Engine Block cracked. Need Help
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=1835
Printed Date: November-22-2024 at 8:07pm
Topic: Engine Block cracked. Need Help
Posted By: Andrew McBride
Subject: Engine Block cracked. Need Help
Date Posted: June-08-2005 at 3:35am
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I bought a 83' Ski nautique few months ago knowing there was some engine work needed to be done. Bad luck though, a head and the block was cracked. I am no mechanic by any means.
My question is...is there a difference between a Marine 351W vs. a reg. 351W. Obviously the cooling system in completly different. I have been told so many different things: "The marine blocks have thicker walls, the gaskets are different, there is no difference." I want to just make sure and get this strait. I am going to have to find another block and another head, have the motor re-worked and machined. Any help would be greatly appreciated. Great site by the way, really enjoy the posts on this forum Andrew ------------- Andrew McBride 83' Ski Nautique "Under Construction" |
Replies:
Posted By: AWhite70
Date Posted: June-08-2005 at 12:02pm
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I assume you're asking about the block and heads specifically, not the entire engine.
You're engine is reverse rotation (RH-spins clockwise when standing behind the engine looking forward) because of this your cam, crank, distributor gear, starter rear main seal and front cover seal are RH specific. An automotive engine spinst in the opposite direction (LH) With that said I am 99% sure you could use a standard automotive block and head. A few things to be careful of. With the head either buy a set or make sure the new head has the same specs has the old head (i.e. valve size and combustion chamber geometry) or your performance will be different on each bank. Additionally you may need to plug the ports in the head for emissions controls on automotive heads. As for the block, a standard block should work but you'll want to make sure all of the engine mounts and accessory mounts line up. I'm not sure if these were ever changed over the years or not. |
Posted By: Bob's2001
Date Posted: June-09-2005 at 9:38pm
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Many of the engine exchange companies have marine engines. A friend of mine bought a marine 350 Chevy long block from Thunderbolt in Houston for $1200. ------------- Bob Ed 83 2001 |
Posted By: cshire
Date Posted: June-11-2005 at 7:32pm
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a standard automotive block will work. Just switch over all the internals off your engine.
Ford 351's had many small changes over the years. Your safest option is to match block casting numbers to assure compatibility. The block casting number is located on the lower portion of the block under where the starter mounts. The casting number is virtually impossible to see when the engine is in the boat boat is easy to find if you put the engine on a stand and rotate it upside down. Match head castings as well to ensure compatibility. If you are not a mechanic take your current engine and new block to a reliable rebuilder. they will be able to reassemble new engine and let you know what if any parts need replaced or machine work needs to be done. Just make sure they don't try to talk you into too many "hot rod" performance upgrades. They may help performance, but will drive up your cost. Surf some of the mustang and ford performance websites and discussion boards. They will have a lot more specific engine information about rebuilds, parts interchangeablilty, etc. Just remember to them high rpm horsepower is the goal. Your goal is probably a reliable engine so you can ski this summer. |
Posted By: Andrew McBride
Date Posted: June-12-2005 at 2:58pm
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I appreciate the reply's. I recently found a 86 Ford 351 block with heads so I believe I am on the right track. My fathers friend is helping me do the engine work. I am having the engine reworked by another guy also. I have a couple options. I found a 351 marine block with heads ready to go for 1,385.00 down in texas. all I have to do is bolt up the oil pan and my accessories and it is ready to go.
I am figuring the engine is gonna run me around 1,000 to rebuild it with the new block and heads so I might just buy the 1,385.00 block and go to the lake. I am trying to do it right, but on a college budget! Nothing about these toys is cheap thats for sure. I will post the pics of the boat early this week of the paintwork we are finishing up. Should turn out nice. Engine is my next step and eventually a custom built tower. ------------- Andrew McBride 83' Ski Nautique "Under Construction" |
Posted By: GottaSki
Date Posted: June-12-2005 at 5:53pm
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Beware, just because that engine in Texas is marine, doesn't mean its the correct rotation for you. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: Bob's2001
Date Posted: June-12-2005 at 11:55pm
You have to specify which rotation you want when you order the engine. The one my friend got was reverse rotation. It's been installed for a couple of years and he says he would recommend Thunderbolt to anyone who asks. ------------- Bob Ed 83 2001 |
GottaSki wrote:Posted By: 64 Skier
Date Posted: June-13-2005 at 5:45am
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Marine applications should not be your first rebuild. Buy an old F150 to tow your boat and rebuild/learn on that one. Like cshire said, just bring it to a competent machine shop that assembles engines for a living...the marine application is only a small step for those guy's. I worked with a pretty small Speed Shop and was surprised to hear that they average one marine reverse rotation bore/rebuild per year and knew all the ins and outs.
Shipping engines back and forth costs more than assembling one and must also be a factor in the decision. Good Luck, ------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |