impact of no heater on CHT?

[Davidsquared]

Hi, the 68 Ghia cabrio I bought has straight pipes to the muffler. The heater system has been removed. The alu heater hose in the engine comparement end at the floor and are not connected to anything.

This car will never intentionally see bad weather, its my fun summer car. I do intent to drive it however, I am not precious with things. I do not have a engine temp guage on it, I plan on adding one.

The engine operating perameters were designed with an intact heater and I assume to some degree removing it will have an impact on how the aircooled engine sheds heat. Has anyone determined how significant (or not) this is? Take CHT readings with and then with the heater gear removed in similar weather and driving conditions?

Before I start doing long highway runs I would like to understand how its managing over heathing.


THanks
David

[jeffrey8164]

Just get some block off plugs to go into the fan shroud outlets. That will stop the bleeding so to speak.

https://www2.cip1.com/acc-c10-5439/
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Turning owners into mechanics since 1938.

“Let he that is without oil throw the first rod”
(Compression 8.7:1)

[runamoc]

check out this forum discussion

https://www.thesamba.com/vw/forum/viewtopic.php?t=755518
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Daily driver: '69 Baja owned 44 yrs - Plan B: '81 Rabbit Diesel LS Deluxe - Plan C: '72 Ghia
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Outback: '69 Ghia - '68,'69,'70,'72 Beetle - '84 Scirocco, GTI - Pair of '02 Golfs-
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[Era Vulgaris]

Do not use fan shroud block off plugs. Jake Raby has proven with actual data, that fan shroud block off plugs create turbulence inside the fan shroud, which disrupts airflow and increases head temps.
It's just like with a river, if it has an offshoot that gets blocked, the eddies back up into the flow of the main river and disrupt the current.
Even if you had heater boxes installed, that air would leave the fan shroud anyway, pass through the heater boxes, and then get dumped out under the car (or into the cabin if heat is on). It's not "lost" air just because you don't have heater boxes.

https://www.thesamba.com/vw/forum/viewtopic.php?t=153387

You can leave the fresh air hoses as they are, or if you want to get rid of them get a fan shroud that doesn't have fresh air outlets. But don't fully block the outlets on a fan shroud that has them.

Running j-tube exhaust pipes won't increase your head temps. What will increase your head temps is having heater boxes installed with no fresh air running through them. What will increase your head temps is not having all of your cooling tin in place. Familiarize yourself with all the pieces, and make sure it's all there. What will increase your head temps is running low rpms under high load situations (ie highway speeds and/or uphill grades). What will increase your head temps is incorrect carb and timing adjustments.
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Currently own:
66 Karmann Ghia, L390 Gulf Blue, under construction, here: www.thesamba.com/vw/forum/viewtopic.php?t=760505&highlight=
99 Mazda MX-5 10AE, Sapphire Blue Mica, 6 speed, LSD

Previously owned:
98 Porsche Boxster, silver, 2.5L -- 67 Karmann Ghia, Black, 1500sp -- 98 BMW Z3, Atlanta Blue Metallic, 2.8L I6 -- 75 Porsche 914, Laguna Blue, 2270cc -- 72 Porsche 914, Signal Orange, 1.7 FI -- 74 Karmann Ghia, Black, 1600dp -- 74 Triumph TR6 with O.D., sapphire blue

[kingkarmann]

I have successfully ran my 67 coupe for 17 seasons using "J-Pipes" with no issues.
They make a rear tin without the holes for fresh air exchangers/outlets.
There are a couple of options for the shroud.

1. Shave the fan shroud outlets and weld sheet metal over the opening. I did this for mine.
2. Purchase a shroud from a 73 Thing. That year did not have fresh air tubes.

As an afterthought I suppose you could leave the fresh air system in place. I don't believe it would have any negative effects.

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"Depression is a malfunction of the instrument we use to determine reality.”

Mike Gerson

What is your "Bespoke Reality"?

[jeffrey8164]

Me too, but only 12 seasons.

_________________
Volkswagen!
Turning owners into mechanics since 1938.

“Let he that is without oil throw the first rod”
(Compression 8.7:1)

[jeffrey8164]