Push rods for 1978 Mercruiser I/O

[George Marks]

I had a boat given to me in pieces. I have found that the push rods are different sizes is this common in a 1978 2.5 120/140 HP. If so which is which.

 

[Don S]

Re: Push rods for 1978 Mercruiser I/O

They should all be the same size. Are you sure you don't have a 470? It's also a 4 cylinder engine, but it uses different size pushrods.

 

[George Marks]

Re: Push rods for 1978 Mercruiser I/O

It may be first time I have owned a boat. how do I tell? which rod is the exhaust.

 

[Bt Doctur]

Re: Push rods for 1978 Mercruiser I/O

is this a cast iron motor or an aluminum motor with a heat exchanger

 

[George Marks]

Re: Push rods for 1978 Mercruiser I/O

cast

 

[Bt Doctur]

Re: Push rods for 1978 Mercruiser I/O

check your messages

 

[Don S]

Re: Push rods for 1978 Mercruiser I/O

It may be first time I have owned a boat. how do I tell? which rod is the exhaust.

We first need to make sure which engine you have. A 120 is a cast iron engine, a 470 is a cast aluminum engine. Not sure you could tell by looking if it's aluminum or iron.
Post a picture of your engine. That will take away all doubts.
PS the push rod length on a 470 has nothing to do with intake or exhaust. It's all about measurement.
The 120's and 140's all have the same length push rods both intake and exhaust are exactly the same.

 

[George Marks]

Re: Push rods for 1978 Mercruiser I/O

ok

 

[Bt Doctur]

Re: Push rods for 1978 Mercruiser I/O

Thats the typical 120,140 GM motor .All the pushrods are the same length.

 

[George Marks]

Re: Push rods for 1978 Mercruiser I/O

ok i guess i am mistakin then thanks