Importance of engine shields?

Mr.DNA · Post by **Mr.DNA** » Sat Jun 24, 2017 10:34 am

Hi all,

I'm new to the forum and new to Rampside ownership. I'm also no engineer, but it seems to me like an air-cooled engine was probably designed with specific airflow paths in mind. My truck is missing the front and both side engine shields. Additionally, the previous owner put a single center-mounted carb on the engine, which does not fit in the Rampside engine compartment, so the stock cover has also been removed and a wooden box was built to sit over the engine, effectively leaving the engine completely open on both the top and the bottom sides. I live in the UP of Michigan and have not yet faced any temperatures over 75°F and the truck seems to be running okay so far, but I can't help but think it could be running better with proper air flow. Maybe not, though? How big of a deal are the engine shields?

Post by **66vairguy** » Sat Jun 24, 2017 12:41 pm

Your intuition on air flow is correct. GM would certainly not waste a penny for something if it was not needed.

That said a lot of folks claim you don't need the shrouds because they don't use them and it works fine - (until it doesn't of course).

The Corvair cooling system was tested out at the Western Proving Grounds in extreme heat, so yes you can get by with air gaps at lower temps if you are not going up a long climb or hauling a load. The point of the shrouds was to keep the low pressure area on top of the engine from sucking hot air up from below the engine. The "engine tin" shrouds are out there, check vendors, etc. Some of the sealing is a flexible material, Clark's and others have kits.

The center mount carburetor is attractive because it's simpler than dealing with two carburetors. However those long runners are not heated (like in an old VW) so fuel at idle tends to "drop out" before it gets to the heads. Great on a dune buggy going wide open all the time, not good for normal driving.

Balancing two carburetors really isn't hard once you learn and is something that rarely needs to be done once set up correctly. Usually folks check the carburetor balance during a tune-up. If you ever go back to two carbs you'll also need the balance tube and the PCV plumbing. I see you crankcase just has a single air filter on the vent.

skipvair · Post by **skipvair** » Sat Jun 24, 2017 4:14 pm

I would at least get the seal that goes around the dipstick tube until u get all the shrouding

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toytron · Post by **toytron** » Sat Jun 24, 2017 5:14 pm

Yes and if you go back to two carbs then you can get rid of the pallet and put a proper deck in your bed.

Ed Stevenson

Mr.DNA · Post by **Mr.DNA** » Sun Jun 25, 2017 8:27 am

Thanks for all the feedback. Follow up question: I do have the original (or maybe an original) engine compartment cover/deck, and I would like to convert back to the dual carb setup. At that point when the top side of the engine is all closed up, will the missing shields become a bigger issue? Should I wait to switch the carbs until I also have the shields?

Also, a quick search for engine shields for sale doesn't turn any up. Any ideas where I might find some? I'm using the term "engine shield" because that is what the shop manual calls them on page 57 (http://www.corvair.org/chapters/corvana ... =Corvair95), but maybe they're more commonly referred to by another name?

toytron · Post by **toytron** » Sun Jun 25, 2017 8:42 am

Many refer to them as tins. Maybe Brad can provide a break down that would give you an idea what is suppose to be there and then you could know what you need. (Brad is our local information guru and all around technical librarian :).

Ed Stevenson

Post by **bbodie52** » Sun Jun 25, 2017 8:56 am

Welcome to the Corvair Forum!

I think your idea of returning to the original engine compartment configuration would be a wise choice — especially considering your location in northern Michigan. The center mounted carburetor modification tends to be "cold-blooded", because it lacks engine heat. But if you do seal up the engine compartment, it should be sealed completely to prevent the heated air that is exhausted by the cooling system from recycling back into the engine compartment. Your engine appears to be a 1965 or later 164 CI engine (possibly rated at 110 hp). The picture shows a magnesium cooling fan that was originally fitted only to 1964 and later engines. The engine is also fitted with an alternator, that was introduced to Corvairs in 1965. Of course both upgrades can be bolted onto earlier engines. Other clues might be the engine serial number that is stamped on the engine cases near the alternator (next to the sheet metal shroud). The cylinder head casting numbers can be found on the end of each head. The early Corvair engines had a crankshaft pulley that is made from stamped steel components and was riveted together. In 1964 the increased engine displacement to 164 CI was accomplished with a long stroke crankshaft. This change prompted engineers to replace the standard pulley with a harmonic balancer to help protect the crankshaft. The harmonic balancer was utilized on all 110 hp, 140 hp, and turbocharged engines. Only the 95 hp engine received a solid cast crankshaft pulley. The pulleys are interchangeable bolt on items, but the one on your engine could provide a further clue as to the nature of the engine.

