All Small Six Snowcat with a Six - Getting a 1968 Thiokol Spryte up to Speed!

[CHCzecora]

Cooling Fans:
@TrickSix - After getting up in the space, it is pretty minimal there and I'm hesitant to go mechanical now (also taking note of @63 Sprint's note on potentially too much cooling in the deep cold). Another snowcatter mentioned double fans - adding a push fan. I'd like y'alls take on this, but it seems like it could be a fairly easy add on the outside of the radiator (@sixtseventwo4d would this need shrouding?). Max of 15 MPH doesn't bring in much air!

Pulled off the grill, here is the radiator:



Alternators:
@Frank - Thanks for the upvote on the 1-wire. I will reconsider! @sixtseventwo4d good call on checking/going with the bigger wire gauge.

Carburetor:
Seems like the consensus is stick with what I got. @Frank your reasoning sounds legit "low end and moderate rpm" is the overall use case.

RPMs:
@drag-200stang @DON - I'll have to look into this. Not sure how reliable or functional my instrumentation is at this point.

Timing Chain:
@63 Sprint - I wonder if this is a thing for this year... worth pursuing when I have the radiator off?

 

[Frank]

Cooling Fans:
@TrickSix - After getting up in the space, it is pretty minimal there and I'm hesitant to go mechanical now (also taking note of @63 Sprint's note on potentially too much cooling in the deep cold). Another snowcatter mentioned double fans - adding a push fan. I'd like y'alls take on this, but it seems like it could be a fairly easy add on the outside of the radiator (@sixtseventwo4d would this need shrouding?). Max of 15 MPH doesn't bring in much air!

Pulled off the grill, here is the radiator:

View attachment 23122

Alternators:
@Frank - Thanks for the upvote on the 1-wire. I will reconsider! @sixtseventwo4d good call on checking/going with the bigger wire gauge.

Carburetor:
Seems like the consensus is stick with what I got. @Frank your reasoning sounds legit "low end and moderate rpm" is the overall use case.

RPMs:
@drag-200stang @DON - I'll have to look into this. Not sure how reliable or functional my instrumentation is at this point.

Timing Chain:
@63 Sprint - I wonder if this is a thing for this year... worth pursuing when I have the radiator off?

I've read that a pusher electric fan is more effective than if it's set up to pull. I had a puller & pusher on the same radiator for a few seasons, it worked well. Not sure how large your current electric fan is. Adding a 12" or so pusher mounted so it's offset from the puller fan, IE: covers an area of the rad that the current fan doesn't cover, would probably do the trick. The electrics have the shroud built in. Only need a shroud with a mechanical.

The engine shouldn't be hard to keep cool in that environment, with a modest airflow. That's plenty of radiator for the small 6. Still recommend changing the thermostat.

 

[sixtseventwo4d]

The shroud I am making mention of would go on the inside to help a manual fan pull the most through the radiator. (if you decide to go that direction.) Shrouds are most needed for slow-speed operation.
In your cold climate, you would also need a clutch on the fan otherwise the radiator may not ever warm up; something you want to happen since a constant inrush of cold coolant does not help the engine wear or cab heat.
It may work better for you to stick with electric fans. and have them thermostatically controlled.

 

[63 Sprint]

CHCzcora,
Were you able to do a compression test on all cylinders?

The best way to take readings:
• Carburetor fully opened (full throttle)
• All spark plugs removed so engine spins freely.
• Coil wire removed from coil and distributor.

Tip: It would be easier to number all the spark plug wires for each cylinder and then remove the distributor cap with all the wires attached to the cap. This way it will be easier to get all the wires on to the proper cylinders when finished with the test.

A compression test will help give us more information on the condition of the engine. And, will also give valuable information to know what the cranking compression numbers are at higher elevations.

 

[TrickSix]

^^^ Keep the spark plugs in order and take pictures of the business end while they're out. How they look can tell you a lot about the health of the engine too.

 

[CHCzecora]

@Frank, @sixtseventwo4d - Y'all are confirming my gut with an electric pusher fan addition. It seems like this will be the ideal setup at this point. The existing custom fabrication is actually pretty well done, so I won't mess with it beyond the potential addition.

@63 Sprint, @TrickSix - Thanks for the compression testing advise, I'll have to dig into it over the weekend and get back here to report!

Super appreciative of everyone's support here!

 

[Bronctopia]

I suspect a pusher fan may be more vulnerable to snow/ice blockage. Possibly conifer impingement.
Modern vehicles use typically 2 puller fans in a rectangular "shroud" arrangement, and with modern tight engine bays they are typically pretty low profile.
Your radiator looks a lot taller, so I would take some measurements and go junkyard browsing for maybe 2 econo car fan shrouds to stack.

