Mercruiser Thunderbolt V 4.3 Parts - Help needed

BIG-SLICK-POKER

I cannot get the serial number off the boat as it does i seem to be there so i cannot determine the year of the boat .

Help required . We figured out the problem after stripping the engine which had ceased due to a crack in the exhaudt manifold which took in water into the heads and cylinders... But after 2 weeks of hard grind we have now freed it up and they heads are gone to be skimmed and valves checked and pressure tested ..

But now i need to put this back together

Looking for the correct exhaust mainfolds to order ,, Any ideas as they seem different from 2003 and mine look alot older as i dont fancy welding the hole as i cannot detrmine the internal state of it .. And if i change one i may as well change both ..

Any good site to find a used thunderbolt v 4.3 or cheaper parts

Neill

fergal.b

Hi Neill there should be a serial number on the engine just above the starter or on the flame arrestor cover, if you can't find one post a photo of your manifold, some are wet and some are dry if its dry it will have a hose going from the bottom of the manifold to the top of the riser.

Hifive

Looking for the correct exhaust mainfolds to order ,, Any ideas as they seem different from 2003 and mine look alot older as i dont fancy welding the hole as i cannot detrmine the internal state of it .. And if i change one i may as well change both

Hi Neill,
Mercruiser changed to a "dry " manifold in 02/03 so it's likely that you need the older "wet" design.
Welding isn't going to work as if it's holed, it's likely buggered inside anyway.
Definitely change both sides. These only have a life expectancy (in salt water) of 5 to 7 years in a raw water cooled motor and as you've found out, failure can lead to big problems.

Trouble is, these things are not cheap @ a couple of hundred sheets a side:eek:
I need a set, plus risers, for a Merc V8 project but I'm struggling to convince herself we need them more than school uniforms/books for the kids:D

Any good site to find a used thunderbolt v 4.3 or cheaper parts

MPD in Swords are as good as any for Mercruiser parts.

http://www.marineparts.ie/engine-parts/mercruiser/exhaust-system/exhaust-manifolds/exhaust-manifold-gm-4-3l-2-pce-type-83-05.html


Regards,
Mark.

fergal.b

I got mine from marine parts as they were the best price around, that night my car got nicked with the manifolds in it, a few days later I got a call from a farmer outside Swords saying he found them in his field along with a receipt with my name and number on it, of the things that were robbed out of the car these were worth the most lucky in some ways I guess.
Try and stay away from secondhand ones if you can they might end up costing you another engine rebuild.

Hifive

fergal.b wrote: »

I got mine from marine parts as they were the best price around, that night my car got nicked with the manifolds in it, a few days later I got a call from a farmer outside Swords saying he found them in his field along with a receipt with my name and number on it, of the things that were robbed out of the car these were worth the most lucky in some ways I guess.
Try and stay away from secondhand ones if you can they might end up costing you another engine rebuild.

I remember hearing about your car being stolen on the other channel. Didn't realise there was valuable boaty stuff onboard!
You were steeped to get the stuff back as without the receipt the insurance co. could well have dug in!
Wasn't that car recovered thrashed?
Also remember it was a unique car which would have been obvious to the scrotes who pinched it (bastards)

A mate of mine got stainless manifolds for a 4.3 from some crowd in the U.K.
They look the business but I think they were serious dosh.

fergal.b

I priced the stainless ones for mine as they are a lower profile and I wouldn't have to make the hatch so tall but at €1000's each I will put up with the hump of the hatch

ps. I just found out a few weeks ago they got the guys that nicked the car from fingerprints, fair play to the Garda for keeping up the hunt.