Another Nicasil ?

[Ally 1988]

Im thinking about having some engine work done not sure yet but you guys can help with your 2 cents. I have 1995 2.5 260 efi 125psi +/- 5 all around and soon to have my a48 box back from rapair (currently i think says a43 or 45 can't really read it) but I'm thinking about having some other things done realize Im not a racer just your average go fast lake boat. I have one steel sleeve in my otherwise all nicasil motor its been in there 4 years now otherwise it is bone stock to my knowledge. I want to have my reed plates angle cut Dry stack exhaust lighten flywheel and maybe go so far as to lighten rods and pistons but if i go that far would you replace the steel sleeve with nicasil realizing of course there could be a need for more work but thats all I hope I have to done.

well thats maybe all i can afford anyway.

[Balzy]

and have him change that sleeve to Nic. Have him check and straighten all the bores right away. Maybe even have him put his newer top girdle rings in it. He can also clean up the exhaust chest a little bit for you right away without loosing much if any bottom end. Mine will be going to Jim this winter just to be measured and checked before I put it back together this year. Needs rings again.

[Liqui-Fly]

Reeds aren't going to do anything for you. Sounds like maybe you could use some rings too. Fresh is 135 psi typically. But definitely cut the heads.

David

[Ally 1988]

should i change the one cylinder that is steel back to nicasil or just rering other than send it out for straighteniing i agree with the other post about nicasil heat exchange. but i made a 90 mile run at 80 mph aside for stopping for fuel there was no problems other than i ruined another lower unit. Is this something to be concerned with or just do what i want to due and let it ride.

[Balzy]

due to the heat exchange issue.

[WhatJerryWouldSay]

Dont fix it!:D

[ImbadBob]

I rebuilt my 260 last winter, cut the heads .100. Did some minor clean up in the exaust. I mix 25/75 race feul to 93, I gained 400 rpm and a whole bunch of hole shot. My 260 also has 1 steel hole seems to work O.K. Have built a skid plate for your 2002 yet? My 2003 likes it alot. Bob

[Ally 1988]

true but it is down on rpms a little aside from just the heat 7750 down now to barely making 7000 with 29 mazco and 1.87 gears just thought since summer is nearing end might be a good thing to do during the sort of off season

[ImbadBob]

Have you checked your fuel injectors and final filter ? Loss of fuel pres. or sloppy spray from injectors can kill rpms. I changed ecu, stator trigger, power packs, no change . I finally got to borrow a DDT #5&6 injectors looked like the spray from a water pistol. Replaced them and got the power back. Good luck Bob

[Hammer]

I know for fact Dr Bruce Tripp ran two races in ODBA- top dog in three classes- this year with two steel sleeves in one of his motors, I know its drag racing and we don't have a heat issue ( we actually Want to build heat) I would send it to Ruck,J Smith, Tommy Dunn ect. and let them help you decide.

[Greg Moss]

If you are looking for more bang for the buck your list of mods makes NO sence. You can spend your hard earned money on different things than you have listed and get a real performance increase. Have the heads cut to give you 150lbs. Have the exhaust cut and the rod slots. You can balance the rods and pistons but you will for a lake boat see no difference other than the oo-ha factor with cutting up the flywheel, save that money to have the block cut. I run all steel bores and don't have any hjeat problems. Never have. Nic block may transfer heat better but the way Merc cools their motor they need all the help they can get. Have the reed plate angle cut. all that should give you a real feel of performance increace.

[Ally 1988]

thats what i was hoping for your suggestions Im no mechanic so what ever i do it will be sent out for the work. Hopefully soon. Thanks for all the input. Injectors were the first thing I had checked then replaced 02 sensor then fuel filter changed boxes a45 to a48back to a45 no change on the a45 box I can't read exactly what it is it could be a a43 but the 3 or 5 is smeared I know it is rev limited because with my 24 prop it will find it quickly at about 7700 or so.Changed plugs and wires because I dropped one in about 30' water.Something else win I had sleave put in that was the first time engine had been into and they replaced crank and sleeve rerung that one cylinder and sent it on its way. other than that same old everything else is still there from mercury. as far i know? Hours on powerhead who knows I run it close to 3 times a week for about 4 yrs. now. Im not really complaining about its performance its just that i have got to used to it and wont a little more. Your probably right about heat transfer though made 90 mile trip earlier this year no problems other than destroying my lower unit.
and mind you the entire trip was at 80 plus mph for the most part.
only stopping long enough to refuel.

[Greg Moss]

How small a tank you got that you cann't run 90 miles with out refueling?

[Ally 1988]

I believe its 20 something 24 25 but actually not sure all I did was take extra ten gallons for just in case i probably just burned a tank but it was not worth taking a chance. Crossing lake George on a really bad day very windy. We went from palatka florida to the glenn.

[MERCMAN]

dont cut your heads to 150 til you get the motor rebuilt because of it being low on compression now , it might not even be low you might have the wrong head gaskets on it. if you are considering modifications to your block you should go back with a nicom cylinder. most stock motors and a few modified motors have no issues with the sleeve , ive run them every way. but the open faced wiseco piston you have now doesnt work well in the steel cylinder like the mahles did , another thing your going to have to consider is the fact that you have some dud pistons in your motor. you need to consider what your budget is going to be , you might be better off rebuilding your motor the proper way then worrying about mods , if your budget is big then never mind right? you might be replacing some pistons , or you might just need to have them pinned. the piston is a key consideration in your motor. obviously if you have a good budget heres a list of the most commonly done things for an average lake racer motor , remember i said "average"


1- exhaust chest "mildly" milled
2- cylinder heads cut to provide 145 lbs of compression
3- new reeds are a must in a rebuild (age on your motor)
4- angle cut reed plate ( do not bore your airhorn)
5- block blueprinted
6- pin all pistons if bad replace as necessary.
7- balance all rods and pistons (no need to lighten)
8- possibly lighten your flywheel depending on what rig your running.
9- in your case have the a-48 chip put in your 11350 box.
10- dry stack (once again your choice)
the list goes on and on depending on your specific needs.

there are pro's and cons to everything you do to your engine , if everything is explained to you properly you will easily be able to make these decisions without alot of thought.

if you need any advice call me anytime , i would personally go to jay smith for the machine work because hes a one stop shop for everything you will need done other than a sleeve. HE is fast and has no problem talking to you about any questions you might have about modifications to your engine , his work is excellent. he has done alot of machine work for me and i have never had any complaints on his work. i wouldnt use anyone else myself. give him a call.
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