What stops someone using 356 heads on a Type 1?

[MVB]

I heard it can’t be done. Is it just one has to ignore the extra head bolt hole on each end of each head & the completely different rocker layout would require a different or custom cam? Or are the heads dimensionally so different that they won’t line up, even with custom machining?

BTW I often wondered why no one has done a forked rocker setup for multivalve heads running off pushrods for the ACVW, similar to the way it’s done in the Honda CX, Moto Guzzi Daytona, the Triumph TSI & Horner Racing 8 Valve Vincents, but i s’pose getting a ACVW engine working with pushrods that aren’t parallel gets the idea into the ‘too hard’ basket. BTW those Horner Vincents are running at 13:1 compression while still being air cooled.

Thanks in advance to any replies, ta.

[Alstrup]

[MVB]

Surely the canted valving adds something, even if it’s just means potentially bigger valves.

I think the ARAO heads (with one rocker pressing against another rocker) to get 4 valves per chamber has the same issue that Cummins 24 valve heads have, which use a bridge across 2 valves being pushed down by 1 rocker. In that the system doesn’t support any cantering of the valves, as they have to be parallel to each other. Forked rockers allow the inlets & outlets to canter towards each other. Meaning greater potential in a number of ways

Gez is there a way of shrinking images during the posting process, or does one have to do that in a image editor before uploading, ie manually?

Anyway thanks for replying, Al.

[Dan Ruddock]

Arao is no more. I worked for Arao for three years back in the early 90's. When I found out Russ closed the doors, I was not able to get ahold of him for years. Finally, about six months ago a new customer of mine had a connection to him and I able to talk to Russ. He had a lot of problems with pushrod failures from one pushrod opening two valve springs. Better pushrods solved the problem as long as the cams ramp speed and spring tension were not too excessive.

IMO, just use an engine that is engineered from the ground up with the modern head design or optimize the design that is already there.

The bore spacing of the 356 head will only fit the 36hp VW engine. Waste of time.
_________________
Cars, 1961 bug, 2016 Mazda MX-5
Engine 2234cc
Porsche 912 rods
84mm DPR
42 X 37, 74cc port volume heads ported by yours truly.
44idf/48idf
Webcam dual pattern 252+3 .535" lift intake and 86a +6 .485" lift exhaust
1 5/8 long merged exhaust
CB 1.4 rockers on Berg shafts
Gears, 3.10, 1.94, 1.32, .89 and a 4.37 R&P

[MVB]

[Dan Ruddock]

[Dan Ruddock]

[MVB]

[quote="Dan Ruddock"]

[modok]

Slightly canted valves like in the gol would be nice.
But the slight improvement hardly justifies the added complexity.

The 356 heads were designed more for cooling than power, and very few are excited by that these days.

[nextgen]

Since 1993 I cannot count the amount of men and women that bought my manual, to install a T-4 in their 356. They wanted the T-4 because it was less expensive and could easy go over the HP of a 356. Also in some countries or states, the engine has to be original. Very hard to tell an up right converted 356 with a T-4. Plus what got me into the conversion was when I looked my long block T-4 engine and put it next to my T-1 long block the tranny bolted right up. Another reasion I was told was the original a running 356 engines is extremely expensive and stocking the original away would keep value of the 356.
You can still get T-4 parts and not as expensive as a 356...

I know this started with the 356 Heads. But I did not see the logic.
_________________
email: [email protected]
The TYPE IV UPRIGHT CONVERSION MANUAL
BEETLE MAGNETIC DEFLECTOR SHIELDS
LETS TALK DUBS https://www.youtube.com/results?search_query=joe+cali+ghia https://letstalkdubs.libsyn.com/ep-200-joe-cali-ty...qI3xJTCzjs

[jpaull]

[modok]

Oh...quit your whining. It's just as topical as half your posts.
Type 4 has far higher HP and cooling potential than a 356
It's more or less along the lines of what I was going to say but didn't. Porsche design evolution did go in the right direction, so what did they miss?

Four valve head would greatly reduce the cooling passage area, so it was not a viable option for an aircooled gasoline burning automobile capable of endurance.
That was known in a general sense at the time, from aircraft technology.

Some motorcycles can get away with it, but it "won't fly" in other vehicles which are more taxing to the engine

[nextgen]

Hi jpaull thanks for the kind words, I appreciate my groupies!!!

I know how found you are of my photos, so here is another of my first sales back in 1993 . in VW Trends Mag..
Notice no Internet at the time yet to this day still selling to people interested in T-4 conversions, world wide and I just placed an order for another 50, so if you are interested I will knock off $5.00 bucks, ha..

I have sold thousands of them in 30 years. In my last post my information about the 356 engine was from years of experiance of 356 owners interested converting their 356 over to a more power full and less expensive conversion and hold onto the real money of their original engine and have fun driving.

I have sold thousands of manauls and and hundreds of them were to 356 owers.

Modok thanks for your explanation, I hope it helped my Groupie to understand the 356 vs T-4 story I was trying to across.

_________________
email: [email protected]
The TYPE IV UPRIGHT CONVERSION MANUAL
BEETLE MAGNETIC DEFLECTOR SHIELDS
LETS TALK DUBS https://www.youtube.com/results?search_query=joe+cali+ghia https://letstalkdubs.libsyn.com/ep-200-joe-cali-ty...qI3xJTCzjs

[MVB]

[modok]

I wasn't able to find much tech detail about this racing Vincent but I did see it has a big fuel tank.
Does it run on methanol?

[panel]

[MVB]