Gen VI 7.4L Valve tap

[Scott Danforth]

take a large flat file and true-up the surfaces

then take some 150 grit on a board sander (or the bottom of a concrete float) and smooth out the file marks.

got pics of your 68 satellite? I had one in highschool

 

[mr300z87]

Here you go. and a burnout video too https://youtu.be/JuE6n5MBZJ4


I owned her for 27 years it was not used it much in the last 10 since I bought a boat. LOL plus I have a 1988 Nissan 300ZX which is much easier to drive on our crowded NJ streets. She had a 383 4brl, console shift 727 auto trans and 70 Road Runner suspension. A few weeks ago she went a new home. Not just because I thought I needed a engine for the boat, We are looking at the bigger picture, kids are grown, retirement from my state job in the not to distant future. Its time to start downsizing, Still have the Z, a barn full of car and boat parts, lawn equipment and on and on an on. I am sure many of you know what I am talking about. It was like loosing an old friend and I miss it being in my garage, It was just sitting maybe 500 miles in the last 10 years.


The Z in its new home, way more room in there now. The Plymouth took up every inch of the garage..

 

[alldodge]

Here you go. and a burnout video too https://youtu.be/JuE6n5MBZJ4


I owned her for 27 years it was not used it much in the last 10 since I bought a boat. LOL plus I have a 1988 Nissan 300ZX which is much easier to drive on our crowded NJ streets. She had a 383 4brl, console shift 727 auto trans and 70 Road Runner suspension. A few weeks ago she went a new home. Not just because I thought I needed a engine for the boat, We are looking at the bigger picture, kids are grown, retirement from my state job in the not to distant future. Its time to start downsizing, Still have the Z, a barn full of car and boat parts, lawn equipment and on and on an on. I am sure many of you know what I am talking about. It was like loosing an old friend and I miss it being in my garage, It was just sitting maybe 500 miles in the last 10 years.


The Z in its new home, way more room in there now. The Plymouth took up every inch of the garage..

The 68 looks good, I had a 70 road runner with the air grabber hood. Loved the car, but at the time didn't have the money to fix it up. Back in 76 things were much tighter. Thanks for the pic

 

[Lou C]

In the pic of the manifold, on the extreme left side, the third port from the end, that looks like there is some rust in it. This suggests that the manifold/elbow gaskets may have started to seep, maybe not much but its then a good thing you took it apart for a different reason. As Scott said I'd try to really clean up those sealing surfaces and see how good you can get them. Hard to tell in the pics because the gasket material is still there. The cooling passages look pretty good, no real clogging. I'm also in salt water and have changed the exhaust on this engine approx. every 5--7 years.
I am also a lover of Mopars, but never had an original muscle car but I grew up with them, I remember when they were $4500 cars new and when they were 2 years old (like when I was a senior in HS) you could buy one for $2000. I regret never buying one and plan to eventually get a late model Challenger 392 Scat Pack. I drove one last spring and it was sick! With the 8 spd ZF auto it banged off shifts like a pro stock drag car. Might have to sell the boat to make it happen. Also did retirement 3 years ago, I am still working part time so more time for fun stuff, but gotta sell something to make room for a muscle car.

 

[mr300z87]

My friend from HS in 1983 bought a 1970 Roadrunner for $1300, it was a solid car but no motor no trans. That friend and I have not spoken in 10 yrs for reasons only he knows but from what other friends have told me he still has it plus like 4 others. It went through a 4spd conversion then back to an auto. He then went totally crazy and it became this

it now has 1957 stroked 392 Hemi with a 671 super charger sticking through hood making like 650+HP, when we were still speaking I rode in it, it is totally sick and crazy fast. My dream car is a 1968 Plymouth GTX 4spd but reality is a 1988 Nissan Z and 250 Sundancer. I do still have a 06 Ram 1500 so I suppose its still in the MOPAR family.

Back to the regular scheduled program I picked up all the gaskets I needed yesterday and our crazy NJ March weather is supposed to be decent on Saturday so I plan to put it back together and a quick engine run. Will do as Scott suggested to clean up the gasket surfaces. I plan to drain the block again just to be safe as we still could have weather below freezing. Better safe than sorry. Will post results here over the weekend. Have a great day.

