2.4 S or 2.7RS

[Astara]

I like to rebuild a 2.2T, but I can't decide where to.
I doubt between the 2.4S spec with 2.2S high drome pistons or a 2.7RS spec. engine.
Both delivers about 200-210HP, but what engine gives more fun?

Any who can give me any advise or have experience in one or both engines?

Ralph

[Steve@Rennsport]

JMHO,.......

For street engines, torque is King so a 2.7RS engine is the way to go.

[Henry Schmidt]

My favorite engine to build on the 3R case (2.2T) is the 2.45 Mod S (Twin plug if the budget allows.) Basically a detuned long stroke 2.5 ST engine.
86 mm is about as large as the 3R case can hold without boring the spigot and weakening the case. Plus the 86 mm Biral barrels are very affordable.
The engine is a 2.45 liter with DC Mod “S” cam and 9.5:1 compression.
Balanced the entire engine to 1gram.
CaseSavers, oil by-pass mod, 3.2 Carrera pump, line bore and oil squirters.
The 2.4 (70.4 mm) crank is magged, polished and cross drilled.
The pistons are JE 9.5:1 forged racing pistons in new 86mm Biral barrels.
The rods rebuilt new bolts & 12 point flanged nut.
The heads are 2.2 T with 36mm intake ports and machined for twin plugs.
Phosphorus /bronze valve guides and new valves (47, 41) installed.
The Supertec 240 valve springs. The head studs are of course Supertec.
40 mm Webers, SSI exhaust and M&K muffler.
This engine will produce 180 RWHP at 6400 with more to go if needed.



BTW: More torque then any RS spec carbureted engine.

[Astara]

@Henry Schmidt:
Looks very like the engine in this car you build:
Supertec 69 street rod R Group Contender

You used in this engine the AA cilinders, probably with Cryogenic treatment.
How is your experience now with these AA cilinders, and is the Cryo necessary?

Sounds like a great running engine; a lot of difference with the engine I described (2.4S spec w/ 2.2S pistons)?

[Henry Schmidt]

Originally Posted by Astara

@Henry Schmidt:
Looks very like the engine in this car you build:
Supertec 69 street rod R Group Contender

You used in this engine the AA cilinders, probably with Cryogenic treatment.
How is your experience now with these AA cilinders, and is the Cryo necessary?

Sounds like a great running engine; a lot of difference with the engine I described (2.4S spec w/ 2.2S pistons)?

It looks the same because it is.
When I build engines for my own projects, I try to be both performance oriented and cost effective.
As I get older, I see the advantages of clean, drivable power (as opposed to radical screamer) and the need to hold costs commensurate to the project.

We are finding more and more places where Cryo is proving to be effective. We are seeing the greatest benefit in components that are cast.
Things like cranks, cylinders, cams, rockers and most transmission parts. We also see great benefits in brake components. I'm thinking seriously about trying a mag case.
We have tried some forged and billet components with no discernible difference.

NASCAR teams are so convinced that many are doing the process in house.