How much power is lost through a 518

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Splittin hairs. Put the 518 in it and gear accordingly.
 
You will need to clarify what you are talking about here .
Here ya go
To find your cruise timing at that rpm; (edit; minimum cruising rpm), just keep tugging on the timing, while simultaneously reducing the rpm back down to the minimum cruising rpm, until the engine no longer builds rpm. Edit; I use the fast idle cam to set the minimum cruising rpm.So for example; you add 3 degrees timing and the rpm goes up say 200rpm. You back it down the 200 and add 3 more degrees. This time it might only rise 100rpm. So you back it down, and add 3 more and this time it goes up only barely, so you take the last 3 degrees out and call it done. End Edit.
 
Splittin hairs. Put the 518 in it and gear accordingly.

Small blocks 340/360 get about the same mileage it doesn't matter what you do.
If you veer from stock cam into performance cams... the mileage just goes down at a certain point.
15-17mpg.
318, little better .now Slant 6... 40 mpg ,mother f'r, just ask any slant owner. Lol jk
 
Small blocks 340/360 get about the same mileage it doesn't matter what you do.
If you veer from stock cam into performance cams... the mileage just goes down at a certain point.
15-17mpg.
318, little better .now Slant 6... 40 mpg ,mother f'r, just ask any slant owner. Lol jk

But you're right. Slant guys who got 35 plus MPG are around every corner. Just wait. One will be along any minute.
 
I have never ever been able to get a slanty up to the numbers of a hi-compression 360, even after I took it apart, and boosted the compression up to a true 9.5. And spent way too much time sorting the combo. Total waste of money and time....... compared to what I got out of my 367 .
Check out TBs post. #15

An interesting conversation for sure.
I went from 17mpg average at 75-80mph with a stock 318 four barrel with headers and a 904 to a mildish 5.9 Magnum and the A500 with lockup (barely ever use lockup and have it turned off most of the time.)
2:73 rear gears and a 25 inch tire.

At that same 75-80mph with the Magnum and A500 I am running right at 2,100 in the rpm's and get 25mpg on the hiway.
My cam is 214/224@50 with a .512 lift and carb is an Edelbrock 1406 (600cfm)
I also run it on the lean side (around 15.5-16:1) and about 18 degrees initial with a total all included timing of 52 degrees or so.

So basically at 75-80 which takes about 1 inch of throttle at the pedal I am running a slightly lean condition and lots of timing.

Now ya got me trying to figure out why some peoples mileage stays the same or even goes down.
I'm about ready to swap in a 3:55 geared A body 8.25 sure grip, so I'm expecting I might be into the throttle a little more out of pure enjoyment, but it will be interesting to see how much mileage I loose.
Don't expect it to be much, but I do expect some loss with an 800 rpm increase at freeway speeds.

Smart cookie that TB
 
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I have never ever been able to get a slanty up to the numbers of a hi-compression 360, even after I took it apart, and boosted the compression up to a true 9.5. And spent way too much time sorting the combo. Total waste of money and time....... compared to what I got out of my 367 .
Check out TBs post.

We've already figured out your 367 is at the top of the heap. Just ask you.
 
32mpgUs,and it was a FTH cam, and it was a 223@.050.. Try to keep up. TBs at
25mpg @75/80mph @2100rpm, how is
32mpg @65 a stretch@1600rpm?
From 25 to 32 is an increase of 28% mpgs, and from 1600 to 2100 is an increase of 31% rpm; I don't see the big deal.
I believe TB cuz I know it can be done.
Like I keep saying; just cuz you can't do it doesn't make it impossible.
 
But AJ, do t you know everybody gets 35+ and 7K tire shredding event’s with there stuff?!?!

Building a mileage master is/was a challenge I always wanted to try.
 
Over the years I've read a lot of posts stating that a larger transmission robs huge amounts of power. I actually read that a C6 takes 60 horsepower away. Here's the flaw in the thinking and observation. A 727 is going to most likely come out of a larger car or a truck. They utilize a lower stall converter. If you put that into a lighter car, it will be slower on takeoff; just like a th400 has a larger converter than a th350, a C6 has a larger converter than a C4. With the same stall, the big trans won't produce a noticeable difference in the seat of the pants; only in a fraction of a second on a time slip.
 
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