2.4 T, E, S? Options

[Cool914]

I picked up a 2.4T core motor I am going to rebuild to go in one of my 914's, someday...
It will just befor around town, maybe autox.

Question is regarding pistons, it needs new ones and I am either going to find some in spec used ones or go with JEs, and keeping the T cams or regrind E. I would like to get a little more kick out of it while I am at it but I will not be running an external oil cooler so wondering if I go with E (8:1) or S (8.5:1) pistons, would the increase in compression ior E cams mpact operating temperature to the point where I would need a cooler. Any experience, insight?

[PeeGreen 914]

I ran a 2.4E on my 6 without an external cooler and had no heat issues at all. It was a great engine.

[TorqueJunkie]

I picked up a 2.4T core motor I am going to rebuild to go in one of my 914's, someday...
It will just befor around town, maybe autox.

Question is regarding pistons, it needs new ones and I am either going to find some in spec used ones or go with JEs, and keeping the T cams or regrind E. I would like to get a little more kick out of it while I am at it but I will not be running an external oil cooler so wondering if I go with E (8:1) or S (8.5:1) pistons, would the increase in compression ior E cams mpact operating temperature to the point where I would need a cooler. Any experience, insight?

http://www.914world.com/bbs2/index.php?sho...=126644&hl=

here is the thread about my engine build. This is a great combination. If you have any questions feel free to contact me via IM.

[Cap'n Krusty]

I ran a 2.4S with Solex (similar to "E") cams in my bus for 10 years. Didn't even have to change the jetting, and I only had a heating problem once, mostly because I was towing another bus on a dolly and ascending a steep 10 mile grade. Kendall GT1 saved my butt .......................

The Cap'n

[TravisNeff]

I was reading about a supertech engine build that is somewhat cost effective, you don't need to do twin plugs with the compression ratio that was used


http://forums.pelicanparts.com/911-engine-...-4-s-2-7rs.html

http://forums.pelicanparts.com/911-engine-...eded-build.html

[GeorgeRud]

A friend just rebuilt his 2.4T engine using 911S pistons/cylinders, along with the MFI and original T cams. It's a very strong engine in his 911, and runs just fine without an external cooler.

[jmill]

You can go with 2.2 pistons (same diameter as 2.4) and you'll get an additional bump up in compression and HP. I have the same engine. I don't have the cash for the E or S p&c's so it'll be a T for a bit.

[Cool914]

Thanks for the quick feedback and links everyone, much appreciate and just what I wanted to hear. Sounds like it should be fun and safe....heat wise....

I thought about the 2.2T pistons but I would like to stick to regular octane (I am cheap)and the 9.1:1 is pushing that. Looks like custom 2.4S JE pistons and birrals are $1440, not bad all things considered, thankfully I got my core cheap.

Now back to the not so fun rust repairs.....

[flyer86d]

We have a 73 911T MFI car that we have owned for years and has been run in many PCA DEs, autocrosses, and time trials. When I rebuilt the engine, I upgraded it to E spec, sort of. I used 2.4 S P&Cs (because I got them on sale), E cams, E MFI (pump and stacks), and distributor. The port size is the same on the T and E motors.

The upgrade gained us about 30 HP which feels more like 80. Back in the 80s, my friends that were running 73 Carrera RSs would only pull about 2 car lengths on us up the back straight at Watkins Glen. It is a wonderfully torquey engine which pulls hard to 7300 rpm just like an S as long as you run a twin pipe muffler. Go for it!!!

[jmill]

Looks like custom 2.4S JE pistons and birrals are $1440, not bad all things considered, thankfully I got my core cheap.

Where do you see these? I have birals now and believed it wasn't a good idea to run the E or S pistons with them. If that's not the case I'll hone my cylinders and run the E pistons.

[JmuRiz]

I was reading about a supertech engine build that is somewhat cost effective, you don't need to do twin plugs with the compression ratio that was used


http://forums.pelicanparts.com/911-engine-...-4-s-2-7rs.html

http://forums.pelicanparts.com/911-engine-...eded-build.html

Now you're talking, the Supertec 2.45 is pretty friggin' cool. And like Henry says, you don't really need the twin plugs unless you are well over 10:1 compression ratio.

[Cool914]

Looks like custom 2.4S JE pistons and birrals are $1440, not bad all things considered, thankfully I got my core cheap.

Where do you see these? I have birals now and believed it wasn't a good idea to run the E or S pistons with them. If that's not the case I'll hone my cylinders and run the E pistons.

I have not heard that. Original 2.4E and S used birrals instead of cast iron 2.4T as I understand it.
You can find JE sets them lots of place, most porsche sales sites , but you can call JE and have them make custom to whatever compression you want. http://www.ebay.com/itm/Porsche-911-84mm-J...459&vxp=mtr

[Cool914]

I was reading about a supertech engine build that is somewhat cost effective, you don't need to do twin plugs with the compression ratio that was used


http://forums.pelicanparts.com/911-engine-...-4-s-2-7rs.html

http://forums.pelicanparts.com/911-engine-...eded-build.html

Yes, that is tempting...

[J P Stein]

I lkie the JE idea.
Using 2.2L pistons in a 2.4L is iffy unless you can do some good measurements.
The 2.4L pison is different.....the pin hole is relocated in comparison to the 2.2L to help with the longer stroke of the 2.4L crank. Deck height can be fixed easily but possible intererence exists at the bottom of the stroke.....checking for this is a stone bitch.You need a minimum of 1mm+ (.06 would be better) clearance from everything down that dark hole.

2.4L E motors were Brial but that was 35 years ago. Nikasil came on the 2.4L market 20 odd years back. They are un-cheep. If you have Brial they can be bored 1mm over and JE pistons can be had for this and 9.5:1 compression to boot.

If you can get a set of STD Brial PCs (& the JEs) for 1200 bucks that's a slam dunk.
Iron sux.

[ClayPerrine]

I have a 2.4 ST motor in my car (ST = S pistons, cylinders, and cams, T heads) with the MFI. I used 2.2 E Mag Stacks. It runs really strong. But the new ethanol laced gas ate the MFI pump seals.

I want to go to 2.2S pistons and 904 cams with twin plug. That plus the EFI setup I am building now should be great.

Do the 2.4 S pistons and cylinders. They will work fine.

[BK911]

We have a 73 911T MFI car that we have owned for years and has been run in many PCA DEs, autocrosses, and time trials. When I rebuilt the engine, I upgraded it to E spec, sort of. I used 2.4 S P&Cs (because I got them on sale), E cams, E MFI (pump and stacks), and distributor. The port size is the same on the T and E motors.

The upgrade gained us about 30 HP which feels more like 80. Back in the 80s, my friends that were running 73 Carrera RSs would only pull about 2 car lengths on us up the back straight at Watkins Glen. It is a wonderfully torquey engine which pulls hard to 7300 rpm just like an S as long as you run a twin pipe muffler. Go for it!!!

I had this exact engine is several early 911s and was BY FAR my favorite.
I am building another one very similar because I miss it so much. (IMG:style_emoticons/default/sad.gif)