Page 2 of 2

Re: Considering buy a aluminum engine

Posted: Mon Oct 26, 2015 11:46 am
by GCRedfisher
DOD is Displacement On Demand, half the cylinders "shut down under light loads to improve fuel economy and VVT is Variable Valve Timing. I know it doesn't mean much but I have a friend with an 07 Suburban with the DOD and that darn things got 200k on it.

Re: Considering buy a aluminum engine

Posted: Mon Oct 26, 2015 12:11 pm
by Jimmy M.
If you find an LS with VVT/DOD you can eliminate it with a delete kit. To eliminate the DOD Summit has a kit for $338 that comes with new valley cover to seal off the DOD towers, lifters, head bolts and lifter trays. If you want to run an after market cam they also have the VVT delete kit that includes a new 1 or 3 bolt cam timing gear, front cover and balanced bolt for about $120.

Re: Considering buy a aluminum engine

Posted: Mon Oct 26, 2015 10:41 pm
by T-REX
DOD and vvt are nothing to be afraid of....... Just understand that
( usually) you'll want( need) to change it back to standard bs.
A few different parts..... Not necessarily 'new dealer' parts....maybe in the future it will be different.

Re: Considering buy a aluminum engine

Posted: Wed Oct 28, 2015 9:38 am
by Waterthunder
If its a 6.2 with DOD or VVT they usually make it to 10 hours before throwing a rod. They do have a 5.3 and other truck motors with the DOD an VVT. The 5.3 is bullet proof in a airboat but most 6.2 motors break the stock cast pistons. Seen this 20 or 30 times now. This number is growing fast. Funny I had a customer get one from a junk yard for 3,500 ofcoarse with under 30k miles. (apparently every engine in every junk yard has less than 30k) He brings it to the shop it has a minimum of 150K on it and someone swamped the sweet L92 heads to 317 casting cathedral port cargo van heads. I hated to see it but he was taken for a ride the motor was so over heated that the bolt holes in the deck were oval. I told him only funny part is the heads they stole off of it were warped overheated junk for sure.

Re: Considering buy a aluminum engine

Posted: Wed Oct 28, 2015 10:51 am
by GeeLeDouche
Waterthunder wrote: The 5.3 is bullet proof in a airboat.


just curious,, What is needed to make a 5.3 bulletproof in an airboat application? Im guessing new cam, springs and valves?

Re: Considering buy a aluminum engine

Posted: Wed Oct 28, 2015 3:03 pm
by jimbo_jwc
So many people go thru the same build trials with Boats w/outdrives thinking Automotive HP is the answer, and all I see them do is talk and work/spend money and time for their HP . Why wouldn't you guys just pick out your favorite Brand in a Marine engine that is already built for HP , Torque and RPM ranges . Then all you have to mess with would be gear reduction and Prop size ,Pitch to maximize thrust ? I think why the Caddy engine works out is because it was built with low end torque to move such a heavy boat on wheels .

PS the guy that owns summit racing up my way didn't become a bazillionare buy selling parts for reliable adequate powered engines ,just go fast so many times and tear down and start over .

Re: Considering buy a aluminum engine

Posted: Wed Oct 28, 2015 5:14 pm
by Waterthunder
I think we got a pretty good handle on airboat motors! Racing or Riding!

Re: Considering buy a aluminum engine

Posted: Wed Oct 28, 2015 5:53 pm
by Deano
jimbo_jwc wrote: . . . the guy that owns summit racing up my way didn't become a bazillionare buy selling parts for reliable adequate powered engines, just go fast so many times and tear down and start over .

So is that to say that their lack of selection that drives Caddy owners to shop elsewhere, is by design ? :D :lol: :lol:

Re: Considering buy a aluminum engine

Posted: Wed Oct 28, 2015 9:01 pm
by jimbo_jwc
Yep light weight materials and Hp per pound makes you want to fly ,most boater friends have luck with truck,suv engines in their mods for their boats and get reliability.

Re: Considering buy a aluminum engine

Posted: Thu Oct 29, 2015 7:51 am
by flying fish
jimbo_jwc wrote:Yep light weight materials and Hp per pound makes you want to fly ,most boater friends have luck with truck,suv engines in their mods for their boats and get reliability.