The attached publication, CORSA Corvair Technical Guide 1+2 - Corvair Code Numbers, with help you to identify your engine. The attachment provides a breakdown of cylinder head casting numbers and engine serial numbers.

CORSA Corvair Technical Guide 1+2 - Corvair Code Numbers.PDF: CORSA Corvair Technical Guide 1+2 - Corvair Code Numbers; (1.25 MiB) Downloaded 16 times

The link below will provide you with a list of useful websites that are Corvair-related. Some of the links will lead you to an extensive technical library that will allow you to download shop manuals and other technical references in Adobe Reader format at no cost. There is also a link that will help you to locate nearby CORSA (Corvair Society of America) club chapters. While the Corvair Forum can be very helpful as you work on your Corvair, having local friends and contacts in your region who are knowledgeable about the Corvair can also be very helpful. These family-friendly CORSA chapters often offer picnics, group scenic drives, technical training and assistance, car shows, and competition events that can greatly enhance your enjoyment of Corvair ownership. You will also find a list of essential Corvair parts suppliers. Clark's Corvair Parts is the biggest and oldest Corvair supplier in the world. You will find a link that can provide you with a series of videos that amount to a tour of the Clark's Corvair Parts facilities. I think you will be amazed at the quality of the reproduction components they offer — particularly the interior carpeting and re-upholstery items. Parts suppliers such as this truly make our Corvair hobby possible.

Common and Useful Corvair Websites

http://www.corvairforum.com/forum/viewt ... 225&t=6007

In particular the Corvair Ranch in Pennsylvania has a large inventory of used Corvair parts. I would recommend downloading and reviewing a Corvair shop manual engine section that includes an illustrated parts breakdown of the sheet metal shrouds and other components that surround the engine. There may be some unique configurations that match the Corvair truck and van engine compartment. If you provide them with the model year of your Corvair truck and identify the engine that is currently installed in it, the staff at the Corvair Ranch should be able to fill the list of sheet metal components that you will need to seal your engine compartment. You may also need additional carburetor components to make the conversion back to two Rochester HV carburetors. Your Positive Crankcase Ventilation (PCV) system is incomplete. You will also likely need missing choke linkage and throttle linkage components, and the vacuum balance tube to connect between the two cylinder head intake manifolds. Study the shop manual illustrations and compare them with the current engine configuration in your truck. If you talk to a Corvair Ranch representative, try to describe to them what you currently have, and what you are trying to accomplish. Their experience with Corvairs should make it easy for them to assist you with developing a full list of materials that you will need to restore the original engine configuration. A comprehensive list should help you to order everything you need to have it shipped in a single shipment, which will not only save money, but save frustration with missing items as well.

If your truck is not configured with a heater and defroster, or if some of those components are missing the may want to consider restoring a serviceable heater and defroster system to your truck, so the driving in the Michigan winters will be a possibility.

Corvair Ranch (New and Used Parts, Machine Shop, etc.)

http://www.corvairranch.com/

Post by **66vairguy** » Sun Jun 25, 2017 3:31 pm

Mr. DNA - maybe I missed it - but what is your location? That would help with possible engine tin finds.

BTW - the carbs have to be off to easily remove the top fan shroud - something you should do when convenient (you'd be amazed what collects there on top of the engine cooling fins).

I would suggest finding a Corvair buddy who can help. You've got some work ahead to get it back to dual carb setup that allows the original engine cover to be installed. A knowledgeable person will make things go much better.

Post by **bbodie52** » Sun Jun 25, 2017 6:02 pm

Mr.DNA wrote:Sat Jun 24, 2017 12:34 pm

...I live in the UP [Upper Peninsula] of Michigan...

Upper Peninsula of Michigan, Michigan

Post by **66vairguy** » Mon Jun 26, 2017 12:29 pm

The closest to you is Corvair Ranch. I've never dealt with the Corvair Ranch, but folks speak well of them - http://www.corvairranch.com/

Clark's used parts supply seems to be shrinking. Jeff at Calif. Corvair has used spares. Davemotohead on the other forum sell a lot of sheet metal parts.

Just be aware that engine "tin" varies a lot from badly corroded to very good - ASK what the condition is as "USED" means little.

