PUCH vs Derbi Head for Hobbit

Dayton Bourassa /

Browsed the search function a bit, and can't seem to find what I am looking for. Has anyone had experience with both the PuchHobbit and DerbiHobbit head? It appears the Derbi one looks to have better cooling fins and should run cooler. Would be interested for anyones first hand experience feedback.

Currently would want a sport touring head for my PA-50II to have reliable cruising temps.

Re: PUCH vs Derbi Head for Hobbit

I grabbed the derbi head. So far my head temps have been in the low 300s. I have not tried the puch head to know how it compares.

The derbi one had an issue clearing the petcock that was installed on my tank. I think it is not an OG petcock and hangs lower. Just had to trim out part of a fun to make it fit.

Also the Dr kit with the derbi head required some cylinder studs over the dumb stock bolts. I grabbed the malossi puch studs that were like 102mm. They are a touch shorter than they need to be so anything between 102mm and 115mm will be perfecto. Anything longer and I would be afraid that the threading would end before you could tighten it all up.

Re: PUCH vs Derbi Head for Hobbit

Dayton Bourassa /

Hmmmm good to know. The mount for the engine is extended three inches back, so the tank and petcock on mine should not interfere any. I also have the head stud mod, but with threaded rod so there shouldn't be any issue with threads ending.

Thank you for the input. I think I may see what I can do with that one, and I may put much Puch one for sale. Its the "super street" which is more overkill than I wanted. If you or know of anyone that may want it, I will remove it and clean it up/inspect it.

Re: PUCH vs Derbi Head for Hobbit

Beach Club Nick /

I've had a Puch Airsal head that I slotted the stud holes on running on my hobbit for years. My temps went from ~450 to ~350

Re: PUCH vs Derbi Head for Hobbit

Dayton Bourassa /

My head would be mounted on a DR 70cc, but what exactly did you do? You put that head on and dropped about 100°?

Or slotted something and got the temp change?

Re: PUCH vs Derbi Head for Hobbit

Totally normal JBOT /

I run the biggest eurokit style head and it’s awesome. Most big heads will do what you want but you also have to do the important things to stay cool. Jet fat enough, don’t lug the engine with rollers that are too heavy, set timing so 18deg or less while cruising. Run the dr with thinnest base gasket or none at all with just sealant to get squish pretty much perfect

Re: PUCH vs Derbi Head for Hobbit

Beach Club Nick /

> Dayton Bourassa wrote:

> -------------------------------------------------------

> My head would be mounted on a DR 70cc, but what exactly did you do? You

> put that head on and dropped about 100°?

>

> Or slotted something and got the temp change?

https://www.treatland.tv/ProductDetails.asp?ProductCode=puch-airsal-46-head-04031446

What I'm saying is that the stud holes don't line up with the stud pattern on the Hobbit. You need to slot them so you can bolt this on. After putting one of these on my Hobbit my max temps dropped like 100°, no joke.

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