4.3L Mercruiser upgrades
03-12-2010, 10:29 AM
#21
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I have an 01 crownline 18'
upgraded cam, bowl work on vortec heads, valve springs and pushrods, with stock, edelbrock intake and carb 1" spacer.
with stock ignition setup it made 290 ft lb at 3400 306ft lb at 4500 peak horsepower was at 4900 279 horsepower all numbers are corrected
After 3 prop changes ended up with 24 pitch 4 blade I think it's 13.5" diam when empty if you have 4 passengers pulling tubes or skiing went with a 21 pitch 3 blade 14.25" diam
It seemed like the factory rev limit was a limitation on the water 54mph so I change the igntion over to a fireball ignition box now the rev limiter sits at 6600 it will pull to the limiter with the 21 pitch prop with up to 4 people in the boat.
The boat is a ton of fun!
I almost have myself talked into a procharger but haven't bit the bullet yet.
upgraded cam, bowl work on vortec heads, valve springs and pushrods, with stock, edelbrock intake and carb 1" spacer.
with stock ignition setup it made 290 ft lb at 3400 306ft lb at 4500 peak horsepower was at 4900 279 horsepower all numbers are corrected
After 3 prop changes ended up with 24 pitch 4 blade I think it's 13.5" diam when empty if you have 4 passengers pulling tubes or skiing went with a 21 pitch 3 blade 14.25" diam
It seemed like the factory rev limit was a limitation on the water 54mph so I change the igntion over to a fireball ignition box now the rev limiter sits at 6600 it will pull to the limiter with the 21 pitch prop with up to 4 people in the boat.
The boat is a ton of fun!
I almost have myself talked into a procharger but haven't bit the bullet yet.
03-12-2010, 02:33 PM
#22
Staging Lane
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I have an 01 crownline 18'
upgraded cam, bowl work on vortec heads, valve springs and pushrods, with stock, edelbrock intake and carb 1" spacer.
with stock ignition setup it made 290 ft lb at 3400 306ft lb at 4500 peak horsepower was at 4900 279 horsepower all numbers are corrected
After 3 prop changes ended up with 24 pitch 4 blade I think it's 13.5" diam when empty if you have 4 passengers pulling tubes or skiing went with a 21 pitch 3 blade 14.25" diam
It seemed like the factory rev limit was a limitation on the water 54mph so I change the igntion over to a fireball ignition box now the rev limiter sits at 6600 it will pull to the limiter with the 21 pitch prop with up to 4 people in the boat.
The boat is a ton of fun!
I almost have myself talked into a procharger but haven't bit the bullet yet.
upgraded cam, bowl work on vortec heads, valve springs and pushrods, with stock, edelbrock intake and carb 1" spacer.
with stock ignition setup it made 290 ft lb at 3400 306ft lb at 4500 peak horsepower was at 4900 279 horsepower all numbers are corrected
After 3 prop changes ended up with 24 pitch 4 blade I think it's 13.5" diam when empty if you have 4 passengers pulling tubes or skiing went with a 21 pitch 3 blade 14.25" diam
It seemed like the factory rev limit was a limitation on the water 54mph so I change the igntion over to a fireball ignition box now the rev limiter sits at 6600 it will pull to the limiter with the 21 pitch prop with up to 4 people in the boat.
The boat is a ton of fun!
I almost have myself talked into a procharger but haven't bit the bullet yet.
Thats awsome!
Thanks for the info on props!
