V4 1987 Looper Low Compression & Backfire In One Cylinder

[Riley C]

Here are the plugs now after the thermo install.

 

[Bosunsmate]

Bos,

I just uploaded some pics. See what you think.

Can I just leave the thermos in for now???

Yep definitely leave them in, you a getting better restriction with them due to seeing that telltale pressure up more and you havent seen the temperature get into the too hot zone.
I dont know enough about that system to comment on what you could do to bypass a removed control module.
On mine and most others ive worked on the thermostat opens when temperature gets hot at low rpm. When rpm increase the extra water puts more pressure on the system and lifts open poppet valves or pushes the whole thermostat housing back off its seat and water then can gush around it and flood lots of volume through the system.
On yours there looks to meant to be a valve connected to your throttle plate that must change the routing of water there as FBullet says allowing the thermost to lift off. I really dont know why they complicated it with that and didnt just use the spring system other motors have.

 

[Bosunsmate]

Sparks look good by the way.
I still dont get the high idle rpm of 900. I wonder if she is still running slightly cold at idle due to the water set up this last owner genius did to it. Perhaps in this current set up its making the thermostats be unseated due to no pressure coming on them from the control line by the impeller. Problem is if you keep them in they wont let enough water in at higher rpm and ive no idea what grade spring would work to keep them seated at idle and rise off as rpm increases.
But im sure theres a way to find out
If she was still running cold from unseated thermos that could explain the knock in your low range too as you powered up while cool

 

[Riley C]

Yep definitely leave them in, you a getting better restriction with them due to seeing that telltale pressure up more and you havent seen the temperature get into the too hot zone.
I dont know enough about that system to comment on what you could do to bypass a removed control module.
On mine and most others ive worked on the thermostat opens when temperature gets hot at low rpm. When rpm increase the extra water puts more pressure on the system and lifts open poppet valves or pushes the whole thermostat housing back off its seat and water then can gush around it and flood lots of volume through the system.
On yours there looks to meant to be a valve connected to your throttle plate that must change the routing of water there as FBullet says allowing the thermost to lift off. I really dont know why they complicated it with that and didnt just use the spring system other motors have.

Thanks Bos.

Hopefully I can source a control valve. I know it wasn't the previous owner, as he was such a nice old dude. So can't be pissed at him.

ill try it on the water tomorrow.

 

[Bosunsmate]

Thanks Bos.

Hopefully I can source a control valve. I know it wasn't the previous owner, as he was such a nice old dude. So can't be pissed at him.

ill try it on the water tomorrow.

Haha dont be so sure. I bought my first car, a datsun 140J off an old nice dude and when my mate was hurrying me up he play kicked my car. He ended up putting his foot right through the door sump, the nice old guy had bogged and rebuilt my car using a Fosters beer cardboard pack.

Id look at using springs myself if it was urgent. But hopefully you can find a wreckers open now its NYday plus 2

 

[Faztbullet]

Has to have water control valve to operate correctly and live. These are the small bore loopers and have bridged exhaust. Running to hot causes bridge to expand and scuff the exhaust side of piston. If you cant find a valve just update it to the 3 cylinder 70hp style cooling, not cheap but works great.

 

[Riley C]

OK sounds like I need to take thermos out until I can source a valve. Ill be uploading a video shortly of the idle. I couldn't take the cover off with the family on the boat. Ill do another video if needed.

 

[Riley C]

I seriously cant find a valve anywhere, it's discontinued. What will I do????

There are no replacement parts.

 

[Riley C]

Sparks look good by the way.
I still dont get the high idle rpm of 900. I wonder if she is still running slightly cold at idle due to the water set up this last owner genius did to it. Perhaps in this current set up its making the thermostats be unseated due to no pressure coming on them from the control line by the impeller. Problem is if you keep them in they wont let enough water in at higher rpm and ive no idea what grade spring would work to keep them seated at idle and rise off as rpm increases.
But im sure theres a way to find out
If she was still running cold from unseated thermos that could explain the knock in your low range too as you powered up while cool

Hi Bos,

See idle video attached of startup. It was the best I could give today.

I did notice tell tale dropped alot in pressure today compared to the first run. I think the stats are blocking the head off now, but the temp didnt go up... I think I need to pull them out until I sort the valve out. What do you think think?

https://www.dropbox.com/s/cd4sikba7udgwz7/IMG_4802.MOV?dl=0

 

[upallnight1960]

What type of file did you use to upload your pics? ALL I get is error.

 

[Riley C]

What type of file did you use to upload your pics? ALL I get is error.

Just a movie file I uploaded to Dropbox.

 

[Bosunsmate]

What type of file did you use to upload your pics? ALL I get is error.

