TheSamba.com :: View topic - Scored a '79 Heat Exchanger/Exhaust system + Tin

Mon Nov 09, 2009 11:40 pm

Local guy was parting out a '73 Transporter that had a near-complete '79 federal engine (sans EGR & EFI). He let me have the heat exchangers and 8 pieces of tin/tubes/brackets needed to convert my '75 system for $50 \:D/ Even got the seals for around the heat booster tubes where they exit the tin on driver and passenger sides. I realize that this system requires square port heads, which is the only bummer... I won't be able to use it until I need to rebuild. Are there any other differences between the '79 HXs and the '72-74 HXs? I vaguely remember reading somewhere about one having more internal fins. I do recall some statements about the square ports having better sealing gaskets than the ovals.

I do have the '79 federal exhaust w/ cat (egr ports welded shut) - assume this might be desirable for someone in an area that needs smog testing?

Will post some pics tomorrow. Stoked though... gotta love craigslist!

Tue Nov 10, 2009 6:29 am

Well the 79 buses have square ports at the heads, so I doubt that you can get them to fit on the round or oval heads you have.

The 789 CA model has the very funky left heater box that requires the cat converter and has provisons for the O2 sensor. The right side heater box is a 79 only thing but the same for a federal model. They are a one year only thing.

Tue Nov 10, 2009 6:58 am

I am interested in the exhaust. Can you send me some pics?

Tue Nov 10, 2009 9:25 am

Thanks for the input Randy. Yeah, I know the square ports won't fit my current 1.8 oval port heads... like I said, I will have to wait until a rebuild is needed and switch over to the square port 2.0 heads. When I responded to the craigslist ad, I was expecting the the engine to be the original '73 1.7, but when I showed up last night to check things out I realized it had been exchanged at some point with a '79 2.0.

Do the '79 heater boxes have the same improved exhaust flow & heating characteristics as the '72-74? That is my whole motivation for wanting to make the change. Plus I'm thinking about a Camper Special when rebuild time comes and know some exhaust improvements are necessary.

Quote: The 789 CA model has the very funky left heater box that requires the cat converter and has provisons for the O2 sensor.
What about the left heater box requires the cat? The trapezoid exhaust mounts are the same as 72-74 and all the exhaust systems I've seen list application for 72-74 & 79.

Tue Nov 10, 2009 10:27 am

I have seen square ports cut and trimmed to fit ovals, although the opposite conversion is much easier.

Tue Nov 10, 2009 10:59 am

patayres wrote:
What about the left heater box requires the cat? The trapezoid exhaust mounts are the same as 72-74 and all the exhaust systems I've seen list application for 72-74 & 79.

I think it's more accurate to say the left heater box on a '79CA is designed the way it is to accomodate the cat. It you wanted to run without the cat you would have to fabricate a straight pipe.

If you truly have a '79 California I don't think you can bolt up a standard exhaust. Are you sure it's a California and not a Federal?

California:

Federal:

Tue Nov 10, 2009 11:04 am

I have a complete 79CA heaterbox to heaterbox including the exhaust/cat/o2 sensor set up all in one piece. I will try to take a photo of it and get it posted.

Tue Nov 10, 2009 11:15 am

Sorry guys, after looking at the diagrams WhirledTraveller posted I realize that it is a '79federal system :oops: I've corrected the original post.

I'd be interested to learn more about the cutting/adapting mod that fusername mentioned, although if the square ports are superior in sealing vs. the ovals I think I'll just leave it and change heads when necessary (mmm Camper Special =P~ ).

I'd also appreciate anyone's input on whether the '79 fed heater boxes have the same flow & heating benefits as the '72-74.

Thanks guys!

Tue Nov 10, 2009 11:42 am

Usually the Raby Camper Special uses 72-74 heads and heater boxes. The heater boxes are really not the "flow issue" though, it has more to do with the heads.

Mine does and I bought new used heaterboxes to do it. I am running a Thunderbird header, but will be going to the tangierine designed one that Jake sells come spring.

I think you could use the square port heads if you wanted to for additonal cost, but I will defer to Jake's judgement on that one.

Tue Nov 10, 2009 1:53 pm

Jake sells the square port heads on his website for the same price as the oval port (I checked that as soon as I got home with the boxes and tin).

By improved flow I meant that I'd read they breath better, as mentioned in this post http://www.thesamba.com/vw/forum/viewtopic.php?t=2...mp;start=0

I got this stuff in anticipation of the Camper Special rebuild and just want to make sure that it's just as good as the '72-74 boxes.