 

[CHCzecora]

Compression Test reporting:



Tested each cylinder 3 times (boxed in red) for an average PSI:

Cylinder	PSI	Percentage Difference
1	127	0% (Reference)
2	112	11.81%
3	120	5.51%
4	125	1.57%
5	123	3.15%
6	120	5.51%

Notes:

• Keep in mind I'm at 4,650 ft (and will operate it at 7-10k)
• Highest reading (Cylinder 1 at 127 PSI) and the lowest reading (Cylinder 2 at 112 PSI) have a difference of about 12%
• Performed a "wet test" on Cylinder 2 and things jumped to an average of 173 PSI (sign of worn piston rings?)
• I ran through the lineup again once each and all readings jumped up (marked in blue). What is up with that?

So... what is y'all's verdict?

 

[aussie7mains]

Compression Test reporting:

View attachment 23153

Tested each cylinder 3 times (boxed in red) for an average PSI:

Cylinder	PSI	Percentage Difference
1	127	0% (Reference)
2	112	11.81%
3	120	5.51%
4	125	1.57%
5	123	3.15%
6	120	5.51%

Notes:

• Keep in mind I'm at 4,650 ft (and will operate it at 7-10k)
• Highest reading (Cylinder 1 at 127 PSI) and the lowest reading (Cylinder 2 at 112 PSI) have a difference of about 12%
• Performed a "wet test" on Cylinder 2 and things jumped to an average of 173 PSI (sign of worn piston rings?)
• I ran through the lineup again once each and all readings jumped up (marked in blue). What is up with that?

So... what is y'all's verdict?

All good.

 

[B RON CO]

Hi, while we would hope for our compression test numbers to be a few points higher, I would tune it up and run it. The engine has some wear, and you don't know it's long history. This winter, if it was mine, I would have fun, and check the oil before each use. On many older engines, excess blue smoke is the bad sign. To me, the plugs look pretty normal. What plugs do you have, what plugs are you planning to go with? I like the Autolite ASP46 plugs. Maybe down the trail, It will be time to think about rings and bearings, or a complete rebuild, along with a valve job. Good luck

 

[Frank]

I agree, tune it up use good oil and enjoy. If you're handy with carbs, a smaller jet would be beneficial. At 4700 feet it's 14% too rich and at 10,000' it's 30% too rich compared to a standard low-altitude tune. Some of the plugs don't look too bad, so it's already jetted down some it appears.
That tiny open aircleaner is not doing you any favors. If you can get your hands on any factory type enclosed filter housing it would be an improvement, especially if it has the snorkel with the hot-air valve in it. Heating the intake air will help everything, especially cold engine manners.

 

[pmuller9]

I don’t understand how the previous posts can suggest that the spark plugs look ok.
Those are some of the worst oil fouled plugs I have seen in a long time.
It could be piston rings or intake valve stem seals.

The compression readings can be increased by squirting oil in the cylinders because of a little better cylinder seal but also the oil sitting in the piston dish increases the compression ratio.

You also need to check how many degrees you can turn the crankshaft back and forth before the distributor rotor moves.
This will indicate how bad the timing chain is.

 

[63 Sprint]

You also need to check how many degrees you can turn the crankshaft back and forth before the distributor rotor moves.
This will indicate how bad the timing chain is.

From what I’ve experienced with the 170 and 200 engines. There could be 13 degrees or more of back and forth crankshaft movement before the distributor shaft start's moving.

 

[Frank]

I don’t understand how the previous posts can suggest that the spark plugs look ok.
Those are some of the worst oil fouled plugs I have seen in a long time.
It could be piston rings or intake valve stem seals.

The compression readings can be increased by squirting oil in the cylinders because of a little better cylinder seal but also the oil sitting in the piston dish increases the compression ratio.

You also need to check how many degrees you can turn the crankshaft back and forth before the distributor rotor moves.
This will indicate how bad the timing chain is.

They look terrible. The porcelain on #3 and to a lesser * #5 are clean enough to indicate my opinion of burn temp/ fuel mix, the oil was not being addressed.

 

[CHCzecora]

@B RON CO - thanks for the plug recommendation, just bought ‘em
@Frank -
- “Handy with the carbs”?! Smaller jet? I thought it was earlier stated that the Carter YF was all good.
- Factory enclosed air cleaner, snorkel with a hot air valve? Any chance there is a modern, more accessible (quick purchase online) approach?
- Sounds like this is addressing the whole assembly. I think the existing setup is attempting to conform to the “doghouse” but I’m not married to it and am willing to fabricate a new one (this can help me address my noise issue as well as I can add more insulation)
@pmuller9 -
- New plugs are on the way, but the solution is basically a future rebuild… right? Or is there something more approachable that I should shoot for this year?
- Do the cylinder oil squirts last? Seasonal or other frequency?