Video works, just hit the X if you dont have a dropbox account like i dont

 

[Bosunsmate]

Hi Bos,

See idle video attached of startup. It was the best I could give today.

I did notice tell tale dropped alot in pressure today compared to the first run. I think the stats are blocking the head off now, but the temp didnt go up... I think I need to pull them out until I sort the valve out. What do you think think?

https://www.dropbox.com/s/cd4sikba7udgwz7/IMG_4802.MOV?dl=0

Seems to idle ok just a bit high in my opinion.
I think you should ask FBullet about his post that says this, just dont let your missus see it " If you cant find a valve just update it to the 3 cylinder 70hp style cooling, not cheap but works great."
As for the tough question of keeping them in or out id say they are probably not doing much in there at present and a just lifting straight off so if you are more comfortable with them out take them out.
Ive a two cylinder cooling at the moment and a four cylinder so i cant comment on the three cylinder cooling.
Have you tried ringing outboard wreckers over there for the valve, we have quite a few wreckers here and quite often on the internet i see parts listed from Australian Wreckers

 

[Bosunsmate]

Theres a few of them listed on the internet second hand, just put in the code for its part# and they turn up. They seem to be in USA so postage may take a few days. You will also need to check you dont need anything else for that system.
From what FBullet said it seems that there is pressure provided directly to that Control valve via the impeller.
That implies there must be some bypassing nipple/connection somewhere on the LU waterpump housing or further up the chain.
You better check that you have that facility on your motor before buying a control valve that cant be plugged into anything.
You never know if someone has put a different LU on and that didnt have the connection and thus they removed the control valve.
Never fear if that is the case you should still be able to do the 3 cylinder hp style cooling
Also if the pressure to the control valve does come from the LU there would need to be a hose routed up through the midsection which may be a tricky undertaking if its not currently in situ.
On the good news it looks like you still have it teed of with the proper telltale T splitter connector

 

[Riley C]

Hi Bos,

Mate really appreciate you helping me out. I should also say that the thermos I got were the 0434137 - Thermostat, 140 Degrees model, and not the old style. Would this change anything.

I have read a little in this forum on the Dhadley and what he suggests???

 

[Riley C]

Ok,

So because I have the white stats I cant do anything but use a control valve, is this correct? Fatz I assume I need to get additional piping too, as it's a three way valve.

 

[Bosunsmate]

Hi Bos,

Mate really appreciate you helping me out. I should also say that the thermos I got were the 0434137 - Thermostat, 140 Degrees model, and not the old style. Would this change anything.

I have read a little in this forum on the Dhadley and what he suggests???

I suspect you need the right ones for that motor and either would require the control valve too.
Post a link to what Dhadley has written if you still want to do what he/she says.
I think you need to find out whats needed for the 3 cylinder conversion and if you go ahead with the control valve you will need to find out where the impeller pressure comes from to plug into the control valve as im surprised if you have done the impeller that you didnt see something down there then. Check out if you order a control valve that it comes with the little metal bit that joins onto the timing plate thing, although you could probably fashion one if necessary.
Chin up, im on my third puncture in three days on gravel roads here and am now out of puncture patches, you will get her running just right soon enough

 

[Riley C]

Hi BOS

Not really sure what you mean by link to timing etc.When I pulled down the kit, I replaced exactly the kit. Didn’t see much other than the normal gear link and drive shaft. Can number what you mean below?

 

[Riley C]

I suspect you need the right ones for that motor and either would require the control valve too.
Post a link to what Dhadley has written if you still want to do what he/she says.
I think you need to find out whats needed for the 3 cylinder conversion and if you go ahead with the control valve you will need to find out where the impeller pressure comes from to plug into the control valve as im surprised if you have done the impeller that you didnt see something down there then. Check out if you order a control valve that it comes with the little metal bit that joins onto the timing plate thing, although you could probably fashion one if necessary.
Chin up, im on my third puncture in three days on gravel roads here and am now out of puncture patches, you will get her running just right soon enough

I might be inluck with a wrecker in Fraser area.

Further see photo showing a hose from the body, is that you were talking about from the impeller Bos?

 

[Bosunsmate]

Hi BOS

Not really sure what you mean by link to timing etc.When I pulled down the kit, I replaced exactly the kit. Didn’t see much other than the normal gear link and drive shaft. Can number what you mean below?

I wasnt clear writing that, thats for sure. What i meant is that most of those control valves for sale have no arm on them to connect to the cam throttle lever (which i think you have inverted due to it being worn.....).
I saw one control valve advertised that did have this insert piece of metal, its a little piece of metal with an eye on one end which must connect to your throttle lever. I just thought you better be aware of that fishhook.