383 Stroker swap into a 201 Liberator

[Franzel311]

Hello every one my name is Frank and I am new here actually signed up an hr ago but iv been reading the posts made here on various topics since April trying to trouble shoot and look for advise on a project I was finishing up and I'd just like to start off by saying THANK YOU. To everyone on this forum (ppl like Bondo, Tailgunner, Joewithaboat,John S)and everyone else that posts , you have been so help full in all your advise to everyone including my self So here's what I have going on that I could use some sound advise on I put a chevy 350 Mag in my 201Liberator back in the spring and I want more out of it so iv decided to opt for a 383 crate I'd like to build the engine my self but if work keeps up the way it is I won't have the time so iv been talking to a engine builder and this is what he has come up with for me...I am a good marine mechanic but I don't know much more than the day to day regularities of what one would do in a marina, I could build you a champion ship winning jet ski motor iv done it and won it but as for big engines never learned it so if you could take a look at what the guy sent me and give me some advice I would greatly appreciate it

 

[Scott Danforth]

Welcome aboard. there are plenty of posts on building a 383. make sure to use the proper pistons for the proper quench. the pistons should match your combustion chamber.

will you be running vortec heads?

which drive are you running? while you can put a 383 in front of an alpha drive, and they can be made to last, they are not recommended for anything above 300hp.

 

[Bondo]

Hello every one my name is Frank and I am new here actually signed up an hr ago but iv been reading the posts made here on various topics since April trying to trouble shoot and look for advise on a project I was finishing up and I'd just like to start off by saying THANK YOU. To everyone on this forum (ppl like Bondo, Tailgunner, Joewithaboat,John S)and everyone else that posts , you have been so help full in all your advise to everyone including my self So here's what I have going on that I could use some sound advise on I put a chevy 350 Mag in my 201Liberator back in the spring and I want more out of it so iv decided to opt for a 383 crate I'd like to build the engine my self but if work keeps up the way it is I won't have the time so iv been talking to a engine builder and this is what he has come up with for me...I am a good marine mechanic but I don't know much more than the day to day regularities of what one would do in a marina, I could build you a champion ship winning jet ski motor iv done it and won it but as for big engines never learned it so if you could take a look at what the guy sent me and give me some advice I would greatly appreciate it

Ayuh,..... Welcome Aboard Frank,...... Contact yer local GM Dealer, 'n ask 'bout the GM HT-383,.....

Drop a carb, 'n yer accessories on it 'n Go,.... Brand New Power,....
It's 'bout as close to a Perfect Vortec ya can get, unless ya build it yerself,.....

What Drive ya got on the Lib,..??

 

[Franzel311]

Option 1: · 383 · 410 HP / 5200 RPM · 8.6 compression · Cast heads · High lift cam (505, duration 218-224) · Powdered Metal Rods PMR · Long block with tin · You put your intake manifold on it · Use your carburetor · Can be 2 or 4 bolt main, let us know · Price is: $2550 ( $2200 plus core charge of $350) Option 2: · 383 · 9.5 Compression · 450 HP / 5400 RPM, about 430HP to 440HP @ 5000 RPM · Aluminum performance heads (Power Pro) – 200 runners, 64cc chamber · Cam (560 Lift, duration 224-230) · HB Rods · Long block with tin · Forged Pistons · RPM Performer manifold on it · Use your carburetor · Will be 4 bolt main · Price is: $3450 ( $3100 plus core charge of $350) Thanks for your questions! For option 2, we are using a cast steel crank from Eagle. This is a high quality performance component, and better than cast iron, but if you wanted to move to a forged steel crank it would be $350 additional cost. We do a plateau hone finish and use Molly rings. It is a 1 piece seal. The torque should be about 425-450 at 3200 RPM. It is a roller engine. The through the drive exhaust should be fine. Not sure what the Captain’s Call is, but if you mean the exhaust, it should be fine. We are using a roller camshaft and standard rockers, but if you wanted to move to roller rockers it would be only $150 additional cost. My opinion, and it’s only an opinion, you should go for the roller rockers since you are already going get an additional $100 off when you join us on Facebook, and then whatever you feel better with for the crank. And we will Dyno the engine and give you a Dyno sheet with the results, printed and I can email it to you. This engine will be very reliable and should have a life span the same as option 1. We are using really good heads, and building a high horse power engine which means we’re using higher quality components throughout. So, longevity won’t be impacted. The engine should idle around 1000 RPM give or take, and should be just north of normal, yet smooth. So, being a high performance engine with a high lift cam, it may be expected to idle slightly rougher than a regular engine, yet not overly so. It will run nice.

