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A little help if you have a minute..

A 253 to run a real 65 mph with a small block....:eyecrazy: That would be one hell of a small block.



"This is not a normal small block, it is a Stroker worked motor with ported heads, roller rockers, lunati forged crank etc. "

You said this engine was assembled by Merccruiser. Not saying I know it all, but I didnt think Merc ever assembled an engine with a Lunati crank and ported heads. If they did, I would think it would cost alot more than what you are paying. Not trying t be critical here, just trying to save you grief. If its a Merc engine, whats the Mercruiser part #?
 
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Whatever route you take, I wouldn't let this shop do the work for you, sounds real fishy. However, I am running a 383 if you have any questions.
 
vinny p. said:
A 253 to run a real 65 mph with a small block....:eyecrazy: That would be one hell of a small block.



"This is not a normal small block, it is a Stroker worked motor with ported heads, roller rockers, lunati forged crank etc. "

You said this engine was assembled by Merccruiser. Not saying I know it all, but I didnt think Merc ever assembled an engine with a Lunati crank and ported heads. If they did, I would think it would cost alot more than what you are paying. Not trying t be critical here, just trying to save you grief. If its a Merc engine, whats the Mercruiser part #?
Click to expand...


Sounds like it may be a summit or Jegs switcharoo.. & pocket the "marine application" difference or put it towards expensive black spray paint..

If you proceede, do so with caution.. Like my mamma said if it sounds too good to be true.. (you know the rest)..

Jamie / Lakeside

.
 
vinny p. said:
A 253 to run a real 65 mph with a small block....:eyecrazy: That would be one hell of a small block.



"This is not a normal small block, it is a Stroker worked motor with ported heads, roller rockers, lunati forged crank etc. "

You said this engine was assembled by Merccruiser. Not saying I know it all, but I didnt think Merc ever assembled an engine with a Lunati crank and ported heads. If they did, I would think it would cost alot more than what you are paying. Not trying t be critical here, just trying to save you grief. If its a Merc engine, whats the Mercruiser part #?
Click to expand...


it probably comes from the performace shop - they do tend to use higher quality components there.
 
from one wannabe to another...
no one has stated what a stroker is and i think you asked earlier.

you take a 350 block, put a 400 crank in it, bore it to a certain overage (ie. .030) and there you have it... 383ci. the larger crank is turned down to match the 350 block bearings. the piston travels further per stroke - thus it is called a stroker.

from what i have heard (around cars) they are great motors but but most are going up from a 350, not down from a 454.

I agree with all the others - big block vs small block is like apples and oranges, both are round but make different pies. they sound different and they push different.

a last consideration if still considering the 383 - gas milage. perhaps one of the pro's can calc if it would go up or down. i would think better milage but how much, would it be worth it. and i would get the it will do 65+ (GPS since most boat spedo's are way off) in writing or your money back (they can have their motor back) - if they are that certain they should be willing to stand behind it. if not buyer beware.

ok-1 more last consideration - would 65 be the wot. if you want to cruise at 65 (say 85% throttle) the engine will last longer because it is not sooo close to its wot limit which is good for shorter runs.
 
Hey cool, just noticed i've been upgraded to a jetmate :banana:

anyway, I checked with my local engine builder and he just shook his head and said no way would he step down like that. he currently has at least 3 bare 454's waiting for anyone who needs an engine built.

to see what kind of work they are capable of here is a marine engine he is working on right now http://www.wallysprecisioninc.com/images/engines/engine8may.jpg this is a inter-cooled blower motor with 2 4bbl carbs. originally planned for 1200 hp. - they work a lot locally but have clients throughout the u.s. and a few internationally. their site is new and they are still adding pictures.

my engine should be ready friday!!! :drool: so i feel your pain and confusion. took me a bit to determine what to do. I will post pics to their site after it is complete.
 
