Marinize GM 305

[int76]

So with little response to my other threads I think Ive figured out the route id like to go to fix my boat (cracked block). Its a 99 Glaston with a GM305 5.0L Volvo Penta motor. Ive found a local engine reman/machine shop who sells GM 305 complete reman short blocks for pretty cheap and Im wondering what all I need to do to marinize this motor? From what I gathered from reading I need to change the freeze plugs and the head gaskets, is this correct? Ive also read about changing cams, is this necessary? or can I just replace the freeze plugs/head gaskets and put my heads, exhaust/intake manifold etc off my motor and be good to go? Just want to clear everything up before I pull the trigger on this short block....Thanks - Josh

 

[starsnstripers]

Re: Marinize GM 305

You need all your marine accesories of coarse, alt,starter,Fuel pump, dist, carb, etc. abd yes if your going to marinize it do the cam! You don't "have" to but there's a couple of reasons why they're different. 1 they help so your motor doesn't get water ingestion 2 higher torque moving a boat is alot different from moving an auto. Not enough torque makes for SLOOOOW getting going and getting up on plane. You choose.

 

[int76]

Re: Marinize GM 305

Well here is a little more on my situation....my motor apprently blew a head gasket/cracked the block in between the cylinders (no water in oil) with 99.9 hrs on the motor. Thinking I had possibly just blew a head gasket or cracked a head I purchased a spare long block (freeze cracked block casing) with 65 hrs on it. So I have 2 sets of good pistons/cam/heads/etc to work with. My local engine reman place has a fresh rebuilt 305 small block for $355. From what I can tell on rapido which they dont even have the 96+ GM 305 listed their reman marine 305 is $1200+ not including gasket set, which obviously is WAYYY more than my local auto 305 remain. With 2 good heads/cams I dont see any reason to purchase the marine 305 over the local (no shipping as well) auto 305 which has a warranty as well. To be honest Ive never done an engine swap much less a cam swap so I will be enlisting the help of mechanic buddies to get this all accomplished. Seeing as though I have to buy the gasket set regardless of which route I go, IMO I dont see the need to spend the extra $900 from rapidomarine if I have 2 good cams in my possession to use?!??! From a best cost scenario I think the $355 reman auto small block w/ my available parts is my best option.....opinions welcome as always....

 

[int76]

Re: Marinize GM 305

Bump.......

 

[Fishermark]

Re: Marinize GM 305

I cannot imagine a $355 reman engine. I would certainly ask a few questions of the shop - like...

How do they define "reman?" What did they do specifically to this block?

Are you sure the heads you have are good?

What kind of cams are these? If you reuse any of the cams, be sure to buy new lifters.

 

[bruceb58]

Re: Marinize GM 305

Even if it was $800 more, I would put the 350 in it but I think there is something missing here. No way they can rebuild an engine and do it right for $355.

 

[OldNBold51]

Re: Marinize GM 305

Having just gone thru the same thing, the differences are:1) head gaskets and freeze plugs need to be Marine. 2) the engine bearings need to be harder than stock...cam bearings, crank bearings, rod bearings. Race engine bearings will work. 3) use your original marine camshaft as the cam torque spec's work better than auto.

The bearing issue is important as you're building an engine to run at higher rpms than an auto usually operates continuously.

Another thing to ask is are the installed pistons matching. If the weight or compression varies due to mismatched pistons then your higher rpms will give more vibration etc. Many of the "engine exchange" shops have mis-matched pistons...stuff they pulled out of blown engines keeping the pistons that were still OK.

 

[starsnstripers]

Re: Marinize GM 305

Harder bearings in marine applications? I never knew/heard of that. Interesting.

 

[int76]

Re: Marinize GM 305

What kind of cams are these? If you reuse any of the cams, be sure to buy new lifters.

I have 2 Volvo 5.0Gl long blocks, which have the standard marine cam in them I would imagine. If both motors have 65hrs and 100hrs could I not just reuse my current lifters? I called the reman supplier and its $355 without lifters or $550 with lifters and oil pump(which I couldnt use the pump anyways)

Not saying it isn't possible but I would be asking a LOT of questions about this engine. I simply see no way to do a quality rebuild for that amount. Sounds to me like they honed the cyls. and stuck fresh rings in it. ($300 is about what that would cost.)

I was referred to this reman supplier from the lead mechanic at my work ( I work at Caterpillar). He recommended them and has used them on several occasions and I vouch for his work so I wouldnt think he would send me in the wrong direction. The business has been around awhile as well so they must be doing something right. I too thought that was way too cheap but apparently it is legitimate...here is the link to their site. http://www.citymotorsupply.com/

 

[180shabah]

Re: Marinize GM 305

Harder bearings in marine applications? I never knew/heard of that. Interesting.

