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Merc 420 Cyclone engines
- Thread starter BDC1013
- Start date
old377guy
Charter Member
MILD THUNDER
New member
I agree.
BDC1013
New member
alright sounds good. Get in touch with the guy and find out if he still has the engine if you can, that would be greatly appriciated. Ill find more out about the engine i have once i am able to get it out of the boat.
MOBILEMERCMAN
Founding Member / Competitor
Stay away from that and most any craigs list Florida engines. This particular one could be a 330 or a 365 by the picture. Neither is a match to what you have. Nothing will match except maybe the flame arrestor and distributor.
It would NOT be worth the freight to you if it were free.
MOBILEMERCMAN
Founding Member / Competitor
That is worth looking in to.
MOBILEMERCMAN
Founding Member / Competitor
First thing is to pull plugs check for rust. Spray oil in cylinders and see if it can be turned by hand.
You could prime the oil, crank it and pray it will be OK. All it needs is a pit mark or rust on any one of a number of critical surfaces and that part will fail in a few hours or less. It really needs to come apart and shown some love. Remember it sat for 15 years. The odds of it being fine are slim IMO.
You could prime the oil, crank it and pray it will be OK. All it needs is a pit mark or rust on any one of a number of critical surfaces and that part will fail in a few hours or less. It really needs to come apart and shown some love. Remember it sat for 15 years. The odds of it being fine are slim IMO.
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MILD THUNDER
New member
I agree with Jim. The engine that is in the boat, is probably useable, but only after a teardown and mild freshening. I wouldnt just attempt to fire it and run it. It shouldnt cost that much to open it up, inspect Everything, and go from there. I'd definitly wanna do valvesprings/seals before anything.
Ratickle
Founding Member / Super Moderator
??????
A 420 Mercruiser, 454CuIn, engine.
With today's advancements in cam's (reasonably priced modification if you have to change springs anyway), porting knowledge of heads and intakes, (I believe they were 8.8 to 1 comp ratio). Are there any other cheap changes to improve the engine? And what would you expect the final horsepower to be, and at what RPM, when done?
I'm thinking instead of 420, you may be as high as 475 at 5400RPM with just those couple of small changes.
A 420 Mercruiser, 454CuIn, engine.
With today's advancements in cam's (reasonably priced modification if you have to change springs anyway), porting knowledge of heads and intakes, (I believe they were 8.8 to 1 comp ratio). Are there any other cheap changes to improve the engine? And what would you expect the final horsepower to be, and at what RPM, when done?
I'm thinking instead of 420, you may be as high as 475 at 5400RPM with just those couple of small changes.
MOBILEMERCMAN
Founding Member / Competitor
It wasn't hard years ago to do some chamber work, shroud the block and change the cam to find over 500 horses.
Back on topic. The reason why you don't won't to run it after it sat so long is so that you save the good parts replace and/or address whats needed and end up with a good engine. Sure you can make it run the way it sits. It will probably run OK for a few minutes or until you put a load in it. Then when something goes wrong you damage it or destroy it. The end result is you spend more. Its kind of all or nothing to me. Nothing is sell it as is and all is like Mild Thunder states tear it down and give it a freshening .
Different projects would have different objectives:
Do a resto like Thumper and restore it to as it left the factory with the same parts.
Repower it with something new.
Hop up what is there.
Some would like to change it all.
Its the owners decision and Brian has a good idea as to what he wants to do.
Back on topic. The reason why you don't won't to run it after it sat so long is so that you save the good parts replace and/or address whats needed and end up with a good engine. Sure you can make it run the way it sits. It will probably run OK for a few minutes or until you put a load in it. Then when something goes wrong you damage it or destroy it. The end result is you spend more. Its kind of all or nothing to me. Nothing is sell it as is and all is like Mild Thunder states tear it down and give it a freshening .
Different projects would have different objectives:
Do a resto like Thumper and restore it to as it left the factory with the same parts.
Repower it with something new.
Hop up what is there.
Some would like to change it all.
Its the owners decision and Brian has a good idea as to what he wants to do.
Ratickle
Founding Member / Super Moderator
I'm just trying to stay in his $10,000 budget, different options.
R-Freshen-&R, Two #3's - $2000, $2500 with shipping?
R-Freshen-&R, One existing 420 Mercruiser -
Purchase 420 Mercruiser - $2500, $3000 with shipping?
R-Freshen-&R, One purchased 420 Mercruiser -
R-Freshen-&R, Two #3's - $2000, $2500 with shipping?
R-Freshen-&R, One existing 420 Mercruiser -
Purchase 420 Mercruiser - $2500, $3000 with shipping?
R-Freshen-&R, One purchased 420 Mercruiser -
BDC1013
New member
Hey guys, its been a tragic last few weeks on the board over here... I would just like to start off by saying my condolences go out to the family and friends of the loved and lost in the offshore world.
It has been a while since i've done anything with the boat or had any updates, it is coming down to the end of the school semester and I have been just swamped. I received a message about some engines, just thought I'd throw this out there for anyone that may know this gentleman and could give him a good reference.