 

[Franzel311]

I'm planning on going with option 2 with the forged crank and roller rocker up grade unless advised otherwise....the boats a 1990 201Lib with the big daddy king cobra cone clutch drive I'm not sure to the gear ratio cuz the serial/model plack is missing

 

[Franzel311]

And thanks for posting so quickly

 

[Scott Danforth]

If your drive breaks, you cant get parts for it.

aluminum heads on a boat are ok if you have closed cooling, or in certain fresh water locations. some of the more brackish fresh water, not so much, and definitely not in salt without a heat exchanger.

same goes with aluminum intake unless you get a marine specific intake with the bronze water passages

if you run in brackish water or salt and you do not have a heat exchanger, you will need one.

Also, you should be able to get the motor to idle at 850. drives dont like high RPM idles for shifting reasons. I would recommend the roller cam, and make sure they are spec'n a marine cam. The specs look off

I would expect something more around 270 degrees duration. if the cam duration indicated is at 0.050" lift, then you will have about 270 with option 1 anything greater than 270 degree and you run into reversion issues.

Here is the cam I would use myself with thru-drive exhaust http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=202&sb=2

I would look to keep the motor in the 9:1 to 9.5:1 compression range with proper quench

my concern is the questions on the exhaust that you post. I believe you are simply passing along the info from your local builder and he doesnt appear to fully understand marine exhaust and reversion.

 

[Bondo]

Option 1: · 383 · 410 HP / 5200 RPM · 8.6 compression · Cast heads · High lift cam (505, duration 218-224) · Powdered Metal Rods PMR · Long block with tin · You put your intake manifold on it · Use your carburetor · Can be 2 or 4 bolt main, let us know · Price is: $2550 ( $2200 plus core charge of $350) Option 2: · 383 · 9.5 Compression · 450 HP / 5400 RPM, about 430HP to 440HP @ 5000 RPM · Aluminum performance heads (Power Pro) – 200 runners, 64cc chamber · Cam (560 Lift, duration 224-230) · HB Rods · Long block with tin · Forged Pistons · RPM Performer manifold on it · Use your carburetor · Will be 4 bolt main · Price is: $3450 ( $3100 plus core charge of $350) Thanks for your questions! For option 2, we are using a cast steel crank from Eagle. This is a high quality performance component, and better than cast iron, but if you wanted to move to a forged steel crank it would be $350 additional cost. We do a plateau hone finish and use Molly rings. It is a 1 piece seal. The torque should be about 425-450 at 3200 RPM. It is a roller engine. The through the drive exhaust should be fine. Not sure what the Captain’s Call is, but if you mean the exhaust, it should be fine. We are using a roller camshaft and standard rockers, but if you wanted to move to roller rockers it would be only $150 additional cost. My opinion, and it’s only an opinion, you should go for the roller rockers since you are already going get an additional $100 off when you join us on Facebook, and then whatever you feel better with for the crank. And we will Dyno the engine and give you a Dyno sheet with the results, printed and I can email it to you. This engine will be very reliable and should have a life span the same as option 1. We are using really good heads, and building a high horse power engine which means we’re using higher quality components throughout. So, longevity won’t be impacted. The engine should idle around 1000 RPM give or take, and should be just north of normal, yet smooth. So, being a high performance engine with a high lift cam, it may be expected to idle slightly rougher than a regular engine, yet not overly so. It will run nice.

Ayuh,.... Both of those motors would be Great in a Hot Rod, Neither are reasonable Boat motors,....

Waayyy to much Cam,.....
Ya need Power, from Idle(650/700rpms) to 5000 rpms,....

With a loopy idle at 1000 rpms, yer Drive will die a quick death,...

 

[Franzel311]

Ahhh good morning Mr. Danforth I was hoping some one was going to pick up on the builders exhaust ? And read into the post good that's y I just did a cut n past of the email he sent..he's actually not a local builder to me at all I'm in New York and he's in Washington..I started dealing with some one so far away from me because I read good things about his builds here and his numbers were where I kind of needed them to be.Iv read a lot of the 383 build threads and do not recall seeing those specs for a cam so that 1 of the reasons I started this thread.....I was under the impression that the cone clutch cobra was bullet proof and one would realy have to try hard to hurt it am I wrong in thinking that?.....as for the salt water vs. aluminum parts I boat upwards of 95/98percent in fresh water lakes very rarely do I go out in salt unless I go to Fl. for vaca or a special trip somewhere would you still say I would need a heat exchange for that minimum of salt contact if it's flushed well afterwards...I am going to get some kind of after market exhaust system but still want to utilize the diverters and through the prop to keep it a sleeper and not have everyone at the marina thro rocks at me when I go out early in the am

 

[Franzel311]

Ayuh,.... Both of those motors would be Great in a Hot Rod, Neither are reasonable Boat motors,.... Waayyy to much Cam,..... Ya need Power, from Idle(650/700rpms) to 5000 rpms,.... With a loopy idle at 1000 rpms, yer Drive will die a quick death,...

