Questions for the mechanics out there... EDIT

F

Fish Guts

Member
Member
Joined
Jun 13, 2002
RO Number
8982
Messages
96
Looking at a replacement engine for my 23' Regal Ambassador. The engine I'm looking at has these cam specs, would it be okay?

Hydraulic Roller Camshaft Lift: .414'' Intake, .428'' Exhaust Duration at .050'': 191В° Intake, 196В° Exhaust

Or should I take the cam out of my current 5.7

ETA... It's a truck engine.

EDIT... I am using 5w-30 for break-in, when I change the oil, what weight should I use, what Merc recommends or what GM Goodwrench recommends?
 
That's not a particularly aggressive cam. A little more info on the engine might help.

I've always had this reasoning, if you're gonna replace the engine, why not add some power.

OOP's! Re-read, you have roller cam, Different story will have to review roller specs. One reason being, the roller allows earlier opening and later closing which increases the duration( and air flow) when the valve is open. Flat tappet cams do this by lift only
 
Ya know Charlie, I didn't even realize it was a roller cam either. So I couldn't even use my cam in the new engine, flat tappet. Let me add a link to another engine I'm looking at. If I swap the cam with mine... would it work? My cam being a true marine cam. I'm getting a fresh water cooling system and using all my external parts. starter,alt,carb etc. Also thinking about moving to an electronic ignition vs. the tbolt 4 that I have now.

http://www.jegs.com/i/Chevrolet-Performance/809/12568758/10002/-1

Thanks,
 
Ayuh,.... Any one of the 3 cams in this discussion will run just fine in a boat motor,...

Ya get into trouble with cams in boat motors, when ya get to the Hot Rod cams,...

There's little to no differences when usin' standard automotive, truck, Rv, or marine rated cams,...
So long as ya pick a cam that makes horsepower from idle to 'bout 5,000 rpms, you won't have any problems,...

Personally, I'd go with the roller cam in the truck motor,.....

side-note,...
Hi Charlie, long time no chat,...
Just happened to find the link to here, 'n dropped in,...
This place looks like a ghost town, page 1 in the motor's forum goes all the way back to last summer,...
Back when I was hangin' out here, page 1 turned over in a few hours most days,....
 
Hey Bill, yeah, it's been gettin' pretty slow. Not much interest in engine stuff either.

Richard, As bill said, the roller cam would be the preferred motor to work with.
As far as those mr goodwrench motors go, I know a couple mechanics that used them and were happy but they had 18' and 20' footers and all they did was fishing, not skiing.

Cams only cost around $100-$120 so it's not worth using an old cam. I get comp cams xtreme cams. Look at the specs to make torque around 2000-2200 RPM with max HP around 4800-5000 RPM. Comp Cams has a good selection of dual pattern marine specific cams.
 
Yeah, I don't pull any skiers. This is a small cruiser, just need something to get me around the bay here. For about 600 more I can get a "marine" engine, just not sure it's much different besides the head gaskets, but if I'm putting the fresh water cooling in it it's not necessary.
 
I think they already use brass freeze plugs on those engines and FWC engines really don't need SS head gaskets though they cost about $50. You could get that truck engine and add a cam and even head gaskets as long as you're there. You'll loose a little power using aftermarket head gaskets but a cam upgrade can make up for that.

On the other hand you can just drop that goodwrench engine in right out of the box. You're likely to get some flack from guys if you don't use a marine engine but I bet none of them ever built an engine before. I've built a half dozen marine engines and the cam is the only difference. I don't think anyone even uses forged pistons these days...or needs to.
 
I agree with adding a few HP. At Admiral's suggestion (and a Suggestion from an Admiral is always an Order...) I had a MerC shop replace our old 5.7EFI with a MerC "Reman" 5.7 bored .040 and called a "357." Our Sea Ray manual called the 5.7 a 220-HP engine, but at the prop shaft. There was a 5.7LX at 250, again prop shaft HP. But I haven't seen anything other than Outboards rated at the Prop, always at the Crank. One MerC dealer told me the 5.7EFI was 250 HP at the Crank. I'll never know, but the 357 is rated 275 HP, at whatever. 25 or maybe 50 HP more than the old engine. But hear this: It Feels Like 100 HP More! It can hold plane with 4 POB at 3000 RPM. Used to take 3200 for 3 POB. Tops out at 40 KT vs 35. Turns 4800 RPM vs 4600. Those are the respective RPM ratings for the two engines. BUT!!! The 357 is running a 23 Pitch Black Max aluminum 3-blade vs a 19 Pitch Vengeance stainless 3-blade. It's like a whole different boat.

From what I understand, new 350/5.7 engines are still being built. But 454/7.4 engines, no. Friend bought what was listed as a New Marine 454. MANY problems including tuliped valves and water in the cylinders. He pulled the heads to have them worked, and the shop said the engine did not have Marine Head Gaskets. If this is what truly happened, I am VERY concerned about "Marine" engines from automotive sources. There's more to a marine engine than the freeze plugs.

I'm glad the Admiral made her "Suggestion." I paid more, but I'm out boating and my friend's been wrenching. Finally gave up and bought a Wellcraft walkaround with a 250 Yammie OB.
 
