Repower

[CRANKIE]

I have a 1970 harkin marine olds 455<br />its bolted up to a velvet drive then into a<br />vee drive. The motor is junk (frost cracked)<br />i have a good 260 merc (350 chev)complet and running will the bell housing mate up?<br />anyone know?

 

[snapperbait]

Re: Repower

I don't think so... There were two bolt patterns that GM used, the chevy pattern and the "BOP" (buick,olds,pontiac) pattern...<br /><br />Keep an eye out on e-bay.. bell housings pop up on there from time to time..

 

[MooseHootie]

Re: Repower

BOP and Chevy are different but I race a car at the drag strip, and they make adapter plates to mate the chevy to the BOP pattern. I used a 500 horse power pontiac motor hooked to a chevy 400 transmission.

 

[Walt T]

Re: Repower

Keep looking for a 455. The 350 will not even come close to the power you got from that Olds. Look for a 1969-1970 vintage automotive Olds engine with a 4 bbl carb. If you drop a 350 in there, you will also have to change the prop, and you will then get blown away by the boats you used to beat. E mail me if you need help finding an engine.

 

[CRANKIE]

Re: Repower

Ok i have to rethink all this.<br />I found a bell housing to fit <br />now the prop?<br />455 to 350 100 less cubes but <br />how about horse power/tork ?

 

[Walt T]

Re: Repower

Are you kidding me? You have to ask? There is no replacement for displacement. Install that 350 and you will be disappointed. The 455 was legendary. Some of those babies came stock with 10.5:1 compression. Remember the Olds 442? It didnt have no stinkin 350 in it.<br />Really though, you have to compare apples to apples and you cant do that with a 350 and a 455. There is nothing at all wrong with the 350, it is a legend unto itself. Install it if you like, but retain all the 455 parts so you can drop a 455 in there next year. Let us know how it works out. I am certainly interested. You will need a prop change and possibly a gear ratio change in the V drive.

 

[navigator336]

Re: Repower

What are you putting that motor/drive into. The 455 Hardin Marine through the Borg Warner and Walter's??? vee-drive sounds like it is out of a flat bottom 18-21 footer. If you built the 350 some (to say 350 horse)you should be able to move that boat fast enough. At 260 horse, it will still go. However, as DW points out, it won't be any 455, and a prop pitch change will be in order. You could stroke the 350 to a 383 to get a good jump in torque.

 

[Walt T]

Re: Repower

The key here is Crankie has an engine already and wants it to work so that he doesnt have to spend too much money. If money werent the problem he'd buy a 455. It would cost more to build the 350 up to where it would begin to compare to the 455 than it would to buy and overhaul a stock 455.<br />Even if one can get the 350 into the 400 hp range, it still will not have the torque the 455 has at low rpm. This is what will require the gear and prop change.<br />More power to ya Crankie, it's not what I would do but that's easy for me to say when it's not my boat and my wallet we're talking about.

 

[CRANKIE]

Re: Repower

OK <br />350 GOES IN THIS SUMMER<br />455 GOES IN THIS WINTER<br />350 WILL GET NEW CAM AND HEADS<br />750 CFM HOLLEY HIGH ENERGY IGN SYSTEM<br />VELVET DRIVE IS 1TO1<br />ALL THESE PARTS ARE ON THE SHELF NOW<br />I WILL COLECT 455 PART IN SUMMER<br />I WILL LET YOU KNOW HOW IT ALL WORKS OUT<br />PS ANYONE KNOW A GOOD SITE ON HOW TO REFINISH MY WOOD HULL

 

[Bondo]

Re: Repower

Sounds Real Sweet......<br /><br />Except, your going to be way Over-Carbed......<br />A 600/650CFM is Plenty on a 350..............

 

[CRANKIE]

Re: Repower

I think the cam is of high lift and deration<br />to work with 750 carb. heads are cleaned up<br />port matched ect. At this point all these part are left over fron my rodding days so (very little cost). but the prop should i just try it<br />and see or change it now<br />the boat is 28 foot torjan.

 

[Bondo]

Re: Repower

A) High Lift,+ Duration is Not what's Needed for a Marine Engine........<br />Marine,+ RV Grinds are very Close to the same.......<br /><br />B) You're Still going to be Over Carbed.........<br />A 350cid@ 5000rpms can Only move Less than 550cfms....<br />A 600/650cfm will be Tunable......<br />You won't have enough Vacuum Signal with a 750cfm.......

 

[Walt T]

Re: Repower

Listen to Bondo. You will lose low end power by over carbureting and over camming. Do your research. You may save yourself a bundle.

 

[CRANKIE]

Re: Repower

Talked to a engine builder <br />thanks for your advice<br />will install rv cam (he traded me for my high lift cam) will use the stock 260 merc carb<br />thanks so far will keep you posted