BIG LESSON LEARNED

[top dog]

as most of you know by now i bought my 89 fbc in oct.2006 you guys have helped me alot here. I was planning to do my risers& manifolds on my 454's with 700 hrs.only , after this summer having the understanding from the original owner that they were done two years ago, well long story short, i had a noise in my trany and after it was checked the techs at mti in ft. lauderdale (EXCELLENT GUYS) they told me the trany was fine,they send check firing order, check wires and engine, well my compression was 35 thru 135 in my engine and that sucker ran AWSOME my risers had a little hole that was sending water in my engine for who knows how long, well i will be out for about a week while my engine gets rebuilt i know all of you know better but this is a story for any rookie out there like me these 454's can run strong and they are realy dying...Pete

[franklyprice]

Pete, I had a similar pronlem with mine when I bought it from the same problem. It's a piss poor design on the manifold/riser. When I took my heads off the cylinders looked like new, no problems at all. The heads were pretty rough because the valve seats are not hardened. What happens is the face of the valve gets rusty and since iron oxide is hard as hell, it wears the face of the valve seat down. The fix for my boat was as simple as having a machine shop install hardened seats and give the valves a grind, not one needed replacing. I would bet that yours is the same. P. S. I knew this going into the boat because I did a compression check before I bouhgt it, gambled a little bit on how much work it would need but it worked out OK.

[captgene]

An all familiar story. Fortunatly I had some experence with the Mercs prior to the Bertram. I changed the risers every two years, and I changed the exhaust manafolds when I bought it. Compression checked it every Jan. when I had time. When I yanked those 454's out they had over 2000 hrs and compression was still 135-140 on all cylinders. Hopefully the new Crusaders will be even better. At least I can take somewhat of a rest , and use the boat before I have fix anything. Gene Dugan Boca Raton, Fl. "Nauti Marie" 1989 33 FBC

[top dog]

i feel better now knowing i was not alone. Should i change both the risers and manifolds every two years or the isers only??

[Miss B]

The problem is the manifold to riser gasket surface area. In the split between the exhaust gases and the water passages, the gasket fits over a very narrow boss surface area and the design allows water to leak in to the manifold passages. Mercruiser has a "dry joint" version for its small block GMC engines, but nothing yet for the big block versions. In the small block, there is a block off plate between riser and manifold, and the water is plumbed into the riser by separate hose, rather than through a combination exhaust and raw water manifold connection. If you start to see rust on the exterior of your riser to manifold conection, it is time to replace the gasket. You can get by by doing this every two years if you keep a close eye on it.

[captgene]

I would replace the risers every 2-3 yrs. 2005 I had a problem that took me a couple overheats to figure out. The risers were only 1 yr old. The manifold on the outboard Port engine had a pinhole that leaked coolant down into the back cylinder. When I finally figured it out, I'd replaced the heatexchanger for the 2nd time and coolant was still going down. I started blocking off hoses and put a radiator pressure tester on the heatexchanger. Finally , I knew the problem was on the Port side. Pulled the back plug and coolant ran out. Lucky for me there was no damage. Ran the boat another year. But I knew time was running out and repowered. I had made 2 trips half way to Bimini and overheated at the 25-30 mile point. So check you manifolds. No need to replace them more than once if they arn't rawwater cooled. Unless you get another 1500 hrs out of those 454s. Gene Dugan Boca Raton, Fl. "Nauti Marie" 1989 33 FBC

[top dog]

thanx guys i just wanted to be sure how often to change these guys,90 percent of my boating is a 1 hr. round trip from my marina to elliot key and back and i only fished for 8 hrs. so far this summer so its not like ill be putting on major hrs. and my engines only have 700 hrs.....Pete

[dougl33]

When I had my gas motors, I would replace my elbows every 5 years. Never had a problem with them running hot. Regards, Doug L. 1986 33 Bertram FBC Queen Elizabeth Marblehead, MA [img]http://www.bertram33.com/photogallery/p ... sabeth.jpg[/img]

[skyking]

Hi Guys, I canged my original Crusader manifolds about 8 years ago and have never had a problem w/either the old or new ones.(Granted I put very few hours on the engines) After every use I flush both engines w/fresh water (engines are fresh water cooled). I installed a garden hose connection just inboat of the raw water strainers. Back "BC" into her slip, keep engines running, connect garden hose, turn on hose then close raw water valve. After running one engine for about 10 mins. I shut that engine down and switch to other engine, repeat process. I feel this is agreat way to flush your tranny cooler, engine oil cooler, heat exchanger, and exhaust risers. Any coments would be greatly apperciated....thanks Ken AIM: skyking4ever + 3 hrs. EST

[Miss B]

Skyking, the design of the Crusader manifolds and risers is superior to the Mercruiser design. In the old style Crusader's the raw water is injected at the end of the exhaust manifold directly at the riser, and not in the middle of the exhaust system like Mercruiser. The mounting bosses are more than four times the width of the Mercs, and because of that the gasket system forms a positive seal to prevent raw water leaking back into the exhaust passages.

[skyking]

Tom, Thanks for the reply.....well I'm glad to hear the Crusader exhaust is a good design. I visit Sarasota fairly often, friends boat was at Marina Jack's in downtown, would like to stop by some time, say hello and see your boat if possible. Thanks again Ken AIM: skyking4ever + 3 hrs. EST