03-25-2010, 10:10 PM
#24
Teching In
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I'm in the process of gathering the parts for the same swap, have a line on fresh vortec heads edelbrock intake, 600 carb, and a cam. I asked on iboats haven't got much of an answer but should i leave the stock cam in. It's a 17' starcraft. Specs on the cam I'm lookin at are
intake exhaust
474 483
250 288
w/ 108 lobe seperation
intake exhaust
474 483
250 288
w/ 108 lobe seperation
04-01-2010, 10:02 AM
#25
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I'm in the process of gathering the parts for the same swap, have a line on fresh vortec heads edelbrock intake, 600 carb, and a cam. I asked on iboats haven't got much of an answer but should i leave the stock cam in. It's a 17' starcraft. Specs on the cam I'm lookin at are
intake exhaust
474 483
250 288
w/ 108 lobe seperation
intake exhaust
474 483
250 288
w/ 108 lobe seperation
I would email mercruiser about your cam specs if you have the engine serial# which is usually listed on the arrester cover. That way you can get a good idea on what was in there.
Yea I like Iboats for some things but those die hard marine guys will argue the fact that car parts will work and "marine" parts are better... They are so snotty and full of crap. Definitely run the heads they are so much more of an improvement over the pre vortec heads and the 4 barrel intake should make a big improvement power wise. Then its time to figure out your prop depending on what you do with the boat. I do a little bit of everything fishing, tubing, plus the occasional waking up extra early on the weekend and trying to max out the speedo needle before the lake gets crazy in the afternoon.
heres the info they sent me on my cam, it was out of a 91 Thompson Calae 195.
04-06-2010, 06:50 PM
#26
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I'm going through the motor before I put the heads on and putting new bearings and gaskets in it, is the head gasket the same for vortec and non vortec heads? I have a bearing kit, just don't know what head gasket to run.
04-07-2010, 07:08 PM
#27
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I believe the head gaskets for the vortec heads are different. Marine gaskets have a stainless steel core where the automotive head gaskets do not use a stainless core. I will have to check tomorrow, I could be wrong but I'm pretty sure the gasket is slightly different
I am going to run automotive gaskets.
I am going to run automotive gaskets.
06-17-2010, 01:57 AM
#29
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4.3l v6 marine engine hey i was scanning the net thinking about doing the same thing to my boat changing over to vortec heads and 4bbl carb and intake.were can i find the intake at a good price!! i have a 1988 donzi with the 4.3l 2bbl. i have been a automotive tech. for 20 years amd worked on a few boats over the years and there is really no difference in most of the parts accept for the alternator and a couple other things.but if you know were i can get a good price on the vortec heads and intake and carb let me know please.thanks also the boat forum does suck c_ck!!
07-09-2010, 08:21 AM
#31
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Are you inquiring about the 4.3L Vortec heads that I had the 2.02/1.60 stainless valves and CNC bowl/exhaust port work? They are definitely not for sale
they are just too bad *** to part with LOL
The heads that came off are not actual Vortec heads with the fast burn chambers but if for some reason you wanted them you could have them for $100 + shipping.
You will never believe it but I got my intake at a Marine junkyard for $125.
Hildebrand's Marine and Snowmoblie Salvage Yard
298 South Fremont Road
Coldwater, MI 49036-9426
(517) 238-2828
If they dont have one, check this place out it is the best Marine salvage yard I have ever been to
Checker Marine Service
3280 West Stein Road
La Salle, MI 48145
(734) 243-2683
they are just too bad *** to part with LOLThe heads that came off are not actual Vortec heads with the fast burn chambers but if for some reason you wanted them you could have them for $100 + shipping.
You will never believe it but I got my intake at a Marine junkyard for $125.
Hildebrand's Marine and Snowmoblie Salvage Yard
298 South Fremont Road
Coldwater, MI 49036-9426
(517) 238-2828
If they dont have one, check this place out it is the best Marine salvage yard I have ever been to
Checker Marine Service
3280 West Stein Road
La Salle, MI 48145
(734) 243-2683
07-09-2010, 08:24 AM
#32
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You will probably never believe this either but I got the heads from a kid guy on Craigslist for $30. You just have to make sure you get the hedas from a 96+ 4.3L engine to get the redesigned chambers. They are not identical to the 305/350 Vortec heads because the floor doesn't follow the same curvature but they are much better than the heads that came on the engines 95 and earlier.
