Logo

Need help cruising home on one engine

jclays, the raw water cooled engine plumbing has undergone many changes since the old days. It is actually more efficient now days.
If this was my boat, I would rid myself of that old and odd style plumbing and I would re-configure it into a more modern style.
You would have fewer issues (if any) and it would simplify things for you.
Regarding your post # 29..... No expensive OEM parts...... no hunting for NLA parts....... no machine shop modifications....... and so on!

Do it once, and don't look back!
:D


Just a thought!




.
Good morning
The only thing keeping me from upgrading is the intake manifolds. I haven't seen any of the newer ones that have a profile as low as the old ones on my boat. I currently only have about one inch from the bottom of the closed deck hatch to the top of my flame arrestor. I dont want a raised deck or hump to accommodate a higher rise on the intake manifold.
 
Good morning
The only thing keeping me from upgrading is the intake manifolds. I haven't seen any of the newer ones that have a profile as low as the old ones on my boat. I currently only have about one inch from the bottom of the closed deck hatch to the top of my flame arrestor. I dont want a raised deck or hump to accommodate a higher rise on the intake manifold.

Could the two intake manifold outlet ports be closed off .... followed by installing a later style T-stat housing?
 
attachment.php
You say that the intake has a blank where the thermostat housing would normaly be, sounds like the intake on my engine. except mine is a closed system and has a reservore where you have the housing. interestingly enough, My engine has no thermostat at all and no place to put one. I see on the right side of your engine you have a hose that looks to be 1 inch and goes down under the engine, what is that?

Also I am using a Rochester 4jet carb (1967 vintage) as the intake is a square pattern and the holes are all the same size. Like you I can't put a taller intake on due to height.
 

Attachments

  • DSCF0003.jpg
    DSCF0003.jpg
    73.5 KB · Views: 240
Last edited:
6500-CB.jpg
The lower tstat housing with the bridge to connect to the 2 out flow ports in my intake manifolds. This is the piece that my low profile intake manifolds need. Part is looong gone. I could possibly have a line on 2 used ones I should be getting a call back tomorrow. At what price????. Have some very plausible Ideas to mimic The original part. Wont be pretty but should work.
 
Anyway put everything back together with thermostat even though it is bypassed. It is in the condition that I have been running with since I bought the boat used 12 years ago. Has always run good. Just very cool.
Running at 800 rpm for 40 min to exit harbor 5 knot speed limit inside. Port side engine exhaust manifold left side 165 degrees, right side same engine 155 degrees. Out of the harbor increased rpm to 2100 at 14.5 knots same engines same sides both dropped to 106/108 degrees. Starboard engine stayed at 106 the whole time. Exhaust elbows were running 135 to 155 degrees on both engines.

I ordered new exhaust manifolds and elbows for both engines. Its time. Thats the only place I have not yet eliminated any blockages.
Thanks
Jim
 
Looks like your source in Europe has two locations, one being in the UK....From what i read, it could be their version of the NLA Crusader housing....so it may be worthy of a premium. I would compare it to whatever your costs would be to 'mimic' the original....I wouldn't think it difficult to bore two holes and tap them....clearance would be the only concern...That 'bridge' in the original style appears to connect to the head coolant ports - is the intake 'short' (front to back) to permit this??? or does the intake just provide a 'pass-thru' on the flange and the bridge sit on the intake?
 
Looks like your source in Europe has two locations, one being in the UK....From what i read, it could be their version of the NLA Crusader housing....so it may be worthy of a premium. I would compare it to whatever your costs would be to 'mimic' the original....I wouldn't think it difficult to bore two holes and tap them....clearance would be the only concern...That 'bridge' in the original style appears to connect to the head coolant ports - is the intake 'short' (front to back) to permit this??? or does the intake just provide a 'pass-thru' on the flange and the bridge sit on the intake?

The intake is full size with pass thru on each side at the coolant ports
 
Never seen a standard production cast iron manifold without the coolant passages/tstat 'neck' .....

another option (no machining required) would be to remove the NPT sensor and install a TEE fitting and any adapters required to connect the open ends to the coolant passages coming from the heads....if you can't relocate the temp sender fitting to another existing hose, you could add it to the top of the housing....
 
Never seen a standard production cast iron manifold without the coolant passages/tstat 'neck' .....

another option (no machining required) would be to remove the NPT sensor and install a TEE fitting and any adapters required to connect the open ends to the coolant passages coming from the heads....if you can't relocate the temp sender fitting to another existing hose, you could add it to the top of the housing....
Is it ok to reduce from 1-1/4 inch hose ?
 
I don't think it is optimal but it will be functional....you can always add another NPT hole, for the other hose, to the other side of the housing....either way, i don't see how you can do it without a 'reducer' fitting which will induce another pressure drop....which I don't see as a big issue because its a low pressure system to start with and, once the thermostat opens, there's not much of the system left to traverse....

