Replace blown GT40 advice.
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=26931
Printed Date: May-15-2024 at 12:20am
Topic: Replace blown GT40 advice.
Posted By: 2001SAN
Subject: Replace blown GT40 advice.
Date Posted: July-11-2012 at 1:58pm
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Hello all, I have a bit of a dilemma. My GT40 (2001 Super air) had a cracked block when I bought it. The boat has been in the shop since May. My heads and intake checked out ok so i only needed a short block, however, a long block was all that was available. I had planned to replace the standard heads on the long block with the GT40 heads from the old engine. The mechanic is happy enough to do so but I 've just had a fairly lengthy chat with him and he says that if it was his boat he'd put the new long block in complete and leave the old GT40 heads off. He reckons that the power difference would be negligable considering the heads are older (500ish hrs and have had milkshake oil aroung them) and the GT40 fuel injection system will be going back on. He said that the old heads would have wear on the valves etc and he doesn't see the sense in it. He says it's up to me though! I'm confused. What do you guys reckon?? Advice please! D. 
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Replies:
Posted By: TRBenj
Date Posted: July-11-2012 at 2:05pm
Well, of course you will want to do a valve job on the heads before putting them back on... any mechanic that suggests otherwise wouldnt be working on an engine of mine!  But yes, you will notice a significant difference in power if you lose the GT40 heads. That was the primary difference between the standard 351w (240-255hp) and the HO version (285-310hp). ------------- |
Posted By: 2001SAN
Date Posted: July-11-2012 at 3:43pm
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How long/how much for the valve job? I'm scared that this boat is not going to be back on the water this season at this rate! Getting depressed... D. 
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Posted By: TRBenj
Date Posted: July-11-2012 at 3:45pm
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That would be a question for your engine builder. Meaning your new engine builder, not the guy currently working on your boat! A valve job should only take a few days. ------------- |
Posted By: 2001SAN
Date Posted: July-11-2012 at 4:46pm
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i guess thats not too bad. are replacement parts likely to be generic between various heads or will i be waiting for stuff to be ordered specifically for a GT40 head - remember i'm in ireland and all these 351 ford parts are scarce at best. forgive my ignorance! D. |
Posted By: hotboat
Date Posted: July-11-2012 at 5:00pm
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Wouldn't hurt to put the new motor in n run, heads are easily swapped with engine in boat at a later time ------------- Brian |
Posted By: TRBenj
Date Posted: July-11-2012 at 5:28pm
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I dont think Id be too excited about doing a head replacement in a v-drive if it could be easily avoided. Shops that service heads around here have all the stuff they need right on the shelves- its pretty generic stuff. I have no idea if the case is the same in Ireland or not... but Id be surprised if the seals, etc were considered to be super special. Id be searching out a competent shop ASAP. I would not look to your current mechanic for a recommendation! ------------- |
Posted By: 2001SAN
Date Posted: July-11-2012 at 5:52pm
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The mechanic is one of two guys around here and everyone I've spoke to says he's the best. He's no backyard guy, big business with big contracts with large ferry operators etc. Pressure testing the heads etc was done by a machine shop near by. If I do go for the valve job I doubt it'll be him doing it. He outsources that sort of fiddly stuff it seems You reckon the head swap on a v-drive would be a PITA? How many hrs would you be talking? Boat fever is killing me... |
Posted By: uk1979
Date Posted: July-11-2012 at 6:05pm
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Darren, take a look at these guys over here,you could pop over and pick a lump up. +1 with Tim I doubt your head are shot just a mess from poor winterising a picture would help..? Look at part1 in the ford section http://www.realsteel.co.uk/" rel="nofollow - 351w as you can see they build too but it is race season but with all this rain they may have time on there hands give them a call  Oh and give the site some time to load its a bit slow on my PC. Good luck Roger. ------------- Lets have a go 56 Starflite 77 SN 78 SN 80 BFN |
Posted By: TRBenj
Date Posted: July-11-2012 at 6:07pm
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Ive never had to work on a v-drive, but maneuvering exhaust manifolds and heads into and out of that hatch does not seem appealing in the least. Each piece weights ~50 lbs. I also dont like doing work twice, especially if I know that it could be done once and then forgotten about. But thats just me. Maybe you wouldnt miss the extra 50hp? I would. ------------- |
Posted By: 2001SAN
Date Posted: July-11-2012 at 8:10pm
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thanks for the link. Those guys didn't come up in my weeks of searching! However, the long block is bought already. The heads are ok, just had them pressure tested to make sure they were not cracked. I'll see about the heads having the valve job. If it only takes a few days then i'll go for that. Failing that i'll drop in the standard for the time being and see about the swap over the off season. The hatch is the full beam of the boat when you take all the dividers and ballast tanks out and access is not as bad as you'd think. I do agree about doing, and paying for, something once and all that but i'm dying to get in the water asap. |
Posted By: mull282
Date Posted: August-22-2012 at 12:23pm
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Not the only irish owner with a cracked block Darren. Not long off the phone with my mechanic who I'd got to look at my 88 2001 after it had been in my garage for the last 2 years (young kids). Both manifolds cracked and believes the block is cracked as well. Starts on the button but milky oil after a couple of minutes running My own fault. Garage wasnt heated (apart from well insulated boiler) and I only had a blanked surrounding the engine with the cover down) Not happy...now to see what my options are |