TheSamba.com :: View topic - 1835 Single Port Dieseling, super hot apron?

Mon Jul 08, 2019 6:26 pm

We just built an 1835 single port for our 60 single cab and got it put in. It runs great and has tons of low end, but has a couple issues that I can't figure out.

It has a 30-Pic3 Carburetor on it, and the timing and everything seems to be correct. It runs great driving down the road, but searches a little at idle. When it's warmed up and you shut it off, it diesels for a couple revolutions after you shut the key off. It has a working cutoff solenoid - are there different lengths or something that would cause that? It really only does it when warmed up.

The motor has a 1 3/8" header with heater boxes and a quiet pack, and when it's up to operating temp the apron and bumper are HOT. You can put your hand on the decklid, but you can't keep it on the bumper or apron. The motor seems to be running plenty cool, so I have no idea what would cause this?

I don't know if the two problems are related at all - any help or ideas are appreciated.

Mon Jul 08, 2019 8:35 pm

its obviously running hotter than you think it is. the apron should not be too hot too touch, even with a header. the quiet pack is hanging below and behind the bumper, so its heat should not contribute to the apron.

how do you know your timing is correct? Have you jetted the carburetor for the larger engine? does it have a performance camshaft? correct deck height and compression for given cam? 100% correct tin in place and sealed?

sounds too lean or timing off to me

Mon Jul 08, 2019 8:47 pm

My brother has a single port that is the same, only 1600 though. Super hot exhaust and timed correctly. Maybe a little rich and burning in exhaust. Haven't checked jetting yet. Using a 30/3 too.

Mon Jul 08, 2019 10:00 pm

What timing is correct to you? Aim for 30 degrees at full advance to start with.

Tue Jul 09, 2019 4:27 am

Once the key is turned off the timing is out of the picture as the ignition system is shut off.

Is the engine cool enough to hold on to the dipstick?

Spark plugs the right heat range, the right length or is there threads exposed in the chamber?

The carbureted engines in the later years had a tendency to do that on hot days so VW put the idle shut off valve on the carb. The leaner running carbs for emissions was part of the reason. I would question that it is working properly.

Tue Jul 09, 2019 6:12 am

An 1835cc engine will produce double the hp and more heat than the 1960 Type 2 was designed for. So consider more air flow and oil cooling too.