Advice For Engine For Towing

View previous topic View next topic Go down

Advice For Engine For Towing

Post  plowboy34 on Sun 7 May 2017 - 8:32

I built the last engine by doing a lot of reading and not asking any questions and the engine ran fine and did pull like a freight train. I figure this time I would ask questions.

This engine is not for racing just strictly towing a 5th wheel camper trailer. It will be lucky if it is ever over 4,500 rpm.

It is an 86 truck engine that is bone stock as of now, I will be running a set of D3 heads that have been ported on the exhaust side and will be running longtube headers and dual exhaust. It will have a Edelbrock performer dual plane intake. I have heard bumping the compression will help mpg but I do not know. The last engine had a decent cam, I can't remember the exact specs but I do remember the lift was 480 on both sides. I know the old man isn't going to want the dash bouncing when at idle so we can't go to crazy with that. Just wondering what you guys would recommend, just remember I would like to keep this on 87 octane. Thanks

plowboy34

Posts : 220
Join date : 2010-03-12
Location : SE Missouri

View user profile

Back to top Go down

Re: Advice For Engine For Towing

Post  DanE on Sun 7 May 2017 - 9:54

You do not want a lot of compression if you are going to work the engine hard as in towing.
The stock intake will out torque other intakes up to 3000 RPM or so.
The "Street Demon" 625 CFM carburetor would work well here.
Stock valve size, good valve job, blend valve job into bowls.
CC combustion chambers to factory specs.
Bore block .030" and use factory replacement pistons or equivalent.
Deck block to top of pistons. Use .040" +/- head gasket.
That should get the engine in the 8 to 1 / 8.5 to 1 compression range.
Use factory cam or a custom cam to maximize torque from idle to 4500RPM
FPA mid length headers would work well here.
2 1/2" exhaust pipes, "H" pipe, straight thru mufflers, and tail pipes to the bumper.
Install an advance curve into the distributor using an 11 degree shoe all in at about 2500 RPM and 16 degrees initial timing for a total of 38 degrees. 10 degree vacuum advance.

And of course, if there is a budget for it, increase stroke.

DanE

Posts : 72
Join date : 2010-04-01

View user profile

Back to top Go down

Re: Advice For Engine For Towing

Post  rmcomprandy on Sun 7 May 2017 - 10:35

Use as much compression ratio as probable with iron heads when using 87 octane pump gas ... at sea level, with a zero deck and active quench, this is usually slightly over 9/1 with a 460 size engine having suitable valve timing.
The Federal Mogul O.E.M. replacement pistons with metric rings as used in the older FRPP crate motors work well at zero deck; #H612P.

Get a custom hydraulic flat tappet camshaft with relatively short duration and enough overlap to get good mileage & performance when going down the highway at PART throttle situations.

I would use a custom QuadraJet carb but, the "Street Demon" is a good choice, out of the box.


rmcomprandy

Posts : 4724
Join date : 2008-12-02
Location : Roseville, Michigan

View user profile http://www.rmcompetition.com

Back to top Go down

Re: Advice For Engine For Towing

Post  The Mad Porter on Sun 7 May 2017 - 14:01

We recently did a towing specific build. Just a bit over 9 to 1 static. 553 tq and 430 hp @ 4,800.
We've done several of these with good results. High altitude versions get more static c/r.

Take a look and feel free to use the build as a guide:

https://www.facebook.com/pg/SMJRHP/photos/?tab=album&album_id=1303851559702227





S
avatar
The Mad Porter

Posts : 174
Join date : 2009-08-07
Age : 54
Location : Tacoma, Washington

View user profile http://www.reincarnation-automotive.com

Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum