Engine swap, 89 mercruiser 5.7 to 97 engine block

[blownmirage]

Hi, new to the forums, just bought a boat that someone didn't winterize, so of course cracked block, found a 97 5.7 block from a 97 tahoe, everything looks ok, but the only thing I can't figure out the fuel pump mounting, the 97 block is machined for a mechanical fuel pump, but not drilled all the way to the cam lobe for the fuel pump pushrod, has anyone used a block like this and drill fuel pump pushrod hole all the way or will this block not work, I will be taking the engine apart to rebuild, and clean any shavings if drilling will work, or do I just need to get a different block, thanks in advance

 

[cooter2506]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

You can add an electric fuel pump. It should be wired to run in the key start position and then thru an oil pressure switch to run when the key is in the run position. Someone here can proabably beat me to a diagram to post. I will search for one.

 

[blownmirage]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

I would like to keep it with the stock pump since I already have it and all the plumbing is safe, wife doesn't like modifications, (she doesn't swim) so I better just do it with the stock pump.

 

[cooter2506]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

Its not much of a modification since most if not all newer engines use an electric fuel pump. I would think sinc eyou are tearing engine down to do a rebuild anyway drilling it out wouldnt hurt. Make sure you use brass core(freeze) plugs and marine head gaskets on the rebuild.

 

[blownmirage]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

Looking for someone that has done this before and make sure nothing else is different that I am not noticing.

 

[lime4x4]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

I went from a 1986 to a 1998 chevy 350 vortec engine. Installed an electric fuel pump for carb. Unless u buy an engine that has the provision for the mechanical fuel pump or find an older engine. I wouldn't drill it. The hole would have to be perfect if not the fuel pump push rod will rub the block,bind or even break the camshaft.

 

[blownmirage]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

the mounting is all there, the holes are even drilled and tapped to hold pump, and the pushrod hole is drill up about 4 inches into block, looks like was going to be a standard block, also looks like possible freeze plug inside pushrod hole?

 

[bomar76]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

You will also be missing the oil drain back hole.
Redrilling that block to try to retrofit a mechanical pump is a really bad idea.
SBC blocks are all over the place dirt cheap. If you pay more than $50 for a good bare 1 piece main seasoned roller block you paid too much, and usually the seller will throw in the (to me) junk rods, pistons, crank, cam etc.

 

[blownmirage]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

the drain hole is partially drilled also, I am pulling it apart right now to see if can see anything more. I got the block for free, so would like to save money if possible

 

[blownmirage]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

will post pictures next week to see if anyone can help, thanks

 

[fstncrnrs]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

over the weekend i blew up 350 and am getting ready to try and replace with a new 5.3 i am concerned about the exhaust port shape on heads are you going to have the same issue. i have old style log manifolds

 

[Bondo]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

the drain hole is partially drilled also, I am pulling it apart right now to see if can see anything more. I got the block for free, so would like to save money if possible

Ayuh,..... Don't drill the block, either go electric, or find an older block,....

over the weekend i blew up 350 and am getting ready to try and replace with a new 5.3 i am concerned about the exhaust port shape on heads are you going to have the same issue. i have old style log manifolds

Ayuh,... The 5.3l is Not an option,.... It Won't work,....

 

[Bt Doctur]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

I`d check to see if the cam your using has the fuel pump lobe before you do any drilling.

 

[Freezer]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

You will also be missing the oil drain back hole.
Redrilling that block to try to retrofit a mechanical pump is a really bad idea.
SBC blocks are all over the place dirt cheap. If you pay more than $50 for a good bare 1 piece main seasoned roller block you paid too much, and usually the seller will throw in the (to me) junk rods, pistons, crank, cam etc.

I have a cracked 1999 Volvo Penta/GM 305/5.0l block as well and was going to try the same thing... buy a used truck 305 roller cam block and use it (about $200), but I'd rather buy a proper SBC block but can't seem to find one cheap (just the reman short blocks for about $1000 including shipping). Where would I look (or call) to find a used block for around $50 (as per above suggestion)?

 

[Don S]

Re: Engine swap, 89 mercruiser 5.7 to 97 engine block

Welcome to iboats.

You need to start your own thread Freezer, not just hijack an old thread. Be a good idea to post in the Volvo forum as well.