f457930 Report post Posted October 13, 2022 I am looking at a coach with this engine. Have heard of problems with it. Any input about it would be appreciated. 650 HP Dee Share this post Link to post Share on other sites
larryanelson Report post Posted October 13, 2022 Dee, I have heard that producing 650HP develops a lot of heat and loves fuel and # 6 piston goes bad. Why do you want that big of engine? l Share this post Link to post Share on other sites
hermanmullins Report post Posted October 13, 2022 (edited) Cummins only made that engine for a couple of years. They had issues from day one and stopped making it all together. Myself, I would run the other way as fast as I could. Herman Edited October 16, 2022 by hermanmullins Share this post Link to post Share on other sites
wildebill308 Report post Posted October 13, 2022 I am with Herman. There are to many people reporting engine failure for me. Do some searches on IRV2 https://www.irv2.com/forums/f123/ I have heard it is a problem with the head dropping valve seats then breaking the valve and destroying the piston. But if having $30,000-$40,000 in repair cost isn't a problem for you. Bill Share this post Link to post Share on other sites
rayin Report post Posted October 13, 2022 (edited) 8 hours ago, hermanmullins said: Cummins only made that engine for a couple of years. They had issues from day one and stopped making it all together. Myself, I would run the other way as fast as could, Herman Right! There;'s a guy on irv2.com who has this engine in his MH. Last I read of his trials and tribulations, he was out-of-pocket $34,000 for 2 engine rebuilds, even after Cummins paid $10,000 on the first rebuild. The 650 HP version was only available in the MH version. The man explained in detail what happened to his ISX, both times. Even on the trucking forums, there are posts detailing semi-tractor ISX failures during the early models. Now the ISX engine MH version is limited to 600 HP I think. Cummins supposedly found the cause of the failures and made corrections. Edited October 13, 2022 by rayin Share this post Link to post Share on other sites
f457930 Report post Posted October 14, 2022 Thanks for the input. About what I expected from the research I have done. I was hoping for the one guy with a positive reply. Maybe a fix for the problem from Cummins. I really like the coach but will most likely heed the advice given here. As for the big engine I thought I might have some drag racing opportunities and being a child of the sixties I wanted the biggest engine. Thanks Dee Share this post Link to post Share on other sites
rayin Report post Posted October 15, 2022 On 10/13/2022 at 9:33 PM, f457930 said: Thanks for the input. About what I expected from the research I have done. I was hoping for the one guy with a positive reply. Maybe a fix for the problem from Cummins. I really like the coach but will most likely heed the advice given here. As for the big engine I thought I might have some drag racing opportunities and being a child of the sixties I wanted the biggest engine. Thanks Dee Cummins does have a "fix" for the ISX, the guy on irv2.com outlined it in one of his posts about 3 years ago. The fix was part of the $34K he spent for rebuilds. All I remember is it involved a new head design, can't remember the rest. Share this post Link to post Share on other sites
five Report post Posted October 15, 2022 The new version of the ISX is 605 HP, with no apparent problems. Share this post Link to post Share on other sites
