andrew383

iTrader: (14)

Is there a point where a higher compression motor would not work for towing?? Or is it all dependent on tuning?? My tuning rite now is no where near the edge and never will be..

Ive got an ls1 with 243 heads rite now so the CR is about 10.5 to 1 but i plan on going 6.0 with the same heads and would like to be 11 to 1 or higher..

Ive got a travel trailer and a jeep that will run about 5500-6500#'s loaded and will pull the travel trailer up 1200 miles at a time a few times a year..

I dont want to build a motor that i have to worry about when pulling either up a 5 mile 6% grade at 70 mph ..


Anyhow input wanted on the subject

skeet

iTrader: (18)

your torque converter is gonna tell the tale.. even at 11.1 you'll be fine with the right torque converter..

1slow01Z71

iTrader: (36)

Might just have to run less timing. If I were you I do an lq4 with your 243s and throw a Radix on top of it when one comes up for q good deal. Na engines just inherently lack tq.

budhayes3

iTrader: (19)

Your cam choice will also come into play...more overlap will bleed off compression and bring your dynamic compression ratio down. Since you're towing though, I'd imagine that your cam choice will be mild and have less overlap, so you're going to have to do the math on that. Anything else that you can do to keep cylinder temps down will help also.

andrew383

iTrader: (14)

Converter will be at 2600 or slightly lower..Im going to talk to Chris @ circle d about maybe using a multi disc to gain more stall speed be locking it way sooner under load..

Thought about it but im against it rite now..I plan on a 125 shot to make it "fast" when i want it to be


Yeah the cam will be fairly small..Ive been looking at some of what isky is putting out in reference to what stock48 was talking about in another thread..

The old tbss pulled the jeep real well but with 4.10's and bolton's it turned some rpms on the hwy lol

The tbss ls2 has 10.9 to 1 and i did notice the engine temp rise 5-10* when i would be in the hills..

All in all is 11 to 1 gonna be safe enough to tow with?

andrew383

iTrader: (14)

Honestly i cant wait to see how it pulls with the current setup.. I make almost 300rwtq @ 2500 rpm rite now..This cam isnt the greatest out there but this truck is a completely different animal from the ol' 5.3
Just hope the stock tranny is feeling up to it

smokeshow

iTrader: (16)

If you have to pull timing due to running a higher compression setup, its going to run hotter. How much hotter, I don't know...you would have to try it and see if you are curious. I don't think I would build a high compression setup and tow with it. The continuous extra towing load on the engine would also load up the cooling system, so I don't doubt you'd have to beef that up too. If you're running E85, then have at it

budhayes3

iTrader: (19)

I'm thinking that 11:1 with a mildish cam will definitely want you to pull timing, which hurts performance, and will probably cancel out the gains you would have gotten from the higher compression. I suppose that you could fool around with spark plug heat ranges if necessary also...personally, if it were me, I'd probably want the SCR around 10.5:1 and get as much timing out of it as possible.

Try playing around with a dynamic compression ratio calculator, using the cam specs that you're considering and different combustion chamber cc's etc, and see what gets you a DCR around 8.5ish:1, as that should be good for a daily driven, hot rod tow truck

If you decide to go with a bumpstick with over 224/22x duration, you'd be more than safe with 11:1, but considering how you plan to use the vehicle, and your 2600 converter, I'm guessing that your cam will somewhat smaller than say a TR224r-112

AKlowriderZ71

iTrader: (22)

Are you gonna use forged or cast pistons? How much of this towing is going to be in the mountains? Besides the weight of the trailer, how heavy is the tow vehicle(when loaded for the trip)?