5.7 vs 4.3 Mercruiser

[Croppyboy]

Hi gang, <br />I just found this site, thanks to those that run it and those that supply the information.<br />My question/comment:<br />I am looking at two used boats to buy. Coincidentally they both are Starcraft. The first is a 1995 20 ft bowrider with the 5.7 V8. I do not yet know the HP (I'm looking at it on Saturday) the second is a 1999 18 ft bowrider with the 4.3, 195 HP. Both are about the same price. I usually have 4 people in the boat and we ski, tube and wake board. Also some cruising.<br />Any suggestions/comments if I will be under powered with the 4.3?<br />Thanks.

 

[Belchy]

Re: 5.7 vs 4.3 Mercruiser

Welcome to iboats!!<br /><br />I have had experience with two different bowrides, pulling skiiers tubers etc. One was a Cadorette with a 4.3 OMC Cobra and it had no problem crusing with 4-5 people or pulling upwards of 6 water skiers. The other boat is an 18 ft. Four Winns, with a 4.3 Volvo Penta. With the price of gas I know that a 5.7 is going to be much harder and heavier than a 4.3. I personaly don't think that you would be under powered with a 4.3<br /><br /><br />Belchy

 

[jimmbo]

Re: 5.7 vs 4.3 Mercruiser

Once you experience the V8 and compare it to the V6 you won't be satisfied with the smaller engine. The bigger engine has lots more torque which will make the boat take off more like an outboard. With 4 people on board the extra 2 ft of boat will be welcomed too.

 

[navigator336]

Re: 5.7 vs 4.3 Mercruiser

If you are going to ski, it is much easier on the skier if you have more power (unless they are light). You also want the bow down quickly. In my opinion, for skiing always go for more power. Every boat is different, but in many cases the 5.7 will burn about the same fuel as the 4.3 as you can turn a bigger prop at lower rpms and be closer to the optimum rpm (torque) range at skiing speeds.

 

[Croppyboy]

Re: 5.7 vs 4.3 Mercruiser

Does anyone know what the horse power might be on the 5.7L Mercruiser engine? BUC boat pricing showed 180, but that seems to low.

 

[wvit100]

Re: 5.7 vs 4.3 Mercruiser

I have a '95 5.7, it is rated in the boat's manual at 235 hp. with the 4 barrel carb. I have seen the same motor listed in other manuals at 250 hp.

 

[navigator336]

Re: 5.7 vs 4.3 Mercruiser

I would guess it is 235, 250 or 260.

 

[Northern Eclipse]

Re: 5.7 vs 4.3 Mercruiser

The 5.7 could be a 2bbl motor which I believe as been rated as low has 210hp or 4bbl rated at 250, or a 350mag at 260-300 depending on fuel delivery, such as carbed or fuel injected. Note that hp is rated at the propshaft ei: 260hp is 250php. Lets assume the 18ft with 195hp v6 would be faily much the same has the 20ft with 210hp 5.7, depending in weight differance, best way to find out is water test both boats, I myself have a 20ft Wellcraft with 350 mag, fuel burn is decent at cruise speeds 3000-3500 rpm, My friend who has a 18 ft cadorette with 175hp v6 burns almost the same amount of fuel I do.

 

[steinjo]

Re: 5.7 vs 4.3 Mercruiser

Originally posted by wvit100:<br /> I have a '95 5.7, it is rated in the boat's manual at 235 hp. with the 4 barrel carb. I have seen the same motor listed in other manuals at 250 hp.

wvit100. You know a good Mercruiser mechanic around Lake Wylie? I've got a 5.7 litre 1996

 

[murphini]

Re: 5.7 vs 4.3 Mercruiser

Good article last year in Boating Magazine about the difference between Horsepower and Torque. Torque is what you need to pull/yank the skiier out of the water as your engine revs from 600rpm to 3000rpm. Foot-pounds of torque, esp at low RPMs are the key, not the ultimate horsepower which may come at a higher RPM when acceleration is not as fast. <br /><br />You should have more torque with the V8 than the V6. Someone correct me if I'm wrong there...<br /><br />I have a 20' bowrider with a 5.0 v8 and it pulls like a banshee. I figure 5.7 at 20' would be even beefier. And yes, you want 2 more feet of length. You'll soon wish your 20' was 22'....

 

[Croppyboy]

Re: 5.7 vs 4.3 Mercruiser

I purchased the 20' with the 5.7. I put it in the water (here in WI), but the weather has not cooperated for a all day ride yet.<br />Thanks to all of you for your help.