Service needs for DOHC 240 SX?

[Dougster]

Hey guys, I owned 2 of the early 240's a 89 & a 90 with the SOHC engine and thought it was a reliable durable engine. I am now considering a move into the DOHC 2.4 240's...Do they require more service or the same? How long before you should replace the timing chain & water pump?I liked the SOHC powerplant, but thought it was somewhat underpowered. Are the 15 more HP of the DOHC noticable? Is it easier to mod & get results? What kind of gas mileage does the DOHC engine get? About the same? Any other differences or advice is great, thanks much & happy motoring!

[Repo Man]

Hey guys, I owned 2 of the early 240's a 89 & a 90 with the SOHC engine and thought it was a reliable durable engine. I am now considering a move into the DOHC 2.4 240's...Do they require more service or the same? How long before you should replace the timing chain & water pump?I liked the SOHC powerplant, but thought it was somewhat underpowered. Are the 15 more HP of the DOHC noticable? Is it easier to mod & get results? What kind of gas mileage does the DOHC engine get? About the same? Any other differences or advice is great, thanks much & happy motoring!

Having driven both the SOHC and DOHC, I think there is a definite difference. One reason the DOHC may make more power, aside from the obvious differences, is the fact that they're newer. Maintenance is also an issue. A well-maintained SOHC will probably make more power than a neglected DOHC.

The DOHC (KA24DE) is a pretty low-maintenance engine, especially compared to a DSM engine, rotary or whatever. The timing chain is usually an issue at around 100k, but if that's taken care of then it's good to go. Water pump is in the same boat. Good preventative maintenance for another 100k.

As far as mods go, I think there are more available for the DOHC. I feel there is more potential there, but the SOHC can certainly be built up as well. A header really increases power in the upper rpm range as the stock exhaust manifold is pretty restrictive. I've run a 15.8 with mine in pretty warm weather with a large toolbox, subs and amp in my trunk on worn out tires. My only power mods are intake and exhaust (with a test pipe). I think my car has the potential for a 15.5, maybe a little better if I do my part.

I can get 30mpg on the highway and 25mpg city. Another good thing about the 240 is that it is low insurance because it is not classified as a high-performance car, even though the chassis has incredible potential and is an excellent handler in stock form.

[Dougster]

Good points! Thanks for the imput. Any idea what HP your pushing now? Could you notice any dif when you did your mods?

[Repo Man]

I haven't done a leakdown test on my car yet, but I would estimate 160-165hp at the crank given the mileage and mods. It runs strong, without any misses or hesitation all the way to redline. There is a definite difference that can be felt and heard when an intake an exhaust are added to an otherwise stock 240.

I'd like to get it on a chassis dyno, but have not had the opportunity.

[Dougster]

Yes, it does look like you have a nice one Andy, I will be interested in seeing it sometime. How do you like your Borla Exhaust? Nice throaty sound?I have read where some na engines lose some torque on the low end with test pipes & low or no restriction exhaust, but make it up on the high RPM's, how does yours feel in that regard?