Post by **bbodie52** » Mon Jun 26, 2017 1:22 pm

This is a good website for information for any Corvair van or truck owner...

https://www.corvair.org/chapters/corvanatics/

Left-click each image to enlarge for better viewing...

: Corvair Engine Sheet Metal - Exploded View (1964)

: Corvair Engine Sheet Metal - Exploded View (1965)

: 1961-1964 FC Bodyside Sheet Metal

toytron · Post by **toytron** » Tue Jun 27, 2017 6:25 am

See I told you Brad would come through for you! You rock Brad!

Ed Stevenson

lostboy · Post by **lostboy** » Tue Jun 27, 2017 7:03 am

The only shroud I am missing is 19 and I have had no issues driving my sedan in the dead heat of summer in NJ. Even in heavy traffic.

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Mr.DNA · Post by **Mr.DNA** » Tue Jun 27, 2017 12:03 pm

Your engine appears to be a 1965 or later 164 CI engine (possibly rated at 110 hp)

I believe it is a 1964 110hp engine. Engine number is T0207YN and head number is 3819876. The generator was swapped out for the alternator by the last owner, I was told.

You may also need additional carburetor components to make the conversion back to two Rochester HV carburetors.

Full disclosure: I am new to Rampside ownership, but I drove a 62 500 coupe almost daily for several years around Phoenix, AZ, in the early 2000s. It is currently parked in my dad's shop in Oregon, where it has been since ~2006. I was in Oregon visiting a couple of weeks ago and dropped in on Lon at Corvair Underground. He is the one who basically convinced me to revert back to the dual carb configuration (it wasn't until I got back to the shop and was looking over the 500 engine compartment and how completely sealed up it is that I realized the tins were missing from my truck). I was hoping to pull the carbs off of that engine (also a 64 110hp), but there are two issues with that: first it doesn't look like the 500 compartment will have enough clearance for the single manifold/carb/air cleaner that I currently have on the truck, so making that swap won't be so simple; second the 500 currently has the single center air cleaner, which the truck won't have clearance for, meaning I'll have to find a pair of the tuck-behind air cleaners.

I would suggest finding a Corvair buddy who can help. You've got some work ahead to get it back to dual carb setup that allows the original engine cover to be installed. A knowledgeable person will make things go much better.

The good news is that even if I don't swap anything off of the 500, at least I'll have a working dual-carb system to refer to when I have questions (albeit several states away).

maybe I missed it - but what is your location?

I'm just about dead center in the map that was posted. Marquette, Michigan. Looks like at least 4 hours from the nearest CORSA chapter. Also, I registered with Corvanatics the day after I came home with the truck! Thanks again for all the tips! I'll be giving Corvair Ranch a call.

Post by **bbodie52** » Tue Jun 27, 2017 5:58 pm

T0207YN

T = Tonawanda, New York (GM Tonawanda Engine Plant)
http://media.gm.com/media/us/en/gm/comp ... wanda.html
0207 = Engine manufacturing date (month and date). February 7th.
YN = 1964 - 110 HP, 164 CID, Manual Transmission (500/700/900 Monza)
YN = 1962-1963 - 102 HP, 145 CID, Manual Transmission (500/700/900 Monza, except Station Wagon)
YN = 1961 - 98 HP, 145 CID, 9:1 CR, Manual Transmission (500/700/900 Monza, except Station Wagon)

Cylinder Head No: 3819876, 9.25:1 CR, 164 CID, 110 hp, 1964, 3-3/4" Cylinder outside bore (Into Head)

The above clues all seem to point to a 1964 engine, although the suffix code "YN" alone is inconclusive, as it was found on engines from 1961-1964. The 1964 heads could be bolted on to any 1961-64 engine, or even later engines if the 1964 cylinder barrels were used. The presence of a magnesium fan and a harmonic balancer crankshaft pulley, and a PCV system with a fixed orifice vacuum connection also points to the 1964 model year. The low profile air cleaners would be used on any Corvair van or truck. The original engines on vans, trucks and station wagons were fitted with a special oil filler tube that could be accessed from the rear access panel. It was attached to the bottom of the engine cases via a special casting.

Looks to be VERY cold in the Winter, but I suppose you get used to it.

My mother grew up in the town of Frankfort, MI, about 300 miles south of you — also on the water. You were right, in that the nearest CORSA club chapter appears to be about 200 miles south of you, in Kaukauna, WI.

North East Wisconsin Corvair,

http://newcc.weebly.com/

Corvair Forum