2,4 upgrade
 

My name is Henrik and I'm from Sweden.

This is my first post. Very interesting and useful information in the forum but i have not found (not looked enough) any information about the 2,4S pistons...

I rebuild/upgrade a 2,4 engine with ported heads, E cams and 2,4S pistons and 40mm Webercarbs.

I'm planning to fly cut the heads to get a little bit higher compression. I'm not sure but is the compression with 2,4S pistons 8.5:1? in a 2,4 engine?I would like to get it raised a bit higher. In Sweden we have great fuel 98 Octane gasoline.

How much can I flycut the heads without get worried about the chaintensioner? I understand that i have to cut the chainhouses as well?

What do you guys think about this engine combination ?
How much power do you think it will produce and at wich rpm?
Peak HP?
Peak tourge NM?

The engine is not been installed in a Porsche 911. it is transfered in to a 1966 VW deluxe/samba bus. I have a 901/5 speed gearbox from 1967 911 and i guess i need tourge better then top power.. The bus is about 1400kg.

Engine:

Webercarbs
2,4S pistons
Early E camshafts regrind.
Heads ported 37mm intake and 35mm exhaust.
Manifolds ported to match up with heads and carbs.
Stock headers with a custom SS exhaust dual in/out
Compression 9-9,5:1 but stock have to do if it is a lot of problems. to raise the compression.

Thanks
//Henrik...SWEDEN up North

An option to raise compression without flycutting the heads is to use 2.2L pistons. That's what I did. This way, you don't have to worry about added machining tolerances, and how they might affect the rest of your engine.

Good luck, and welcome to the forum. There's alot of good info here.

About the same as a 2.4E
Most likely a touch better then a 2.4E

Switching from MFI to carbs will most likely cost you about 10 HP from a stock E, but then the higher CR should make some of that up. The higher CR will most likely boost the torque a little bit across the rev range which will make the engine easier to drive.

I'm sure that you'll love it!

If this were my engine, I would go with something like a mod-S cam, which is a bit hotter than the E cam...

-Wayne

OK... The engine is not been installed in a Porsche 911. it is transfered in to a 1966 VW deluxe/samba bus. I have a 901/5 speed gearbox from 1967 911 and i guess i need tourge better then top power.. The bus is about 1400kg. Will this engine work better with S cams then E cams in my bus?

//Henrik

If you cut the heads, you need to cut the chain housings to. The same material that you remove from the heads you will need to remove from the chain housing from the side that face to the engine.

Yes I know but how much is maximum fly cutting that could be done before i need to change the sprockets etc? wath is the minimum depth of the head from pistonside to camhousing? I will take the heads to the machine shop and need to know how much materiel he can take away.. Valve clerance is a later problem if any at all.

//Henrik

SWEDEN

Jay is right - you should run the 2.2S pistons instead. Cutting the heads leads to other problems with the chain lengths...

-Wayne

I would opt for a 3.2 over the 2.4 in the bus. The cost might be about the same as rebuilding the 2.4. I had a 2.4E w/carbs & '73 trans in my '68 vw crewcab. I recently switched to a stock 3.2, '84 915 w/7:31 r&p. As you mentioned, the power wasn't as important as the torque. http://forums.pelicanparts.com/uploa...1103729163.jpg