March 1, 2022

Early Denso "clamshell" heaters

Did you know that today is "Vintage Denso Heater Day"?! Ok, that may be a complete lie, but lets play along anyways. Hahaha. I wanted to share a special find for my 1965 FJ40 Land Cruiser and the cool history with it.

Early 1960s NipponDenso BA car heater

Its a 1963-1965 NipponDenso aftermarket automobile heater! This is what is known as a "clamshell" heater here in the US, or a "daruma" heater if you are in Japan. Why call it a daruma heater? Well in Japan there is a daruma doll, which is a round little doll that represents Bodhidarma, the founder of the Zen tradition of Buddhism:

Daruma Doll

I guess they thought of that when looking at the round little heater.

Now, if any of you remember our blog post on the history of the Denso corporation (HERE), we mentioned that in the 50s Denso and Bosch entered into an agreement that allowed Denso access to Bosch technology and to construct equipment based on Bosch products.

Early Denso & Bosch parts brochure

Well this cool little heater is the result of that agreement. Just look at the Bosch heater provided by @cruiserduber:

1960s Bosch clamshell car heater
1960s Bosch clamshell car heater
1950s Denso heater brochure

Back in the 1950s and early 1960s a heater in your Land Cruiser was not standard and was either an option at the time of purchase (OEM or aftermarket), or it was fitted later. This was true in Japan and the US and many 20 series and early 40 series (pre-1965) Land Cruisers didn't come from the factory with a heater as standard. How crazy is that to think about, a heater as an option! So if you went to buy a Land Cruiser from the dealer and opted for the optional heater....the OEM heater from the dealer would have been one of these super cool Denso Clamshell heater units!

Early FJ40 Denso heater. Photo credit landcruisnman (ih8mud).

Other more common outcomes for people wanting heaters here in the US would be to add a domestic aftermarket heater to your Land Cruiser. These mainly came in the form of the boxy shaped Hupp heaters. Cool little units as well when restored. Good info on other aftermarket heater HERE. All this crazy optional heater fun came to an end in 1965. Starting in about 1965, these aftermarket heaters stopped appearing as the FJ40 now came standard with the new OEM heater/fresh air intake system we know and love:

1966 FJ40 Land Cruiser heater


As great as the post-1965 heaters are, I REALLY love the style of these early clamshell units. Their style calls back to a different time and it's clearly made to be visually and functionally appealing, something you don't get now because a car heater is made to be hidden in the dash. The solid metal doors with the logos stamped in, the curved shapes, the exposed "burn your legs" heater core are all just fantastic.

I am really looking forward to installing this in my 1965 FJ40... that didn't come from the factory with a heater.

Notes for buyers:

I learned a couple things about this heater and some things to look out for when buying one of these old and rare heaters. First is that they came in 3 power flavors: 6V, 12V and 24V. So pay attention when buying. I bought this one thinking it was 12v but its 24V. How did I know for sure? Because thankfully we have uploaded vintage brochures for these heaters! I was able to BARELY make out the faded part number which confirmed my suspicions. Its not a deal breaker, I can run a small 12v to 24v converter and call it good. Its just a buyer beware thing.

Keen eyed observers may notice that these heaters also came with two different style front louver doors. The one I bought is stamped with NipponDenso. While the ones here in the US are more commonly found with just DENSO cast in the door. It is likely a market thing. NipponDenso mainly being used in Japan for a certain period of time, while the US got the Denso version. NipponDenso didn't officially change to Denso until 1966 and these heaters are definitely before then.

Another thing to watch for is heater core condition, it will be no surprise you cannot buy a new heater core for these things. They can be repaired or a new one can potentially be custom made if you find a radiator shop with skills. I have seen some NOS (new old stock) ones available in Japan, but they are likely unobtainable at this point. Additionally, make sure your heater has the rear defrost guide present and intact. They can go missing or get cracked and finding an original one will be almost impossible.

New old stock Denso heater cores

I do wonder though if a FJ40 rear heater core would work with minor tweaking? ;)

FJ40 Land Cruiser rear heater core

Now what is a post without more vintage literature? These brochures proved so helpful to me and I hope they help others that may need to reference the material as well. They are posted in the brochures section of the website: . Just scroll down to the bottom of the page to the "Accessories" section.

1960s Denso heater pamphlet
The wrap up:

As one last fun fact, notice the Deming Prize logo in the upper corner of some of the brochures. Some of you may remember that during an interview with Onur Azeri he mentioned that Toyota received the Deming Prize in the 60s for its quality control/parts system. Clearly Denso was proud of that achievement.

Well that about wraps it up for daruma heaters! I hope you enjoyed this little early cruiser heater history lesson. And for those on the hunt, good luck! Prices for these heaters can run up to $1000 or more, but deals can always be found with patience. ;) Cheers all and happy cruising! Thanks to @Indygbd and @cruiserduber on ih8mud and @dic.125 on IG for photos and information!

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