Hi, my 36OL now has 200 hours total on the 525EFI's. Like most 525's they suffered numerous header failures in the early days so each has at least 3 rebuilds on it. The latest was one last year with a thrown valve. So, I figured this winter would be the perfect time to freshen them up and do a few upgrades as they are officially 10 years old now. Quite a sad state of affairs that I only put on 200 hours in 10 years. As part of this thread I am going to post a ton of pics and info on the various upgrades I am including for thos who are interested. Here is a quick run-down of the upgrades I am hoping to do:

1. AFR CNC work on heads - larger & lighter valves, springs, etc.
2. Camshaft swap
3. ECU flash
4. Carbon fiber valve covers
5. Fresh paint and powder coat
6. Updated ECU/Coil mouting plate
7. Updated Power Steering Reservoir
8. New alternators / relocate to top left like new 8.2
9. New serp belt tensioner like new 8.2
10. Relocate oil fiter to right rear off of cylinder head
11. New aluminum catch can
12. Relocate mercathode to transom - use Red dual feed one
13. New double bilge pumps
14. Improved fuel and water lines
15. Relocate fuel filer from under engine to top
16. New better starters
17. Clean up wiring harness

I'm ears open for anyone who has played with any of these ideas of has any other suggestions. I am starting with one engine and once that is 100%, I'll do the other. So off we go....

Here is the engine before... it has not been running right for the past few years and no one can figure out why. It scans fine and everything checks out fine, but it is way down on power.


Ok, the engine is stripped down, no smoking gun yet. All of the pistons and valves are intact. It is going off to the machine shop to dissasemble. They are going to check the cam timing, a possible cause of the lack of power, and blueprint it. Plus new bearings and rings.


Here is one of the heads being disassembled. The new LSM valve tool is SOOOOO nice to use.


The heads after disassebly and degreasing. There is a fair amount of carbon buildup in the combustion chamber, probably from the factory tuning which is a bit rich, even on 87 octane.

Enjoying the pix and your experience.

Close up of the chanber. You can see the heavy carbon and some rust. The new valves will be stainless which will help. I upgraded the other motor to Manley Extreme SS valves last year, too bad they are going for the new bigger ones. The rust around the valve seat may be part of the slight revesion problem. You can see some salt in the exhaust runner.


Pistons look pretty good.


Worst of the exhaust ports. Not actually as bas as it looks as there is still a lot of gasket material on here. Definitely some erosion from reversion and header leaks over the years.


Did find this problem... one of the intake runners has lost part of the o-ring and had a little bleed by. Doubt this really effected it too much. Thoughts???


The coils don't look bad. One pin was a bit rusty. I am going to repalce all of them as I found what I believe to be a match in the Isuzu Amigo and Rodeo early 2000's. Stay tuned on this one.


Cleaing up the raw water hoses so I can make some decisions on what needs to get replaced.


That's it for this weekend. Stay tuned for more....

Love a detailed pic build.

Ed, do you actually do any real work, while your working?
-Harry

ps go take off my flywheel so we can separate the ring gear lol

Do you want to sell closed cooling parts? I also need alternator PS pump and oil cooler.
Thanks
Steve

I will sell the closed cooling tank, not the exchanger, if my plan for an alternate at the back of the engine works. Alternators I am going to replace, they were rebuilt last year. PS and oil cooler are staying. PM me.

More work coming this weekend.

what do you mean by running poorly?

Started and idled perfectly, ran great up to about 3500 then started to take more throttle than the other engine. At full throttle it was about 500-600 rpm short. It I ran it at full, I could run the other at maybe 2/3 and they would be even. I was down about 7 mph for most of the last 3 years, unable to diagnose the problem. Neither could the local Merc Platinum dealer. Last plan was to send it back to Merc for them to figure out. Towards the end of this season it started to give me a little more of a hunt hn it would start stumbling while cruising at 4000. It would drop to 3600 or so for a few seconds then surge back. Screams electronics to me. No codes, nothing on data logs, just a ghost. On this weekends list is to pull the intake apart so I can send out the injectors to be blueprinted.