 

[mr300z87]

So today I am getting excited about fixing my engine this weekend and new exhaust coming for my other project the Invader V210 engine install that will become a friends boat when done. Well I go out to put out the trash and get the mail where I find a ordinance violation for having 2 boat in my yard.:mad-new::mad-new::mad-new: WTF I live in the middle of now where (yes it does exist in NJ) on almost 2 acres with a barn and a could other small out buildings on a dead end street. Doesn't the town have anything better to do. Nobody is complaining. OH and I have 8 days to comply or up to $1000 a day fine. Just add it to a long list of thing that need to be done. Sorry for the rant, I am still in disbelief. Going to call the town tomorrow to see if I can at least get an extension for a couple weeks until I figure out what I am going to do. Have a great night

 

[mr300z87]

SUCCESS!!!! Today turned out tot be a nice 55 degrees with bright sunshine, out I went and with the help of a boating friend Don we reassemble the engine with my new $45 worth Merc exhaust manifold, riser and elbow gaskets. I cleaned up all the mating surfaces as Scott mentioned with flat file and sand paper, and on went the exhaust. Had the battery charging while doing the install so once complete we hooked up the hose, poured a couple oz of gas in the carb and we had fire with no tapping noise. I am still amazed at how metallic the exhaust leak sounded. Now back to my regular scheduled pre launch maintenance. I must say that I am relieved. Now I might try and find a canvas guy to make the camper top that we always wished we had. Have a great rest of the weekend. Stay safe with this crazy virus thing going on. Mike

 

[Lou C]

great news and that's a help to anyone hearing the same noise, looking for a solution. BTW, I think broken exhaust manifold bolts on modern Chysler Hemis causes a similar noise!

 

[mr300z87]

Yes I concur on this "I think broken exhaust manifold bolts on modern Chrysler Hemis causes a similar noise!" as mine RAM has a slight tick when cold and I know it has at least 1 broken stud on both heads. It is more of tick, the one on my boat was much louder and sound like a valve tap, very metallic. I have also heard the same issue with with the Nissan's VG30 series engine like in my Z. I am just glad i do not need an engine for my boat.

 

[mr300z87]

This past weekend seemed like the first nice days we have had in forever. So with that I mustered up enough energy to change out the exhaust gasket on other other side as a preventative measure. I am so glad I did not only was the manifold gasket nearly disintegrated but as I was cleaning up the matting surfaces I noticed their condition was not to my liking and one section between the riser and elbow was about to fail, it would not have made the season. New exhaust was ordered which will hopefully be here by the end of the week. The plan was a may 16-17 launch hope this does not delay. Headed to west marine today for a bottom and outdrive paint. Got to keep the ball rolling. Stay safe

Mike

 

[Lou C]

Good news. How many seasons did you have on that exhaust? When I had the OMC one piece manifolds that they used on the V6 (similar to what Merc used on their version of the V6) I replaced them every 5-6 seasons here in salt water. While some said they were bad and prone to failure I had 3 sets of them on this engine and never had water in a cyl. With the 2 piece exhaust I’ll see how long I get before I get rust stains at the joint between the manifold and elbow....

 

[mr300z87]

Believe it or not I reused them during my engine replacement as they seemed good at the time. I ran them 3 season in Barnegat Bay (mostly salt) and the Toms RIver (almost fresh) where my slip is. So they don't owe me a thing.

You can see the rust staining on the gasket and also the gasket on the bottom between the water jacket and the exhaust was decayed. When I saw the flange in the corresponding spot on the 3"riser I knew it was time. Parts are coming. In the mean time it bottom and outdrive painting time.

Lou C where do you Boat?

 

[Lou C]

Yep you can see exactly where the gasket started to get compromised. I am on the north shore of Long Island, Suffolk County. So mostly in local bays and on very good days LI Sound. 100% salt water, most of it pretty deep but there are shallow areas with rocks you have to watch out for. Furthest I've ventured out is approx. half way across the sound to Conn. Its pleasant on summer days in the morning but as the air heats up it gets windy so you have to head back in before that especially with a small boat.

 

[mr300z87]

I have lived near the New Jersey shore my entire life and have only been to Long Island Once and I did not even go that far out LOL. Both the BQE and the LIE were so much fun with a manual trans pickup. Long ago I sailed from Conn to Block Island on a 37 ft. I can see the Long Island sound getting rough for smaller boats as does Barnegat Bay.

Just for kick I photoed the riser surface to share In this pic the upper water jacket matches the lower one on the pic in post #52. Although it is bad the photo makes it look way worse. But still not worth risking.



I had planned to post this a last week but the forum was haivng PIC issue.

New Exhaust is on Starboard side. Still have the old exhaust on the port side. Hope to change it before launch next week. It was in way better condition.

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[Scott Danforth]

take a belt sander with 80 grit and true up the surface

then follow up with 120 grit

it looks better than most, however the surface needs to be cleaned up to good metal, you have some surface corrosion.

 

[mr300z87]

Scott its to late all new MerCruiser exhaust installed on starboard side. Port side is still in the garage and the old ones are still on the engine. They were in much better condition, I think I posted pic earlier in the thread. If the weather holds and I get everything done I am splashing this Wednesday and will probably not change out port side until the fall. But if the splash is delayed I might go ahead and change now.

Today I finished bottom paint and she looking almost ready. Tomorrow I will get the drive back on and finish painting it and the transom assembly as well and dozen or so other items on the to do list. I am beat Have a great night.