rebuild... how much?
 

I'm looking for a ballpark estimate of what it cost to rebuild a pair of carbed 454 mags (4th gens - both currently installed in the boat) with 500 hours on them assuming this is the first rebuild and no out of the ordinary problems arise. I've looked all over the internet and all through these forums and cant find a straight forward answer to my question (sorry if this is a a topic that has been covered in another thread somewhere). I dont want to do anything "special". I just want to keep it simple and very reliable. I'm in the Kansas City area if anyone wants to vouch for a shop within 100 miles or so.

Thanks in advance...

average is 3k per motor.

add another 2k - 3k to the project if you replace external things.....caps/rotors/wires/plugs, seawater pump rebuilds, sending units/sensors, rebuild carbs, etc.

Are you removing and reinstalling the engines yourself???? If not, figure about $1200 for that as well.

I would estimate 3-4k each engine for stock rebuilds, but a lot will depend on what parts are needed. Take it down to LOTO. Performance Boat Brokerage can handle this easily and they use Lake Ozark Speed and Marine for the machine work. They both stand behind their work.
It will also be slowing down for both of them over the winter.

I'm in the Kansas City area if anyone wants to vouch for a shop within 100 miles or so.

R&R Motorsports in Benton, IL. has done my machine work for about 15 years. Does quality work at fair prices.

If the engines are running fine, and not consuming oil and what not, i'd probably do a leakdown test. Carbed 454 mags can probably go a couple more hundred hours if they were maintained properly. My buddy had a pair with 900+ hours and still ran strong.

I agree, if there are no problems and they are sound you should still have about 50% life left in your engine. I am at 650 hours on 502 mags that run as good as they did at 200 hours.

Thanks for the advice/info everyone... looks like I'll be taking it to performance boat brokerage if I can come up with the money. Its pricier than I had hoped. Wish me luck, I'm gonna be saving my pennies to hopefully get this done before the spring rush.

I pulled my 454/300s (twins) myself. Had 2k in machine work and a lot of that was above and beyond a normal rebuild. One new block at 350. One set of 049 heads to match the other ones 350. Two rochester rebuild kits 60, two new impellers 80. Had 1800 in rebuild kits from Maddog including cams one new crank and new pistons, and probably another 500 in misc bs. I assembled them myself and put them back in myself.
So at a MINIMUM you are looking at 5K for both and add another 750-1k to have someone else assemble them(each), plus some more for install. I think around here the average is around 4-5k per motor having someone else do it all.
I'd probably run them some more too if the leakdown is good.

I know of a stock 454, Gen IV, with 900 hours on it. It was pulled and replaced from that boat, and put into another 3 years ago. Not sure how many hours are on it now but it still gets out of the hole and spins up to 4800 rpm rather quickly.

+1 for PBB. I know first hand that they stand behind there work. They did my 502's last winter had an issue and they had it taken care of in a week and even launched the boat and put it back on my lift for me when it was all finished. Most shops would have tried to shake me down for more coin, but they simply apologized for the inconvenience and said they look forward to my future business.

Most shops claim to warranty their work but when push comes to shove you get a fat invoice and are saying WTF.. You get what you pay for and PBB Customer Service Can't be beat.

Yeah, make sure you NEED a rebuild before you burn up your wallet.

454/330hp motors will go a LONG time if maintained well.

Now, your signature shows a 1994 model year boat. If your motors are 1994 model, they are likely NOT MkIV motors, which were phased out in 1990/1991. Some boats got leftover MkIV's into the 1992 model year, but I've not seen them factory-installed in a 1994.

That doesn't really affect the rebuild cost, though.

MC

+ unknown expenses
 

Just to start pulling and reinstalling in addition to other labor charges such as refresh rebuild with the existing parts and machine shop charges, IMO your looking at 4K to 5K per motor. But, there are hidden potential expenses like coupler condition, Gimbal bearing condition and shop supplies. Once you have the motors disassembled, there is no telling what the condition of the existing parts are. The charges can really add up quick. Shop estimates are sometimes not even close. For the cost of rebuilding the Merc motors with the same old and tired parts, you may want to find a good performance motor with the latest performance parts.

Check out the folks of Patriot Performance Engines and speak to Chad Bowling
888-462-8276
https://www.patriot-performance.com/
I was told they build performance marine engines and produce their own line in house CNC aluminum cylinder heads.

Messing with the old motors may not be worth the cost??

Why do you need to rebuild? Are they burning oil, loss of power/compression. If running fine, 500 hours is not excessive if oil changes were done consistently. Plenty of motors running to the 900 to 1k hours mark.

If you're heading down to LOTO area, make sure you stop by and see Gene at Lightning Performance. He has done several motors for OSO folks (including mine). He does everything from basic rebuilds to 1500HP+ custom motors (95% of his work is marine motors but he does occassionaly build a beastly street motor). He is very meticuloous and precise about his work and it shows in the quality and reliability of his finished products.

If nothing else, it's worth a phone call to chat with him. He is a straight shooter and will give you some sound advice. From there you can make an informed decision.

Gene - 573-374-7974

i have 4500 in mine and i removed/installed. a local builder did mine top to bottom. we didn't reuse anything but the block. my motor was pretty well hosed, so we did pistons, rods, crank, cam, bearings, top end w/rebuilt 271 heads (found there were peanut port heads on it once we got it apart so rebuilt some cores my builder had). did it with a few mild goodies. pretty much made it ~400hp for a mild, reliable motor.