FWIW, I've seen many mercruiser engines and a few custom ones that use 3/4" ID hose in the same spots Crusader uses the 1.25"ID hose....w/o any issue at all...
 
I will be replacing the manifolds and elbows on both engines this weekend and hopefully all will be good. As I noted on post #36 "Running at 800 rpm for 40 min to exit harbor 5 knot speed limit inside. Port side engine exhaust manifold left side 165 degrees, right side same engine 155 degrees. Out of the harbor increased rpm to 2100 at 14.5 knots same engines same sides both dropped to 106/108 degrees. Starboard engine stayed at 106 the whole time. Exhaust elbows were running 135 to 155 degrees on both engines". Seems like some water flow issues on that Port side engine at the lower RPM range.
 
could be water flow delta...unless you measure the water output, you'll never know....

New manifolds & elbows will resolve a couple potential problems...
 
I have missed what vintage the engines are. I am curious, I have older Crusader 454's as well but mine have oil coolers between the sea water pump and the thermostat. I don't see in his pics. Were these coolers optional components? P.S. my engines run rock steady at 145. Raw water.
 
Jim says they are in a 1966 hull.....I don't have any factory data that far back so can't say about the coolers....I would think they were standard equipment...but he's got the small blocks, so the gear may be the only thing with an oil cooler.
 
Last edited:
I have missed what vintage the engines are. I am curious, I have older Crusader 454's as well but mine have oil coolers between the sea water pump and the thermostat. I don't see in his pics. Were these coolers optional components? P.S. my engines run rock steady at 145. Raw water.

Not sure the history of the engines. They are 350's. Not original to a 1966 boat. Each engine has a trans oil cooler. My engine circulating water pump has an outlet that feeds the cooler. The water then flows thru the cooler and into a fitting in the exhaust elbow. Im sure this is not the original plumbing configuration. But it has worked since before I purchased the boat 12 years ago.
 
water flow delta = difference in water flow, in this case between the two engines....not an easy measurement to make because you usually have to change the path the water takes to make the measurement....

The circulating pump, on the front of the engine , has an inlet that should be fed from the t-stat housing......the raw water pump typically feeds cooling water to the oil cooler and then into the tstat housing to keep the block and the exhaust manifolds wet.
 
Replaced 3 out of the 4 manifolds (both engines) will finish with the fourth this morning. Boy am I sore. Disturbing find yesterday. The infamous Port engine. Upon removing the left manifold ( looking from the rear) I noticed a little bit of water trickling out of the rear exhaust port on the engine. Pulled the coil wire and cranked the motor over a few seconds. Got about 2 table spoons of water out...Hoping not a head gasket.
 
Replaced 3 out of the 4 manifolds (both engines) will finish with the fourth this morning. Boy am I sore. Disturbing find yesterday. The infamous Port engine. Upon removing the left manifold ( looking from the rear) I noticed a little bit of water trickling out of the rear exhaust port on the engine. Pulled the coil wire and cranked the motor over a few seconds. Got about 2 table spoons of water out...Hoping not a head gasket.

A compression test (aka cylinder pressure test) will show you how well, or not well, each cylinder is able to build pressure.
It will not tell you where a low cylinder's failure point is.

A cylinder "leak-down" test will reveal much more!

.
 
maybe it's not that bad.....did you separate the elbow from the manifold before removing the manifold from the head???
maybe it was just the residual water ???
 
all four manifolds are in fired engines up. Port engine right side looking from rear front exhaust port/gasket leaking exhaust and water. Took is apart today cleared the water and replaced the gasket re torqued the four bolts. Started engine. Leak out of the front again. Shouldn't be water leaking correct? Didnt do it before I replaced the manifolds. Brand new. Cracked water jacket in the new manifold? By the way this is the opposite side of the same engine on posts #49 The left side seems to be ok.
 
if the leak is at the head's forward exhaust port, you are correct - shouldn't leak there.....even if the jacket is cracked......are the inlet flanges of the manifold all flat and parallel?? did you torque the bolts down?

Hate to say it but you need to get a truck load of good luck and bring on the next trip....
 
if the leak is at the head's forward exhaust port, you are correct - shouldn't leak there.....even if the jacket is cracked......are the inlet flanges of the manifold all flat and parallel?? did you torque the bolts down?

Hate to say it but you need to get a truck load of good luck and bring on the next trip....

By eye it appears flat. Will be pulling the manifold off and check. Also crank it and let out any water. Torqued with torque wrench to 30lbs. Gasket at the front exhaust port leaked and started dripping water at the bottom of the manifold and bubbling out of the top. Took off the manifold cranked the engine lots of water came out of the exhaust port. Replaced with new gasket. Still did not seal. Same result. Did not do that before with the old manifold. Was all dry when I removed it thats why Im thinking crack in the water jacket is allowing water in. that exhaust port is just behind where the water intake fitting into the manifold is.
 
Just talked to the parts house and I am having a new manifold shipped to me and am sending them the other one back.
 
Back
Top