Thread: SHO/FZR/FZS Blown up Engines!
11-10-2011, 08:21 PM #1
- Join Date
- Jul 2005
- Central North Carolina
SHO/FZR/FZS Blown up Engines!
I seem to see a pattern developing. More and more motors with broken engine internal parts. I think the reason most of these motors fail is that the oem pistons and or connecting rods are breaking apart from more boost pressure than these cast pistons and or connecting rods can take over time. Now I see 24 psi SC wheels coming out ( wow). I have been keeping track of engine problems on these skis for two years now and it seems to me ( my opinion only and not guaranteed to be safe) that 12-14 psi boost and 8400-8500 rpms is the max. oem internal pistons and rods can take for any extended period of time. If any of you deside to go beyond these limits I suggest you go with good after market rods, pistons , valve springs and other associated parts as required. I just hate to see or here of more broken engines showing up when these problems can be avoided if some good guide lines on what is required for more boost and rpms was followed. Even then there is no guarantee you won't suffer a major engine failer but at least the odds are in your favor if good aftermarket parts are used. Tommy Jordan
Last edited by 2fast4u; 11-18-2011 at 09:01 PM.
11-10-2011, 08:55 PM #2
I agree Tommy. I think your range of safe boost and RPM for stock internals/valve train is SPOT ON. I had thoughts of going 1.9 liter this winter but until there are reflashes available to support that level of modification I'm not too crazy about it. Think I'll try and get one more season out of my stock motor before cracking the engine open. Going to do custom cams + custom reflash + an R&D/Skat pump and shoot for 84-85 with my little ole C3 wheel.
If I hit 250 hrs on my stock motor SHO this coming season I think that will be a true testament to the readability of mid level of boost and the reflashes. So glad I made the decision to purchase my SHO back in 08. Have never regretted it for one minute.
11-11-2011, 12:26 AM #3
this brings up good point about oem internals.
last year i ran with a C3/R2 setup running 8400 to 8600 rpms. no problems, then i dropped in a C5 with the R3 flash and i melted the rings on the #2 piston. lesson learned, know i have the riva internals upgrade with a AFR gauge and a boost gauge.
a friend of mine was running a R3/C3 setup and snapped the con-rod on the #2 in september. he was only running 8200 to 8400 rpms.....
i do believe that it is recommended that you upgrade the internals if you are going to run over 8k rpms.
11-11-2011, 10:38 AM #4
most of the engines that ive seen or heard of blowing up have blown the #2 and #3 cylinder/piston.
does anyone know of or heard of anyone blowing #1 or #4 cyl ?? sorry if i missed it in any other blown engine thread.
11-12-2011, 12:04 PM #5
2 stock legal Closed Course ski's ( JE Pistons with Oem connection rods) with motec ...
Past his limit with to agressive tuned Motec...
After that rebuild with Carrillo Rods and JE pistons (No more Stock Legal) without any further failures..
11-12-2011, 10:08 PM #6
- Join Date
- Aug 2008
- Southern Florida
11-14-2011, 09:37 PM #7
so for you guys that are running higher boost and RPM`s what have you done to your short block to make it bullet proof, Pistons, rods? and is there a options for the cranks dont remember seeing much about crank failure and are any of you guys running sleeves?
11-14-2011, 09:50 PM #8
11-28-2011, 05:11 PM #9
ok you guys have got me worried , I was wondering if anyone had any input on my set up im running an r3 with a c1 the rest you can see at the bottom of the page my rev limiter is set at 8850 but probably turning about 8200 8400 (tach on the todo list) im safe right?
11-28-2011, 05:23 PM #10
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By ksalles in forum Conversion PWC Performance SkisReplies: 3Last Post: 08-24-2011, 04:51 PM
By JIM'S PERFORMANCE in forum Yamaha ClassifiedsReplies: 7Last Post: 08-12-2011, 08:51 AM
By wave15stx in forum Yamaha ClassifiedsReplies: 1Last Post: 04-17-2011, 07:49 PM
By SpeedJunky in forum Yamaha ClassifiedsReplies: 4Last Post: 12-02-2010, 03:45 PM
By Green Hulk in forum Conversion Skis ClassifiedsReplies: 12Last Post: 01-13-2010, 08:28 PM