Clueless Queues:
Crankshaft turn testing (Distributor rotation):
- Is the purpose just to assess the timing chain? If bad, does this mean a rebuild or is it just getting out in front of it?

As for tuning… I’m clueless here. I’ll research, but any guidance would be appreciated!

 

[63 Sprint]

Clueless Queues:
Crankshaft turn testing (Distributor rotation):
- Is the purpose just to assess the timing chain? If bad, does this mean a rebuild or is it just getting out in front of it?

The purpose of the test is to see how badly the timing chain and sprocket's are worn.
I believe that if they have not been replaced once before, they are most likely going to need replacing. It's a fairly common problem with the small block six. If you’re fairly decent in mechanics, it’s not too hard of a project. The front pulley and damper will need to come off the crankshaft. A puller will most likely be needed. They can be borrowed at AutoZone. If my remember correctly, a new oil pan gasket, timing cover gasket and crank seal should be installed when a new timing chain and sprockets are installed.

Here is a picture of the timing cover:

I’ve done it on one engine without replacing any gaskets and crank seal. It leaked some but not to bad. I was lucky. The other engines needed new gaskets and crank seal.

As for tuning… I’m clueless here. I’ll research, but any guidance would be appreciated!

I think I mentioned earlier that in order to tune the carb correctly, an AFR meter and vacuum gauge is recommended.

 

[pmuller9]

- New plugs are on the way, but the solution is basically a future rebuild… right? Or is there something more approachable that I should shoot for this year?
- Do the cylinder oil squirts last? Seasonal or other frequency?

Yes, the solution is a rebuild in the near future.
At that time you may want to consider raising the compression to make up for some of the power loss due to the elevation.
At 10k ft of elevation the engine is down 30% in power compared to sea level.

The cylinder oil squirts will be gone next time you run the engine.

 

[sixtseventwo4d]

As for tuning… I’m clueless here. I’ll research, but any guidance would be appreciated!

Don't get disheartened. It may not be as bad as the plugs look at the present. Do the timing chain check, as it effects both engine (cam) and ignition timing.
An engine that doesn't get started and ran regularly at operating temperature for a good period of time can really foul up the plugs. It also helps to keep the rings freed up on the pistons. If the rings get a lot of carbon between them and the piston they can become sticky. Squirt about two tablespoons of ATF or Marvel oil in each cylinder while you have the plugs out. Allow a few days or more for it to wick around the rings. Turn the engine over by hand once a day to help the process along; but not if you have the timing chain off!!
As previously mentioned, it may be valve guide seals allowing oil to get into the cylinders. Those seals (inexpensive) can be replaced with the engine left in place and the head still on if you have the patience and are careful enough.
I would clean up the old plugs and use them initially after doing all the engine work since there will be some oil to burn out of the cylinder. Do another compression check after you have run the engine a couple of times under a load and do it with the engine still warm. Have a battery charger on it when doing your compression tests. It can help with consistency and makes it easier on the starter
A cylinder leak-down tester will help you discover if you actually have valve or ring problems. They are not expensive if you shop around for one.

 

[hodaka100]

I would put liquid Seafoam in each spark plug hole, let soak, turn the crank by hand, reapply and do for several hours. Then put new plugs in, start it and warm it up. Now put "gm top engine cleaner" in a vacuum hose as per the directions or use Seafoam.
Maybe it would be better to do the solvent in the intake first and Seafoam the cylinders after or just do the cylinders before and after the intake. Anyway, after both are done, run it/ use the vehicle for a while and recheck the compression and spark plugs. Also change the oil after the top end flushes and put a quart of rislone or atf in as one of the quarts of oil.

 

[TrickSix]

As has already been mentioned, that tiny air filter is very restrictive and should be replaced. However, the high-mounted choke housing on that Carter carb means that a lot of common Ford six-cylinder air cleaner bottoms won't fit. There needs to be a big "dent" in the air cleaner base to clear the choke housing. I'm not suggesting you buy this eBay item, I'm not positive it's the right one and there's no top for it either. But the picture clearly shows the bottom bulge needed to clear the choke and let the air cleaner sit on and seal to the carb inlet. I'm not familiar with the Carter carbs, others on here should know all about them and the air cleaners that work.
https://www.ebay.com/itm/3755238840...uid=yPAA4oA3Qxu&widget_ver=artemis&media=COPY
And here's a different kind of air cleaner assembly that may work, but again, this is just food for thought at this point... Let's hear from the pros.
https://www.ebay.com/itm/2668367417...uid=yPAA4oA3Qxu&widget_ver=artemis&media=COPY
Another possible air cleaner family that would work are the ones fitted to 1960s Ford engines with the 1101 carburetor. Those have a fairly high mounted choke too, and air cleaners with a bump in the bottom.