Engine and Transmission Tech

Considering a 215 Olds swap in our families 1966 Volvo Amazon estate.
1st question)
Anybody run a mostly stock 215 and if so, is it possible to get decent gas mileage? I'm thinking mid to high 20's and I will give it a go. Thinking a T5 transmission and likely losing the 4.56 gears.
Opinion, ideas welcome!

2nd question)
Would a stock 185HP 215 get me there? (re: MPG)

3rd question)
Single or dual exhaust? Re: sound. Is there a "exhaust video" thread here? (I know, I know not accurate, but its a place to start)



Edited 1 time(s). Last edit at 12/26/2014 04:25PM by nonhog.

IMHO... a five speed and a better rear axle ratio will both help a lot. You didn't mention camshaft selection, but your cam will have a big effect on both tone and MPG. Exhaust probably won't effect mpg much. 215s tend to sound "bigger" than they are. Aluminum sounds different than iron. Valley pans let out a lot of noise. The later-model Rover pans are rubber coated, and that helps. (I recommend them.) 20-24 around town and 24-28 on road trips is probably reasonable to expect, assuming your driving style isn't too rambunctious and that we're talking U.S. gallons.

"You didn't mention camshaft selection"

Still learning and researching, figured posting here could start me in the right direction.
Thanks for the response!

You also need a high compression ratio to get the good mileage. I'd go about 10-1/2.

Jim

I've got a nearly stock 215 in my 62 F-85 wagon. With the crappy RH5 automatic and 3.36 rear (and a heavy right foot), I get high teens. The single/dual exhaust question is irrelevant. What matters is total flow. The 61-63 Y-body cars are configured for a single pipe in the tunnel, so I ran a single 2.5" pipe to a Magnaflow Camaro muffler (one in, two out). If a pair of 2.5" pipes are adequate for my 455 Olds motors, a single one for 215 cu in is more than adequate. To be honest, a single pipe will flow better than two pipes of equivalent cross sectional area, since the two smaller pipes have more surface area in the pipe wall and thus more boundary layer drag inside the pipes.

Re: exhaust my reason for asking single or dual is purely for that Hot Rod sound. Not to be confused with louder is better.
I'm not in the larger is better camp. There are a few really nice sounding 215 MG video's on YouTube but none mention the exhaust set up.
I just built a single system for the V8 Volvo I am building for my wife. It has a 3" Dynomax bullet muffler that will also have a Super Turbo. Hoping for a throaty burble. Crossing my fingers. So it doesn't have to be dual. Again curious about the sound.
I get its subjective.

Bullet and Super Turbo in series... I'm curious about that sound too.

My guess is that the turbo will have significantly more attenuation effect in general and also provide it over a wider frequency range, trumping the glasspack (Bullet). I like the turbo sound... I think of it as the sound of my youth whereas I guess that the glasspack sound is more popular with older guys. I've been using dual Thrush turbos with my 215 from the beginning. I picked them because they were small, lightweight, and cheap! I've been thinking for a long time that when I get around to re-doing my exhaust system I'll upgrade to dual DynoMax turbos. Thrush and Dynomax are just two brands within the same company, and I can stick with the compact size. The Dynomax version has some fiberglass filling and an extra segment of pipe inside the muffler compared to the (cheap and cheerful) Thrush version - so it should be a little quieter overall and also a little more rumble-y. Maybe.

For sure, where you dump the exhaust will have a lot of effect on how you perceive it. I used to have my pipes pointed out the side, and now I've got them pointed at the ground, but in both cases they terminated forward of the rear wheels. From the curb, my car is quieter now (and maybe a little more bass-y.) Inside the car, it's louder. As I drive past through downtown, I no longer perceive the volume going up and down (due to reflections off the buildings). Extending the pipes and pointing them out the back would make my car quieter - especially as perceived from my driver's seat. With exhaust pointing at the ground, I kick up a lot of dust on gravel roads, including my own gravel driveway.

I always had the Turbo mufflers ahead with the glass packs in back as resonators. A little deeper tone and not as raspy.

You didn't mention tire dia.-BUT, I think some T5's have a .67 od. ? This would take your 4.56's down to 3.0, should help your mileage goals, as would a modern carb. Good Luck, roverman.

Modern carb? I've noticed a few Holley 390cfm, but have yet to study up on that. Love to hear suggestions.

Oh and sorry if I missed it? Subscribe to threads?

I'm thinking mid to high 20's and I will give it a go. Thinking a T5 transmission and likely losing the 4.56 gears.


i'm assuming highway mileage ...

how fast do you intend to cruise? you want to design your drivetrain ( including tire dia ) to keep your rpm at cruise, in top gear, LOW. 2000rpm, maybe a bit less. specifics will depend on the drag of the car, low end torque, curb weight, etc.

an rv / towing cam would suit your purposes far more than a HP / rpm cam.

i have no idea what your tire size is, but if i plug in a .63 OD T5 with 205 / 70 - 14 ( ~79.5" circumference ) with a 4.56 rear i'm getting ~2700rpm @ 70 mph. shorter tires ( 13" rims for example ) will take operating rpm up for a given speed.

that's much too high for fuel mileage.

a 3.23 rear with the above specs gives ~1900 rpm, which should be about what you're shooting for.

Here is a vid of my TR8. Magnaflow mufflers in the middle with H pipe. Read is Rimmer stainless stock replacement. This is last year with the anemic fuel injection, running lean. This year will sound much healthier.

[youtu.be]