Yea that's what I was thinking but is it just the cam that needs adjusting or the hole package?

 

[Franzel311]

If I tone down to that cam Scott suggests do you guys think that it's could be a good screamer yet hold at 3,000/3,500 all day long as it is the family boat to and we like to do long 100 mile cruises up the river

 

[Scott Danforth]

I personally would find someone else to build the motor. someone like Michigan Motorz or Rapido Marine since they live and breath marine motors. or just buy the HT-383.

Rapido has 383 long block motors for $3200 on their web site.

If you want to build it yourself, read this:
http://www.marineengine.com/boat-forum/showthread.php?405563-Turning-a-350-into-a-383-stroker
http://www.marineengine.com/boat-forum/attachment.php?attachmentid=6074&d=1356105816

 

[Scott Danforth]

http://www.m a r i n e e n g i n e.com/boat-forum/showthread.php?405563-Turning-a-350-into-a-383-stroker

remove the spaces

 

[Franzel311]

Iv read good things about both those places you just listed..I will talk to each of them...have you ever heard of Motor Works outa Wa. Iv seen there name on acouple forums here?

 

[HT32BSX115]

.............................not a local builder to me at all I'm in New York and he's in Washington........................................ .....I was under the impression that the cone clutch cobra was bullet proof and one would realy have to try hard to hurt it am I wrong in thinking that?

.............................................as for the salt water vs. aluminum parts I boat upwards of 95/98percent in fresh water lakes very rarely do I go out in salt unless I go to Fl. for vaca or a special trip somewhere would you still say I would need a heat exchange for that minimum of salt contact if it's flushed well afterwards........................................ ....

I am going to get some kind of after market exhaust system but still want to utilize the diverters and through the prop to keep it a sleeper

Howdy,

I have one of those Liberators that I pulled a King Cobra engine and drive out of and replaced with a Mercruiser...........

Sounds like you're talking to US engines in Kent, Wa........... They tend to make claims like you're getting on the engine. (although they're supposed to know the difference between a marine engine and a NON-marine (cammed) engine.

The Cone Clutch Cobra, while it was a fairly well designed drive, they only made them for a few years, the company no longer exists and many parts are NLA.

Couple a 1000 RPM IDLE with that drive and you risk breaking parts you can no longer buy.........In addition, couple a huge amount of HP to the same drive and watch what breaks then. "Roll the dice"

Exhaust is your choice........You're going to have fun finding the Y-pipe for that engine and drive if you don't already have it. Regardless of the exhaust you use, you'll have reversion if you do not use a marine cam.

I would suggest you get an engine from someone local. That way if you have any problems with it you won't have shipping and thousands of miles of distance to deal with!

If you want to make that Liberator "fly" find a Mercruiser Bravo I (or Volvo SX) drive. This way you'll have an engine and drive that is supportable when something breaks.........

I suggest you part out the OMC drive, gimbal and engine accessories. There's still a fair amount of people out there that have broken their OMC "stuff" and are agonizing over looking for replacements. (I sold my 460 King Kobra drive for $1450 and sold all the other "stuff" over a 3 year period for a total of $3500........and I still have 2 SS props that I'll still probably get rid of eventually!)

Good luck,


Rick

Oh, also, I wouldn't put any performance engine in any boat without also adding closed cooling. I added it to my 454 Mercruiser Bravo and everything about it runs better! I don't worry at all about salt water or winterizing!

 

[Bondo]

Yea that's what I was thinking but is it just the cam that needs adjusting or the hole package?

Donno,.... No mention of which heads, the higher compression motor might be a candidate for a different cam, but Alotta factors figure in,...

With Vortec heads, 'n pistons that mirror 'em, No doubt potential there,...
Hi-9s, but under 10, with a .043/ .045" quench,....

 

[Franzel311]

Hey HT32 what kind of boat did you put that 454 in and size I have two complete running and seriously worked 454's I took out of a 31' stinger the first plan was to repower the 201 with one of them but then was talked out of it because of weight VS. power

 

[Franzel311]

HT32 what sized Lib did you put that BB in I have two worked Merc 454 I took outa a stinger with like no hrs so that was the first plan to use one of them to repower the boat wit but was talked out of it

 

[Franzel311]

Sorry about that I keep getting kicked off the site then it doesn't show the posted msg then it pops up outa nowhere... I don't know if it's my comp or what

 

[Franzel311]

Aluminum performance heads (Power Pro) 200 runners, 64cc chamber ...what other info should I ask for?