Summit LM7 Crate Engine replacement

[leprekhan]

Thank you all for the hours I've spent reading everyone's experience and expertise on this forum. I haven't posted much but feel I need some help with an engine swap/rebuild. I bought a 2010 Hoe with the LMG engine w/100k miles on it about 4 years ago. It's got 165k now. I recently Bought a boat(5,000LB) and had to trailer it from NC to MD. Trailering home, my truck never got out of 4th gear on I-95 and at best, I got 8mpg. Needless to say, she's lost a lot of power. I'm thinking of having the engine replaced. I have the knowledge and tools to do it myself but don't have the space or time. I'm either going to buy a rebuilt LMG short block and get a Texas Speed head/cam package. With AFM/VVT delete and new torque converter, that will run me about $5k (+labor to install). I just saw this Summit LM7 crate engine(450hp) completely assembled for $3700. Anyone know if this will swap out for my LMG? Any differences that I'll have to account for? Apologies if this has been addressed elsewhere. I didn't find anything. Thanks in advance.

 

[swathdiver]

Thank you all for the hours I've spent reading everyone's experience and expertise on this forum. I haven't posted much but feel I need some help with an engine swap/rebuild. I bought a 2010 Hoe with the LMG engine w/100k miles on it about 4 years ago. It's got 165k now. I recently Bought a boat(5,000LB) and had to trailer it from NC to MD. Trailering home, my truck never got out of 4th gear on I-95 and at best, I got 8mpg. Needless to say, she's lost a lot of power. I'm thinking of having the engine replaced. I have the knowledge and tools to do it myself but don't have the space or time. I'm either going to buy a rebuilt LMG short block and get a Texas Speed head/cam package. With AFM/VVT delete and new torque converter, that will run me about $5k (+labor to install). I just saw this Summit LM7 crate engine(450hp) completely assembled for $3700. Anyone know if this will swap out for my LMG? Any differences that I'll have to account for? Apologies if this has been addressed elsewhere. I didn't find anything. Thanks in advance.

LM7 is a Gen III engine. Wiring and crankshaft reluctors are different but they do make adapters. Your engine is better, stronger.

Do a leakdown or compression test to see what kind of pressure the cylinders are making. Then you'll know if you have a good block or not. Fresh heads and new camshaft and valvetrain and she would be near as good as new for another 100K.

 

[leprekhan]

LM7 is a Gen III engine. Wiring and crankshaft reluctors are different but they do make adapters. Your engine is better, stronger.

Do a leakdown or compression test to see what kind of pressure the cylinders are making. Then you'll know if you have a good block or not. Fresh heads and new camshaft and valvetrain and she would be near as good as new for another 100K.

I will definitely do that. Thanks for the help.

 

[rockola1971]

I will definitely do that. Thanks for the help.

Yes you can save yourself a whole engine replacement and cost by ruling out low compression, stuck lifter, leaking valve, ignition system fault and host of whole lot of other things. Is it throwing and codes? Flashing the CEL at you?

 

[leprekhan]

No codes/errors, runs fine, although feels weak at times. But does lose coolant from somewhere. Have to top off the Dexcool every few months.

 

[leprekhan]

I'm also concerned about torque converter failure with so many miles on it and now asking it to tow 5,000lbs.