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Same engiine with camshaft change to my Duramax cam. It is smaller than the OEM profile, but the valve events have been fixed....runs an average of 250 degrees cooler on EGT's, spools the turbo 800 rpm quicker....worst we have seen in gas mileage increase is 22%.....

Duramax 2.5 Pulling Class...... With SoCal cam and heads....

Morel functions like an OEM, they have a limited dealer network. We don't call GM and order a new HD2500. Because of this, some engine builder ego's get crushed and they bad mouth Morel. I have been told point blank by a well known builder...won't use them because they won't sell me direct...

Early AFR castings did not have any additional holes to vent the heads to lifter valley. We made AFR aware of this and they now drill holes in the center of the heads to vent the valve cover area to the lifter valley. If not done this can lead to oiling issues. Sorry I didn't see this.

That's an early set of heads that is not vented.....need to vent the heads.

AFR heads have a very high I/E ratio. A single pattern or a mild split works the best. Cam was optimal for OEM heads, it was blowing power out the exhaust with the AFR heads.

Anytime you see more lift on the exhaust these days, that cam profile is dated 40 year old thinking. Modern day cylinder heads have come a long way since the 70's and 80's. They flow a ton of air quickly. Today's heads flow the same cfm at .300" as heads of the by gone years did and .500 and...

Pushing the stick forward on old 29' Fever I could cavitate the prop and blow it out pretty easy. 525EFI with a 26P. Not so much now with Bravo 3 and 8.1. MSD rev limit set at 6000 rpm.....MSD chips start to drop cylinders 300 rpm below what the chip states. That would be 5700. Its never...

My friend that worked for another cam company that was based in FL called and said. It's been over revved at some point and broke the tie bars. He said with the time on the lifters it has probably been over revved over the years, it is a boat he said. The rivets have been fatigued with that...

Thank you and will do.

You've got some "Star" pattern on the tips so its floating. How wide is that pattern? All that harmonics is transferred to the lifter. What had the seat pressure dropped to when you changed the springs out? Again there is no load on the tie bars, so in normal operation their is no stress...

When you say you have 200# seat pressure is that confirm as the heads are now, or when it was new? Take a picture of the tip of the valve. Does it have a star pattern? Check pushrods for marks on them in the area of the pushrod that goes through the heads.

I would build for what gas you can buy at the marina where you boat. That way you don't have any worries if its been a good day on the lake and you need fuel.

Yes it's Chris Straub. Somebody FB messaged me to alert me to this thread.

If having issues its usually pre-load, lifter to bore clearance, or oil centistoke rating. The Driven FR50 works great with the lifter in a marine enviroment.

It's not lifter failure...its lifter abuse due to an unhappy valvetrain. Tie bars have not load on them...they are just a guide to start the lifter and aid in tracking. If you have broken tie bars you have an issue in the valvetrain. Heads need to come off and be checked. If you want to send...