Thanks again for all the pros and cons guys - honestly, I really appreciate it.
All I am looking for is a motor to replace my blown 454. As much as I would like to upgrade to a 496, it's just not in my budget. I spoke to Mercruiser again today and assured this is the new motor to replace the non existent 454 which obviously is no longer in production. It has only been in production for a little under a year and the push is finally on interally @ merc to promote the motor but the kicker is they don't even have a spec sheet...so I bit the bullet and purchased it today (btw, mine will be a new 07 motor dressed with new components but has to be advertised as reman since the heads are ported and can't be sold to the general public as new...or so I'm told). I'll keep you guys in the loop...already second guessing myself but hopefully everything will work out and I'll still keep a mid 60's wot, which is all I had before. It will be back to me on Sat just in time for the rain (gotta love the spring time in the NE) to run it on the Hudson...I'll post the GPS results later this weekend...or not if they're too horrible to discuss:).
 
I just ran a quick calculation with looks promising... I am not sure it is accurate as many things not taken into consideration such as friction (physical size did not change) - but just based on weight (which is a guess also) but should be close...

before/after
Engine Torque 420/390= 92.86% or 7.14% less
Base Weight? 3400/3100= 91.18% or 8.82% less

Difference 1.68% better weight loss vs power loss.

in other words:
before each ft/lb had to push 8.095 pounds of boat
after each ft/lb will need to push 7.948 pounds of boat.

you may ot see a difference or get lucky and gain 1 mph.

can't wait to find out how it ends :popcorn:
 
Good luck with the upgrade. I would like to see you post a few pictures of that engine before its in the hull. I would love to take a look at it.
Are you saying that you ordered the engine today ( Thrusday ) from Mercury and your installer has promised it installed and completed by Saturday?
 
Vinny, I'll do my best to get the pics, but I don't think it'll be til after it's dropped in. Yes, I ordered the motor yesterday morning through the shop and with any luck it will be here Friday - if that's the case, the shop told me I should be able to pick the boat up late Sat afternoon- worse case Tues. I'll keep you guys posted!
 
It really is - we have a annual run with 6 or 7 boats over to Block Island every Memorial Day weekend and the shop has been more than accomodating to help us get the boat back together. Ironically enough, my gimbal bearing needed to be replaced around the same time last year and he squeezed us in under the wire and turned the boat around in 2 1/2 days just in time to meet up with the other boats before we left- it was incredible (the owner/head mechanic got a bottle of grey goose then, and if they get me up and running before BI they can count on another!
Come to think of it, I might take a run up tomm afternoon if the motor came in and try to get some pics before they drop it in. Not being a gear head I am curious what everyone's thoughts will be - as for me, I'm keeping my fingers crossed!!! Thanks again for all the help guys..
 
Just got a call from the shop - they completed the swap and the only extra $$ was due to new risers ($430). It was water tested w/ 3 adults up to 5100rpm, 1/2 tank of fuel and read 64mph on the speedo (I took my gps out before I dropped it off)...I'm my way to pick her up and run it with the unit for a true reading, but I'm extremely happy with the turnaround (2 1/2 days!!) time and the premlinary results. I'll keep you posted!
 
you think he is still out on the water vinny p.???

hey checkmate25322 - how goes with the final results?

turning blue holding my breath, net-net are you happy with final results?
 
I was wondering the same thing What happened, how fast what kind of power did you have to bury it just to get out of the water?

This is must see tv and we have no result. Maybe he blew the motor and is drifting across the lake(just kidding):confused:
 
easy now... that 383 is a nice package.. i've installed quite a few of them, torqy and run extreemly well, and accept upgrades even better.. (wait till your warranty is up) your advantage is the weight ratio to the hp.. and new technology.. your gonna have to change props... but dont get your drawers in a roar.. that is a fine engine package, and i think you'll like it..
 
Happy,

I think we are all just waiting to see how it ran, what the results were.

Interested to see how the story turned out, with such a new motor application.

:thumb:
 
happy said:
... that 383 is a nice package.. your advantage is the weight ratio to the hp....
Click to expand...

I ran some numbers a few posts back and they look like it will net out the same roughly. +/- 2 mph. i am leaning toward for the better (1 mph faster). now i would like to see if my calc's are right since i did not take into account volume of water displaced, etc. just looked at weight.

:sssh:
 
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