185.

Basically it seems the coolant temperature always wants to creep and if nothing is done will overheat the engine 75% of the time.

My old machine shop instructor stopped by the other day and suggested two things.

1. due to the design of the internal coolant passages in the head/manifold, the blocked off heater port may be causing an air pocket to form in the manifold. and that i should tee it into the recirculation line from the top of the radiator to the top of the expansion tank. the problem is i am having a very hard time sourcing any sort of 5/8" to 5/16 or 1/4" reducer fittings.
i have a 3 way 5/8" tee that i can easily plumb it into the bottom line of the expansion tank. it would only be about a few inches from the tank, but it wouldnt be the high spot of the system. the air bubbles would have a short clear path to the expansion tank, but im not sure if doing that would defeat the purpose. i understand that this returned coolant will be bypassing the radiator, but not sure exactl what kind of impact that would have on the system.

2. the upper radiator hose that arcs over the valve cover could also trap air at the top of the arc and contribute a similar issue. he hated the idea of the corrugated hose and said i should be using two hoses with a union in between that has a 1/8" npt barbed fitting. and that i should also tee that into the line coming off the radiator to the top of the expansion tank. i do like his idea, but im kind of curious if three coolant sources will overwhelm the little 1/4" coolant return hose that i currently have running from the radiator to the expansion tank. im sure i could easily go to a 5/16" line, but i believe a 3/8" will be too large for both the radiator hose barb and the expansion tank hose barb.

one thing id like to also mention is that i am running an HEI from a '75 buick 350 on it.
as well as the stock spark plug i saw recommended for the 215 - NGK BP5HS
is this too hot of a plug? should i go one step colder?
what should the gap be set to with the HEI. i have them at .035" right now.
also, it might sound like a silly question, but i have no idea what to set the base timing to.
its a 215, that has basically been converted to a 300.
the 215 wants something really low like 5*. at this setting the engine shakes and sounds rough at idle.
300 calls for 8* i believe.
and the 350 calls for 12*.
obviously the more base timing i give it the more it smooths out and feels like it gives a stronger vacuum signal.
i set the timing to 8* with the vacuum advance disconnected and the port plugged. i have the vacuum advance to connected to manifold vaccum and with it connected will be around 32* at idle. i cant 100% confirm, but i believe that at 8* base timing, vacuum advance disconnected, i am getting around 36* total timing all in.
this seems fairly normal to me, but this is my first buick v8 and i dont really have much experience with these.

i have seen the power timing your buick thread, but i want to make sure that i can actually test the car at a consistent operating temperature before trying to power time it. just to eliminate as many variables as possible.

i will say, other than running hot, the motor sounds healthy. it revs smoothly and quickly and will set you back into your seat when you give it throttle. feels really quick in a 2400 lb car with 2.73 gears.

just curious if everything sounds correct to you guys.

sorry for the long post as i wanted to include as many pertinent details as i could.
i will also try to post some photos of the engine bay in case anyone has a hard time picturing how i have everything routed.


Shanto
Shant Yaz

(8 posts)

Registered:
09/30/2019 11:59PM

Main British Car:


Re: Help with cooling system configuration
Posted by: Shanto
Date: October 15, 2019 04:54PM

I had a chance to test the car a bit today and i believe ive noticed a pattern.

i should also mention that the radiator is a dual pass design with both ports on the passenger side.

i started the engine and it warmed up like normal. in about 7 minutes of idling it had reached 180 and stayed there.

i then began to drive the car. temperature stayed at 180 for about 20 minutes of street driving. it eventually started to go down and stayed at about 170 for about ten minutes before i returned home.

when i pulled into the lot, i let the engine idle for a bit as i checked over everything for any leaks.

a few minutes later i peaked inside at the gauge and it read 218.

turn the fans on and after 30 seconds or so, the temp starts dropping.

once it reached 200 i shut off the engine.

i then put my hand on the radiator and its ice cold. the coolant hoses however are fully pressurized and hot. but not that hot. i can grab them and hold them for about 5 seconds. theyre hot, but not like they should be at that temp. i was wearing nitrile gloves, but still.

at this same time, the engine/manifold/thermo housing is HOT.

when i run my hand across the radiator it is 90% cold except for the side the coolant ports are on. the end tank between them is hot. almost like there is no baffle between the "dual passes."