Are you saying as long as Bud buys an Aluminum truck or SUV engine he will be fine?

Re: Considering buy a aluminum engine

Posted: Thu Oct 29, 2015 1:44 pm
by jimbo_jwc
Not fine but I was referring to Boats with props screwing thru water and fixed gear ratio 15% slip . They usually need to be geared to reach a recommended W.O.T. or the wont last weather aluminum or cast iron engine .

Re: Considering buy a aluminum engine

Posted: Thu Oct 29, 2015 2:58 pm
by DDSBC
jimbo_jwc wrote:Not fine but I was referring to Boats with props screwing thru water and fixed gear ratio 15% slip . They usually need to be geared to reach a recommended W.O.T. or the wont last weather aluminum or cast iron engine .


JAMES is that you? :lol:

Re: Considering buy a aluminum engine

Posted: Thu Oct 29, 2015 5:23 pm
by flying fish
jimbo_jwc wrote:Not fine but I was referring to Boats with props screwing thru water and fixed gear ratio 15% slip . They usually need to be geared to reach a recommended W.O.T. or the wont last weather aluminum or cast iron engine .


Bud is trying to figure out what engine will work for him that also fits his budget. He is geared (reducted) to reach his recommended W.O.T. and has no slippage. Nothing said here about friction loss. Having this no slippage equates to added engine load. This engine load being over 100% at times and if he does his homework, his used, all aluminum engine could possibly last??? To make this experiment work, seems one might need to be very mechanically gifted. ?? Prop load, A/F ratio and EGT'S sure need to be understood. JMO- :)

Buds prop is screwing through the air and this engine Bud will be using has absolutely no idea what is creating/demanding this described engine load.

Buying 3, 4 or even 5 cheaper engines always costs more than buying (1) purpose built "Airboat" engine. Looking back on things, 7 or 8 experiments is much more expensive than (1) purpose built "Airboat" engine.

maybe just a bit of exaggeration? maybe :)

Re: Considering buy a aluminum engine

Posted: Thu Oct 29, 2015 5:40 pm
by Deano
or maybe not . . . :)

Re: Considering buy a aluminum engine

Posted: Wed Nov 04, 2015 2:39 pm
by spencer321
texas speed sells a kit to remove DOD that comes with everything except a new cam and springs I believe, which if your looking for a different kind of grunt from your LS motor, you are going to swap those out anyways. My personal favorite is the L33, but there are a limited number of them as they only came in the HO silverado classic from 2005-2007. However, they are aluminum block, 799 heads which are idential to 243 ls6 heads except for hollow intake and sodium filled exhaust valves. Flat top pistons make almost 10:1 compression, alot of the turbo LS guys putting 700+ to the crank of these with factory long blocks, they can take a beating. And no DOD or VVT to worry about. Just about any LM7 or 3rd gen 5.3 is a great engine. And that truck intake is ugly as hell but a torque monster.

Re: Considering buy a aluminum engine

Posted: Wed Nov 04, 2015 4:50 pm
by Afflicted
flying fish wrote:
jimbo_jwc wrote:Not fine but I was referring to Boats with props screwing thru water and fixed gear ratio 15% slip . They usually need to be geared to reach a recommended W.O.T. or the wont last weather aluminum or cast iron engine .


Bud is trying to figure out what engine will work for him that also fits his budget. He is geared (reducted) to reach his recommended W.O.T. and has no slippage. Nothing said here about friction loss. Having this no slippage equates to added engine load. This engine load being over 100% at times and if he does his homework, his used, all aluminum engine could possibly last??? To make this experiment work, seems one might need to be very mechanically gifted. ?? Prop load, A/F ratio and EGT'S sure need to be understood. JMO- :)

Buds prop is screwing through the air and this engine Bud will be using has absolutely no idea what is creating/demanding this described engine load.

Buying 3, 4 or even 5 cheaper engines always costs more than buying (1) purpose built "Airboat" engine. Looking back on things, 7 or 8 experiments is much more expensive than (1) purpose built "Airboat" engine.

maybe just a bit of exaggeration? maybe :)



Agreed! I had/put more money in a too good to be true engine than I had in the 509MAS when I finally broke down and bought 1. Do it right and it saves money in the long run