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-   -   Moving the engine rearward, how far..? (http://www.hotrodders.com/forum/moving-engine-rearward-how-far-226187.html)

Augusto 11-17-2012 06:20 AM

Moving the engine rearward, how far..?
 
Hey guys,

I'm thinking of moving the engine rearwards to better balance the weigth for launching, this a race only 81 ElCamino.

The question is, how much should I move the engine to start making a difference in launching?, I'm thinking of maybe 8 to 10 inches, would this be enough? would it make a difference worth the hassle?

My plan is cutting off the whole firewall and the front part of the floor with it, and welding it back wherever it has to be, this would make fitting pedals and stuff much easier.

thanks for replying.

Augusto.

gearheadslife 11-17-2012 07:01 AM

I'd check with the rules on where you plan on racing this.. (no idea what rules the tracks in s.america have, )
they may limit how much you can . in some classes..
you don't want to get stuck in a 8 sec class with a 12 sec car..

cobalt327 11-17-2012 07:08 AM

There is a lot of math involved to determine the exact changes to moving weight bias rearward but obviously more is better, at least to a point. I doubt you will be able to go too far, though, w/o doing a lot of major reworking to the car.

If this is a drag car, it's interesting to know that raising the center of gravity helps traction by increasing weight transfer to the rear. That's why many early drag cars had a nose up stance and why the altereds had their engines mounted so high. Nowadays, good tires and suspensions (and rules) keep this to a minimum. Whether this is something you could use, depends.

FWIW, in '68 we had a '65 C10 pick up w/a 389 Pontiac mounted 18" rearward. It was the first vehicle (besides our wrecker) that I drove that could pull the front wheels on takeoff. It had other modifications, but the engine moved rearward was the main thing responsible for the added traction.

Irelands child 11-17-2012 07:22 AM

With a vehicle like an El Camino, just be aware of what rearward engine movement will do for leg and foot room and operating the pedals, especially if you are fairly tall. My '31 roadster has a fairly large engine setback and I, at 1.9m, have a tight fit with my feet plus keep knocking the Lokar shifter into 'N' with my knee. My seats, and maintaining a reasonably comfortable incline for driving will not go any further back to help either.

Dave W

69 widetrack 11-17-2012 07:29 AM

Quote:

Originally Posted by Irelands child (Post 1612243)
With a vehicle like an El Camino, just be aware of what rearward engine movement will do for leg and foot room and operating the pedals, especially if you are fairly tall. My '31 roadster has a fairly large engine setback and I, at 1.9m, have a tight fit with my feet plus keep knocking the Lokar shifter into 'N' with my knee. My seats, and maintaining a reasonably comfortable incline for driving will not go any further back to help either.

Dave W

Just to clarify 1.9 meters is roughly, 6 foot 4 inches...your a big boy Dave

Irelands child 11-17-2012 07:35 AM

Quote:

Originally Posted by 69 widetrack (Post 1612245)
Just to clarify 1.9 meters is roughly, 6 foot 4 inches...your a big boy Dave

Yep and along with the 93.2kg settin' weight (depending on how well my wife has fed me that day)

Some of us Suth'ners do know 'metrics' but we mostly have have to do a mental conversion for the rest of the world to understand

Dave W

69 widetrack 11-17-2012 07:51 AM

Quote:

Originally Posted by Irelands child (Post 1612246)
Yep and along with the 93.2kg settin' weight (depending on how well my wife has fed me that day)

Some of us Suth'ners do know 'metrics' but we mostly have have to do a mental conversion for the rest of the world to understand

Dave W

205 lbs...how many stones is that? Just kidding.

Augusto 11-17-2012 08:15 AM

Quote:

Originally Posted by gearheadslife (Post 1612235)
I'd check with the rules on where you plan on racing this.. (no idea what rules the tracks in s.america have, )
they may limit how much you can . in some classes..
you don't want to get stuck in a 8 sec class with a 12 sec car..

no rules..!! run what you brung

gearheadslife 11-17-2012 08:21 AM

Quote:

Originally Posted by Augusto (Post 1612257)
no rules..!! run what you brung


you might want to shift it an 1"-2.5" to the pass side..
it'll give your feet some room and balance out for your body weight left to right

Irelands child 11-17-2012 08:46 AM

Quote:

Originally Posted by 69 widetrack (Post 1612248)
205 lbs...how many stones is that? Just kidding.

14st 9 pounds - geeeeeze. You Nort'ners think all of us here don't know good stuff like that:D

Agusto - don't think you can really shift the engine to the right too much and run generally available headers. Why not just find a huge engine (454 to ???) and install it - lots easier then chopping out a firewall and cobbling up brakes and clutch as well as your leg room. Then there is the problem of just working on the engine and the added time to do simple jobs like adjust valves or even change spark plugs.

Even this is tough to work on:

http://i70.photobucket.com/albums/i8...DSC_0076-2.jpg

69 widetrack 11-17-2012 08:52 AM

Quote:

Originally Posted by Irelands child (Post 1612265)
14st 9 pounds - geeeeeze. You Nort'ners think all of us here don't know good stuff like that:D

Don't want to take away time from the guy wanting to move his engine back, but, the stone thing...I would have had to look it up on the internet.

OneMoreTime 11-17-2012 09:13 AM

Back to the original question..As far back as you can get the engine and still have legroom in that car..

Sam

poncho62 11-17-2012 09:24 AM

Dave...We Canadians must be getting to you with the metric and all.....Move away from the border.....lol

1 stone =20 pounds, I believe.........I learned that many fortnights ago

69 widetrack 11-17-2012 09:32 AM

"(depending on how well my wife has fed me that day)"

Hey Poncho...Maybe his wife fed him real good before he stepped on the "stone scale", sorry Dave, I couldn't resist, I wouldn't know the difference in weight between a stone and a rock.

Ray

Augusto 11-17-2012 09:42 AM

Quote:

Originally Posted by cobalt327 (Post 1612237)
There is a lot of math involved to determine the exact changes to moving weight bias rearward but obviously more is better, at least to a point. I doubt you will be able to go too far, though, w/o doing a lot of major reworking to the car.

If this is a drag car, it's interesting to know that raising the center of gravity helps traction by increasing weight transfer to the rear. That's why many early drag cars had a nose up stance and why the altereds had their engines mounted so high. Nowadays, good tires and suspensions (and rules) keep this to a minimum. Whether this is something you could use, depends.

FWIW, in '68 we had a '65 C10 pick up w/a 389 Pontiac mounted 18" rearward. It was the first vehicle (besides our wrecker) that I drove that could pull the front wheels on takeoff. It had other modifications, but the engine moved rearward was the main thing responsible for the added traction.

you are right, I have not considered this, maybe I should also raise the engine something like 4 inches or so, will have to pay attention to the rear pinion angle.

I don't mind doing a complete reworking of the car, I have a body shop and deal with this kind of stuff everyday.

there's plenty of room to move the seat rearwards while keeping the driver's space about the same size, and being 5'7 is and advantage this time :D


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