Yeah, I'm really going back and forth on this... these are the specs from the New GM engine, What do you all think? Kinda worried about the small chamber size. Think this engine has enough?

This 350 long block assembly was engineered as a drop-in replacement for the GM family of light-duty trucks (e.g. 1987-95 Chevy/GMC 1500/2500). It features a flat tappet hydraulic camshaft and a swirled port intake design.

Specifications
Horsepower: 210 at 4000 RPM
Torque: 300 ft/lbs at 2800 RPM
Cast Iron Block (2-Bolt Main Caps, 1-Piece Rear Seal)
1-Piece Nodular Iron Crankshaft
Dished Hypereutectic Pistons
Powdered Metal Connecting Rods
Compression Ratio: 9.4 to 1
Morse Link-Type Timing Chain
Flat Tappet Hydraulic Camshaft
Camshaft Lift: .382" Intake, .402" Exhaust
Camshaft Duration at .050": 165° Intake, 174° Exhaust
Valve Size: 1.94" Intake, 1.50" Exhaust
Centerbolt Cylinder Heads (65.3cc Chambers)
 
I'm not qualified to comment on engine details. Again, glad I had it replaced with a MerC product. That isn't to say you should or that's the only way to go. Charlie's our Engine Builder here, your best bet when it comes to details.
 
The point where max HP is registered is where the WOT is rated. HP drops off after WOT. 2800 for max torque is only slightly higher than most marine cams but fine if you aren't trying to pull a skier.

That's a pretty mild cam. You could look at different cam mfg and see what specs won't require special parts or machining and get a stronger cam. I expect you have a Gen I small block chevy (1962-1998) flat tappet hydraulic cam. You's have to do some investigating (learning) about cams to see what upgrade you can use. There are little tricks they've come up with to increase valve lift (special springs) without special machning.

After doing a number of engine builds, I've found out, to feel any real performance increase, you'll need around 100 HP...which is actually an increase in torque that you're looking for.

Sounds to me, JD's engine would be an excellent choice...But I suspect he paid for it[:P]
 
http://www.ebay.com/itm/Mercruiser-357-Alpha-4v-275-HP-Engine-5-7-5-7l-350-mag-magnum-275hp-865108R88-/400184730176
I think the actual retail is about $6500
s-l500.jpg

As you can see, it comes VERY complete. That can be good or bad. If you KNOW SUREFIRE CERTAIN that your accessories, like manifolds (including intake!), carb, ignition, coupler... are all good, then this complete engine (sometimes called a bobtail engine) is overkill. But it's typical for a defective accessory to be the cause of death for the engine being replaced. Then it gets installed on the new engine and kills that one. Again, I'm thankful for the Admiral's Suggestion.
 
So, I got the engine... Next question. Do I, should I add the oil baffle to the new engine? This would require removing the main bearing cap bolts to replace with the longer for the baffle. If so, one at a time and torque, or okay to do both from a cap and replace?

ETA... Is it necessary?
 
I can only tell you what I was advised on a car. I wanted to drop the rod caps, pull the pistons, hone cylinders and replace stuck rings. I was told to buy NEW bearing shells. The WHY is that they should only be crushed into place (by torquing the cap bolts) ONCE.

I don't know what GM and the various rebuilders are doing, but my car hadn't been apart. I learned that each cap bearing was matched to the exact diameter of its respective crankshaft journal, according to a code stamped someplace.

All this suggests leaving those bearings alone, leaving the tray off.
 
One other thing... Of course. My dipstick tube is about 1/2" too long. I guess I had the 5 1/2 qt. pan and this engine has a 4 1/2 qt pan. I am going to look for a shorter dipstick tube, vs. changing pan and pump. Or should I just change them out? I really just wanted to put the accessories on and drop it in.
 
Some oil pans have 'baffles' built in. It's just a plate that's tack welded to cover the sump area. It's purpose is to reduce any splash and keep oil in the sump so the oil pump has oil to feed it. Get as big an oil pan as available. Stock oil pump has a pick-up that will rotate down if needed. The large oil pan has a more square sump as opposed to a slightly angled bottom. I never measured but the two sumps may be the same depth. If you have to change or move the pick-up, stick some clay to the bottom of the pick-up and bolt up the pan. The clay should squish to about 1/4", then tack weld the pick-up tube...or JB weld it.It's gotta be real clean. Get a center punch and ding the surface of the pick-up tube that goes into the pump body. Get a file or coarse sand paper to scuff the tube. The dings gives an area to build a little bulk for the JBweld.
Use clay for changing/measuring the dipstick tube and dip stick, too.

As for the main and rod bearings. You have to torque and loosen a couple times for each bearing when you measure bearing clearance using plastigauge...which is just wax that you measure the width that it gets squeezed to.
 
Sounds like a lot more work than I wanted to do Charlie. Could I just cut down the dipstick tube and dipstick the 1/2" and raise the full mark on the stick a 1/2"?
 
I would use what Merc recommends, a "Normal" truck engine spends a lot of time at <2000 RPM on the highway. A Boat spends time in the 3000-4000 RPM range, use what the application dictates.
 
You must log in or register to reply here.
Back
Top