However, i have driven this car numerous times where the entire radiator gets up to temp as it should.

im really confused at this point and needed to walk away from the car as it started to frustrate me.

what could possibly cause this? i feel like i get all the air out of the system and then it goes and does something like this which seems exactly like air being trapped in the system.

the car is so fun to drive, but this conversion has been such a nightmare so far.


mgb260
Jim Nichols
Sequim,WA
(2019 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Help with cooling system configuration
Posted by: mgb260
Date: October 15, 2019 06:18PM

Shant, The small bypass hose is hooked up between intake and waterpump? You may have to put the front up on ramps and put a bleeder at high point. Open heater valve and fill completely to eliminate air.


Shanto
Shant Yaz

(8 posts)

Registered:
09/30/2019 11:59PM

Main British Car:


Re: Help with cooling system configuration
Posted by: Shanto
Date: October 15, 2019 06:53PM

yes, the bypass hose is connected like factory.

the car has no heater, so the rear port on the back of the manifold is capped.
normally the heater return is connected to the water pump inlet.
since i have no heater circuit, the bottom port on the expansion tank is connected to the water pump inlet.

i have attached a photo of my engine bay to better illustrate how my system is configured.

this was when the car was not finished, and i hadnt hooked up the hose to the recovery tank yet.

but you can see the high point that the upper radiator hose creates.

i am curious if blocking off the rear heater port is causing these issues since the coolant in the manifold is pooling there rather than circulating.

i have put the car on a ramp both front up and rear up and tried bleeding it quite a few times.

i feel like im chasing my tail since im getting funky inconsistent results.
volvo cooling system.jpeg


mgb260
Jim Nichols
Sequim,WA
(2019 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Help with cooling system configuration
Posted by: mgb260
Date: October 15, 2019 07:42PM

Make a loop with your heater hoses. try to get all the air out. it is hard with the radiator lower than the engine. Fans turning the right way?


40indianss
don foote

(61 posts)

Registered:
08/01/2013 04:35PM

Main British Car:


Re: Help with cooling system configuration
Posted by: 40indianss
Date: October 15, 2019 11:08PM

I would try to install an aluminum tube with a bleeder valve over the valve cover or a rad pressure cap at that location to use as the primary coolant fill location


minorv8
Jukka Harkola

(186 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Help with cooling system configuration
Posted by: minorv8
Date: October 16, 2019 12:27AM

This sounds familiar as I also have a similar upper hose setup. I have a nipple on the highest point of upper hose / pipe setup. That bleeds any trapped air to the expansion tank. It definitely needs that, otherwise it will overheat pretty fast.

Radiator hoses.jpg

Also, you mentioned puller fans. Since these are in front of radiator should the not be pusher type fans ? Whatever the name, make sure that they actually push the air thru the radiator and not pull the from engine compartment.



Shanto
Shant Yaz

(8 posts)

Registered:
09/30/2019 11:59PM

Main British Car:


Re: Help with cooling system configuration
Posted by: Shanto
Date: October 16, 2019 12:17PM

thank you guys for the suggestions. they seem in line with what i was thinking would be the next step.

i did make a mistake and call them puller fans. they are actually wired to push air through the radiator, so yes, pusher fans.

unfortunately, i believe the engine has a cracked sleeve/block.
i pulled the #1 spark plug yesterday and turned the engine over and it shot out like a geyser. yippee.
the reason the radiator was cold was because there was no coolant in it.

i could give my explanation as to why i believe its a cracked block and not a head or gasket sealing issue if anyones interested. but at this point, i believe that to be the case.

when i bought the car the engine was seized and as part of the deal the previous owner gave me a fresh rebuilt 4.6.
he said he bought the engine because he heard it was a direct replacement, but found out about all the small differences and it was over his head to make the conversion.

so i do have a fresh 4.6. i also have a 450 whp ls1 that i removed from my camaro.

i have heard that i need a lot of new parts to make the rover work in my carbureted application.
i also know that it will require a lot of fabrication work to fit the ls1. especially due to the steering box location.

i will make another thread about that topic.

a little frustrated about the whole situation, but it is what it is.


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