525 sc's
#11
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Join Date: Sep 2010
Location: The Woodlands, TX
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At a minimum, the top ends and the blowers should be done. The top ends are way overdue. The blowers were and issue and should be freshened, especially if they haven't been serviced on a regular basis. I would send them to DMPE instead of The Blower Shop. They do excellent work and are less than TBS.
Eddie
Eddie
At a seat of the pants guess, do you think a roller cam, lifters, rockers, springs, and a blower rebuild would go over 10k for both motors? Or would I be better off leaving the cam and replacing the lifters, rockers and springs. I don't think these motors were a full roller set up when they were built were they.
I did kind of feel that I'd get the responses you guys gave me.
I was just wishfully hoping that I'd see 600+ hours prior to a major investment on the valvetrain and the blower.
I always thought these blowers didn't produce boost until over 4000rpm and you could expect a reasonably long service life from the factory setup. I certainly didn't expect 1200 hours but thought 700 might be within reach.
I'm really on the edge here, the boat is truly priced right, very clean, and I do like the idea of having some better performance in the higher RPM's.
But, I've also found that patience is everything. For every boat that I've thought was the one initially, after further research and passing, another excellent unit has came on the market within several weeks to a month later.
Thanks for all of y'alls insight.
See ya,
Kelly
#14
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Yes, you can certainly do it under 10k. You are right that it's not a roller engine. It is also a 454, not a 502.
The blowers were a hit and miss. Some lasted forever, and others did not. The blower rebuild is just preventative maintenance. The best thing to do for the blower is to service it religiously.
If you are going to change the cam, then I would absolutely go with a hyd. roller. The flat tappets of today are having some issues. There are a bunch of cheap lifters from oversees combined with the lack of zinc in oil. Sure, you can use additives to replace the zinc, but why bother. Put in a hyd. roller and be done with it.
Give me a shout if I can help in any way.
Eddie
The blowers were a hit and miss. Some lasted forever, and others did not. The blower rebuild is just preventative maintenance. The best thing to do for the blower is to service it religiously.
If you are going to change the cam, then I would absolutely go with a hyd. roller. The flat tappets of today are having some issues. There are a bunch of cheap lifters from oversees combined with the lack of zinc in oil. Sure, you can use additives to replace the zinc, but why bother. Put in a hyd. roller and be done with it.
Give me a shout if I can help in any way.
Eddie
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#17
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Just noticed that. They are intercooled. You can see it in the second pic on page 1. Wonder if the pulleys were changed.
Eddie
#18
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I just noticed the chillers also.
The stock pulley diameter is 3.5" upper and 7" lower. The stock boost is 5.5#. They will start making boost in the 3500rpm range.
They are not roller cam engines but do have roller rockers. A good off the shelf roller cam is a Crane 168731 and its an easy conversion, but will cost you about an extra $1200 per engine to do. That is the cam I put in my 525SC. I was also running about 7.5# of boost without a chiller.
Be advised that you need 92 octane fuel and the 525SC's are very thristy.
The stock pulley diameter is 3.5" upper and 7" lower. The stock boost is 5.5#. They will start making boost in the 3500rpm range.
They are not roller cam engines but do have roller rockers. A good off the shelf roller cam is a Crane 168731 and its an easy conversion, but will cost you about an extra $1200 per engine to do. That is the cam I put in my 525SC. I was also running about 7.5# of boost without a chiller.
Be advised that you need 92 octane fuel and the 525SC's are very thristy.