Another question I have, which I have searched but can't seem to locate anything definitive, is how compatible the 2.0 square port heads are with my 1800 EFI. IIRC the 1800 has 93mm pistons vs. the 94mm in the 2.0... will my 1800 case accept a 94mm piston without needing bored out? Or, conversely, will the 2.0 head bolt onto an 1800 cylinder (I realize this changes compression ratio). What is typically done with a Camper Special in an 1800 EFI engine? Is it kept 1800 or upsized with larger P&Cs, heads, crank, etc?

Sorry for all the questions but I really appreciate everyone's advice!

Tue Nov 10, 2009 2:04 pm

I could not see any mention in that post about how the heater boxes have anything to do with the flow of exhaust gases.

Restriction of the flow of exhaust gas really has more to do with the crossover pipe and the stock muffler IMO. Those new heads from Jake and HAM will exhale nicely if they do not have to go through a restrictive exhaust system.

The 72-74 heater boxes I got from interstate VW were all of the nice german ones with lots of fins. I live in Maine where heat is sometimes a desirable thing, even in July.

Tue Nov 10, 2009 2:32 pm

It was your post Randy :D
Quote: Common to do and I did the same thing. They breath a little easier.

Anyway, I'm mainly trying to find out how well these '79 heater boxes figure into the eventual Camper Special.

Tue Nov 10, 2009 2:49 pm

Don't listen to that Randy guy. He is way over-rated. :P

I would call Jake and ask him what he suggests.

That is what I did and why I did the 72-74 thing.

Tue Nov 10, 2009 6:55 pm

The 72-74 and 79 fed heaterboxes flow way more heat to the front than the 75-78. I have driven both in snow (74 and 78). The only difference between the 79 fed and 72-74 is the square ports. I can't comment on modifying the ports on the HE's, but 72-74 HE's are way easier and cheaper to get than rebuilt heads. Better to buy an early set of HE's out of the classifieds. You can use all the 79 tin and other stuff with the earlier HE's, in fact it is better than 74 tin since you aren't running carbs.

2.0 heads bolt up to 1.8 jugs no problem, or so I've been told. :?

Tue Nov 10, 2009 7:01 pm

2.0 heads and 1800 jugs play together fine.

the heaterboxes flow better because of two pipes coming off the heads and mergeing further from the heads, allowing some real scavanging, esp if you run a merged collector at the end, rather than stock mufflerparts. the 75-78? style with the little F pipes is terrible due to lack of scavanging and it flows less, however I think the scavanging issue is a bigger deal.

square ports are easier to seal to the head than ovals, metal or paper gaskets on teh square (easy to align and seal) vs the copper rings (oh god kill me now) on the oval ports.

Tue Nov 10, 2009 7:57 pm

Cool. Good to know.

I've got a call into Jake Raby, but have also just read a post of his on the RAT forum that the CS kits may be permanently discontinued :( His dad just passed away and things are on hold.

Jake if you see this thread - sorry for your loss. As you decide how to proceed in 2010 I hope you'll consider keeping the Camper Special kit available [-o<

Tue Nov 10, 2009 11:40 pm

I have 79 square port heads from Jake; they're the same price either way and you get the benefit of an easier sealing head. I also have the 9550 cam and essentially everything else to make my engine a special camper if not a camper special.

If you've already got the square port heat exchangers, rock on. I have tried the 79 CA only exhaust (in my now defunct attempt to make my bus smog capable) and found that it's just horrible. But the 79 Fed heat exchangers with a decent collector bolted to them really ups the power. The crossover pipe is a killer of power also, but if you've got a good one, it's worth some cash b/c they're a bitch to find. In fact, if you interested in selling it, I'd be interested in buying it.

Good luck with your camper special. If he quits selling the kit, he will likely still sell all the parts which are necessary to get from him, such as the heads, valvetrain upgrade, and oil pump conversion, since they're common to other setups as well, and you can just go the cheaper special camper route and source your own crank, pistons, cylinders, and whatnot.

Let me know if you'd be interested in selling that crossover pipe. :D

Wed Nov 11, 2009 7:59 am

I'd also point out, that Scott of German Supply has been putting together high-performance type 4 engines and is selling the parts to do so, such as upgraded large-valve AMC heads and web-cam of his own design. Scott knows what he is doing, is price competitive, and contributes a LOT to the community. Raby is not he only source out there...

Wed Nov 11, 2009 9:47 am

That's a good point. I didn't mean to make it sound as if Raby is the only source for good t4 stuff.