[kg541]

I just purchased a 1998 Air Nautique and I was hoping to get some help on sourcing an engine block for a GT40 5.8L, I believe it's a 351 Windsor. It starts perfectly and was used ony a few days ago for 4 hours. He pulled the spark plug out to find water in the cylinder.

I purchased the boat from a mate who was over spending money on it trying to fix it. One of the cylinders keeps getting water in it. The boat is going to a mechanic this week to be diagnosed but from what he has told me that he seen scoring in the cylinder it seems likley that water is entering the cylinder from the water jackets in the block.

He has had the engine apart twice and has swapped the heads over to find that the water is still entering the same cylinder so I'm hoping the heads will be ok. He also replaced the risers ony 2 months ago on the second strip down. The engine hours are unknown as the hour metre only reads 700 and seems the gauge has been replaced.

Does anybody have some advice on locating a block for this engine. I am extremely excited to get it back in the water. I will get some photos up tomorrow.

Thanks
Kris

[jimmyz]

Hi mate. Try engine master they are in Albury

[lewy71]

Have the exhaust manifolds been changed or only the risers?

[kg541]

Thanks for the response regarding engine master.Both the manifolds and risers were replaced with genuine PCM parts.

We pulled the drivers side head of yesterday and found that the two cylinders towards the back of the boat had water in them. Both cylinders and heads seem fine from a visual inspection.

I have just dropped the head off into the shop to get it crack tested cleaned up and machined. Should have an answer by tomorrow if anything is wrong with it.

[82Juddcraft]

Have u done a leak down test when it was together?
Has it got a standard cam shaft?

[lewy71]

http://www.ebay.com.au/itm/Ford-5-8-351 ... Sw3mpXNR~7

[82Juddcraft]

http://www.ebay.com.au/itm/Ford-5-8-351 ... Sw3mpXNR~7

That's pretty good value.
Block by itselfs usually $1000.
Looks like the bottom ends done, kg could rebuild the rest at home.

[kg541]

Did not perform a leak down test. Wish we had but.
Not sure about the cam, would expect so. We only pulled the head off.

That block looks like a good candidate if the head comes back ok.

I appreciate all the help guys

[kg541]

So I got an interesting call from the machine sop this morning. The head has a crack in it which leads me to thinking that the head was never swapped over at all. Apparently is near one of the valves bot not sure what one. My mechanic is picking up this afternoon.

So now in in the market for a new head. Not sure weather to get a new one or second hand one. I know skidim sell them new for $1600 US but it seems a little high.

Is there a difference between the GT40 and GT40 P. I found these;

http://www.gumtree.com.au/s-ad/heidelbe ... 1135039899

I rung all head (http://www.allhead.com.au) and they can send me a set of recoded ones for $1100 + delivery but I have to give them my old ones. He mentioned that I will likely need my parts to put on the reco heads anyway so better of finding a old set.

Any help would be appreciated.

Thanks

Kris

[82Juddcraft]

So I got an interesting call from the machine sop this morning. The head has a crack in it which leads me to thinking that the head was never swapped over at all. Apparently is near one of the valves bot not sure what one. My mechanic is picking up this afternoon.

So now in in the market for a new head. Not sure weather to get a new one or second hand one. I know skidim sell them new for $1600 US but it seems a little high.

Is there a difference between the GT40 and GT40 P. I found these;

http://www.gumtree.com.au/s-ad/heidelbe ... 1135039899

I rung all head (http://www.allhead.com.au) and they can send me a set of recoded ones for $1100 + delivery but I have to give them my old ones. He mentioned that I will likely need my parts to put on the reco heads anyway so better of finding a old set.

Any help would be appreciated.

Thanks

Kris

I think that P is just the series or cast of head, like Z is the top of the range alloy head.

My first call for all that type of stuff is http://www.eagleautoparts.com.au/index.html
Even if it's not listed on there site they may have it on the shelf.
Ya probably could find some new ones for $800, then all the valve seats will be faced and the deck will be straight.
With second handys you'd wanna get them checked and the seats done.

[lewy71]

The standard heads are refered to as Gt40 heads and have 3 bars cast into the front of head. They are known to crack externally in the water jackets above the exhaust manifolds. The best replacement is the Gt40P heads they actually flow better and have better spark plug placement in combustion chamber. They can be identified by 4 bars on the front of head and GT40P under the rocker cover. They were used in the 5.0L Ford Windsor V8 in Australia up to and including AU model and the imported V8 Ford Explorer.

You will have to drill out the head bolt holes to 1/2" as the 302 (5.0L) only uses 7/16" bolts.

[lewy71]

I purchased a set of reco'd GT40P heads a few years ago for $1200.

[kg541]

Hi Mark thanks for the reply. I am a little stuck what the beast way to go is.

I was concerned about the angle of the spark plugs on the GT40P heads with them fouling with the exhaust manifold but obviously this is not a concern.

Do you know if there is any difference in the GT40 and GT40P heads for marine use. Can I simply purchase a set out of a car and get them reconditioned or do I have to use my lifters ect.

Thanks

Kris

[lewy71]

The spark plug placement is not a problem with the PCM marine exhaust manifolds. It is a concern in cars with headers. The only difference between marine and auto heads is the brass welch (freeze) plugs. You would use your lifters and pushrods and rockers. You will need to check your valve lash with the new head anyway. I good cheap performance upgrade is 1.7:1 rocker arms which gives you a bit more lift. Make sure you number the pushrods and lifters so they go back on the same cam lobe.

[kg541]

Thanks for that. I ended up picking up a pair of GT40 heads from Queensland for a reasonable price. I will have the engineering shop machine them and use my parts on them.

Is there any reason to ensure the existing pushrods and lifters should be placed in the same cam lobes. Person is the the engineering shop has pulled them appear already pulled the old head apart and I defiantly didn't mark the old push rods.

Hopefully will be back on the water for Australia day weekend.

Thanks

Kris

[82Juddcraft]

Thanks for that. I ended up picking up a pair of GT40 heads from Queensland for a reasonable price. I will have the engineering shop machine them and use my parts on them.

Is there any reason to ensure the existing pushrods and lifters should be placed in the same cam lobes. Person is the the engineering shop has pulled them appear already pulled the old head apart and I defiantly didn't mark the old push rods.

Hopefully will be back on the water for Australia day weekend.

Thanks

Kris

Lifts are important. I didn't think the rods matter so much.

[kg541]

Some photos

[fluffy]

Good to hear you got some sorted, 2nd hand by the sounds?
Pushrod placement isn't important, so don't stress. Just roll them along a flat bench to check they are straight ( they wobble if bent)

[JBWake]

Nice looking boat. They are a great all rounder in my opinion.

Back in to it for Aus day weekend would be good timing!

[lewy71]

Rockers and pushrods do not matter that much but definitely the lifters on the cam lobe. Chris you have almost the twin of my 98 Sport.

They are a great all round boat with plenty of storage.