Cause it is pure BS!

 

[Bondo]

Re: Marinize GM 305

I called the reman supplier and its $355 without lifters or $550 with lifters and oil pump(which I couldnt use the pump anyways)

Ayuh,... You're talkin' a Different Language than We are or Something,..

What the 'ell are you buying for $355. anyways...
It sounds like you're gettin' a BARE Block,... Nothing more...
Definitely, NOT a Reman Motor, Long or Short block....
And,... $355. is Hi-way Robbery for a Bare block,....
I bought a cherry low mileage 4.3 block that was torn down, cleaned,+ sonic tested for $100....
V8s are Cheaper yet, because they're more common....

There's more Bullship in this thread than just the Extra Hard Marine Motor Bearings....

 

[Bt Doctur]

Re: Marinize GM 305

Unless you kept the lifters matched to each cam`s lobe ,you have 1 option.
a new cam with new lifters

 

[brendanstl]

Re: Marinize GM 305

LOL..... Harder bearings? This is getting deep, go buy yourself a running motor in a junkyard out of a truck, strip it down use the crank and pistons if they are ok and build up from there. I just bought a running 350 from a van and the casting numbers from the cranks, rods and pistons were the same as the casting numbers from my mercruiser along with the valves, pushrods, rocker arms and springs the only thing that was different was the cam. I dont think I had the harder bearings though, maybe I should change them out.......

 

[brendanstl]

Re: Marinize GM 305

Unless you kept the lifters matched to each cam`s lobe ,you have 1 option.
a new cam with new lifters

You think so if he only had 99 hours on them? My machinist said roll with them wherever if you have low hours and they arent visibly worn.

 

[int76]

Re: Marinize GM 305

Ayuh,... You're talkin' a Different Language than We are or Something,..

What the 'ell are you buying for $355. anyways...
It sounds like you're gettin' a BARE Block,... Nothing more...
Definitely, NOT a Reman Motor, Long or Short block....
And,... $355. is Hi-way Robbery for a Bare block,....
I bought a cherry low mileage 4.3 block that was torn down, cleaned,+ sonic tested for $100....
V8s are Cheaper yet, because they're more common....

There's more Bullship in this thread than just the Extra Hard Marine Motor Bearings....

From their website and from calling and verifying from them its a complete reman short block for $355 and $550 for a reman short block "assembly" which includes new lifters and oil pump...its not just a bare block....

You think so if he only had 99 hours on them? My machinist said roll with them wherever if you have low hours and they arent visibly worn.

as stated I have 1 99 305 with 99hrs with cracked block between cylinders everything else ok less a busted piston and 1 03 305 with 65 hrs with freeze cracked block case everything else ok. So technically I should have plenty of spare parts to put this thing together. I honestly dont see why I couldnt use one of the marine cams/lifters in the new short block?!? then again im not engine tech by any means...

 

[roostonu]

Re: Marinize GM 305

I am a mechanic and I would stay far away from a $350 short block. I have seen what some people's idea of a reman engine is. And it aint pretty.

 

[Bondo]

Re: Marinize GM 305

its not just a bare block....

Ayuh,... So what IS included.....

A Short Block is a Complete motor, less the Heads,+ Tin....

 

[bomar76]

Re: Marinize GM 305

For $355 I'm tempted to buy one myself just for the laugh my friends and I would get out of it.

 

[int76]

Re: Marinize GM 305

Ayuh,... So what IS included.....

A Short Block is a Complete motor, less the Heads,+ Tin....

From my understanding it is complete minus heads,lifters, oil pump...

Im with you guys I definitely feel $355 is extremely cheap for a complete reman short block but the company has been in business for 60+years so obviously they are doing something right, as well as my lead mechanic refering them. I guess ill just have to see for myself and drive up there to check it out....

...but back on topic if this short block is indeed legit all I need to do to "marinize" it is swap out my marine cam/lifters, change to brass freeze plugs and use marine head gaskets? also anybody know where I can find a complete overhaul marine gasket set for this motor? all I can find them for is the pre-96 gen1 305s?!?!

 

[Fishermark]

Re: Marinize GM 305

...but back on topic if this short block is indeed legit all I need to do to "marinize" it is swap out my marine cam/lifters, change to brass freeze plugs and use marine head gaskets?

That is correct.

If you use your old cam, just be sure to keep the lifters matched up with the cam - in other words, make sure each individual lifter goes back onto the same exact cam lobe.

Do yourself a favor and simply buy a Fel Pro gasket set. You can confirm with the company, but I am pretty sure that all of their head gaskets use composite material and stainless steel. Perfectly fine for a marine environment.