I have a pair of fresh 420 Mercruiser engines from my Larry Smith Scarab project. These blocks are .030 over, I replaced the crankshafts with new GM forged, they are std/std. They look exactly like yours in the picture. One engine has dyno time and one is yet to be run. I also have Gil exhaust with risers that I would be willing to part out. I would accept your existing engine as partial trade, and provide any exhaust parts that you needed. I would be willing to provide accessories, wiring harness, and whatever parts you needed to make two complete engines ready to install. I have many years rigging experience and am willing to help you with your project. I have purchased two other engines for this project that are higher horsepower. Give me a list of what you think you need, and what you have now. I'll put together a package price that will get you two engines ready to install. I was asking $4,500 each for the engines but have not gotten any serious responses. Depending on the parts you need and what you have we should be able to make a deal that is very reasonable in cost.
Username: Boat1 first name I believe is Bruce.
Thanks guys, I understand what a lot of you are going through right now with the loss. I hope you are all doing well otherwise.
It has been a while since i've done anything with the boat or had any updates, it is coming down to the end of the school semester and I have been just swamped. I received a message about some engines, just thought I'd throw this out there for anyone that may know this gentleman and could give him a good reference.
I have a pair of fresh 420 Mercruiser engines from my Larry Smith Scarab project. These blocks are .030 over, I replaced the crankshafts with new GM forged, they are std/std. They look exactly like yours in the picture. One engine has dyno time and one is yet to be run. I also have Gil exhaust with risers that I would be willing to part out. I would accept your existing engine as partial trade, and provide any exhaust parts that you needed. I would be willing to provide accessories, wiring harness, and whatever parts you needed to make two complete engines ready to install. I have many years rigging experience and am willing to help you with your project. I have purchased two other engines for this project that are higher horsepower. Give me a list of what you think you need, and what you have now. I'll put together a package price that will get you two engines ready to install. I was asking $4,500 each for the engines but have not gotten any serious responses. Depending on the parts you need and what you have we should be able to make a deal that is very reasonable in cost.
Username: Boat1 first name I believe is Bruce.
Thanks guys, I understand what a lot of you are going through right now with the loss. I hope you are all doing well otherwise.
Brian,
If you search OSO you will find I have a negative history from years ago, and if you keep looking you will find I have done what I can to accept responsibilty and make right any bad dealings. I will gladly offer factual information privately that you can check out. I have no interest in defending myself openly on this or any other forum. The engines and parts I have offered are from a personal project and are as described. In light of the location diference I would suggest we use a third party escrow arrangement for funding, if we can agree on a final total price. My experience and capability have never been in question, my business practice and lack of paperwork documentation were a big mistake. I have learned a great deal from my past mistakes and am slowly trying to restore my reputation. I no longer conduct business in my personal name and utilize a limited liability corporation. I do not desire to do business with the general public as I have no employee's. I assist my existing customers/friends with their needs, and work on personal projects. My reputation is very important to me, I will openly discuss any questions pertaining to this specific deal on this forum. Any other discussion should be done privately. Bottom line is I have components that you need to complete your project because I am doing a similar project. I personally did all the engine work on the engines I am offering, and they were intended for my personal use. The starting point was original Mercruiser 420 engines that have been fully rebuilt. The exhaust is used Gill manifolds that are fresh water use to my knowledge and the tails are TRS stainless without the built in mufflers. All wiring harness and accessories are from 1989 TRS application, I offered to provide the starters, alternators, and water pumps in fresh rebuilt condition from an electrical rebuild shop, as I feel this is appropriate for his project. In addition I am willing to accept the old parts he has in trade for price reduction credit. I feel his engine should be inspected before it is run after sitting so long, specifically my concern is the flat tappet camshaft and the lack of lubrication to the lobe surfaces, even with priming the oil system they cannot be lubricated properly to eliminate dry start condition.
If you search OSO you will find I have a negative history from years ago, and if you keep looking you will find I have done what I can to accept responsibilty and make right any bad dealings. I will gladly offer factual information privately that you can check out. I have no interest in defending myself openly on this or any other forum. The engines and parts I have offered are from a personal project and are as described. In light of the location diference I would suggest we use a third party escrow arrangement for funding, if we can agree on a final total price. My experience and capability have never been in question, my business practice and lack of paperwork documentation were a big mistake. I have learned a great deal from my past mistakes and am slowly trying to restore my reputation. I no longer conduct business in my personal name and utilize a limited liability corporation. I do not desire to do business with the general public as I have no employee's. I assist my existing customers/friends with their needs, and work on personal projects. My reputation is very important to me, I will openly discuss any questions pertaining to this specific deal on this forum. Any other discussion should be done privately. Bottom line is I have components that you need to complete your project because I am doing a similar project. I personally did all the engine work on the engines I am offering, and they were intended for my personal use. The starting point was original Mercruiser 420 engines that have been fully rebuilt. The exhaust is used Gill manifolds that are fresh water use to my knowledge and the tails are TRS stainless without the built in mufflers. All wiring harness and accessories are from 1989 TRS application, I offered to provide the starters, alternators, and water pumps in fresh rebuilt condition from an electrical rebuild shop, as I feel this is appropriate for his project. In addition I am willing to accept the old parts he has in trade for price reduction credit. I feel his engine should be inspected before it is run after sitting so long, specifically my concern is the flat tappet camshaft and the lack of lubrication to the lobe surfaces, even with priming the oil system they cannot be lubricated properly to eliminate dry start condition.
