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Discussion Starter #1
Dave,
Sorry we had to talk on such bad news. I ran some numbers on the seat duration to see what overlap numbers looked liked as we did take in account on this build that you wanted a sound build that could use the short risers.

Mercury Mag 502 engine with cast iron manifolds has 57 degrees of overlap
HP500 Carb Engine and the shorts has 68 degrees of overlap
28Eliminators cam has 59.5 degrees

I called a ex Crane guy that was at Crane during the 90's and asked him about 60 degrees overlap and injesting water. He said 60 is no issue.
 

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Dave,
Sorry we had to talk on such bad news. I ran some numbers on the seat duration to see what overlap numbers looked liked as we did take in account on this build that you wanted a sound build that could use the short risers.
Mercury Mag 502 engine with cast iron manifolds has 57 degrees of overlap
HP500 Carb Engine and the shorts has 68 degrees of overlap
28Eliminators cam has 59.5 degrees
Bold and in red above is incorrect. You've stated the overlap at .004" with the HP500 cam instead of at .006" like the Mag Cam and 28 Eliminator's cam. The HP500 cam has 60º overlap at .006". Your statement is 8º high.

From my notes, here are the specs on the Mag Cam and HP500 cam. Seat/overlap #'s at .006" as is 28Eliminator's.

Notice the overlap at .050" as I'll get into why on very next post.

Merc Mag Roller
Merc# 431-850478 / GM#12551622
.006" 288º/288º Overlap 57º
.050” 225º/225º Overlap -6º
Lift .483”/. 483”
ICL 109º
LSA 115.5º

Merc HP500 Carb
Crane Gen VI#169611 Grind#HR-284-2S-10IG
276º, 284º At .006” 60ºOverlap
222º, 230º At .050” 6ºOverlap
Lift with 1.7 .576” , .598”
ICL 105, ECL 115
LSA 110

Now, here : http://www.performanceboats.com/dyno/87614-big-thanks-chris-straub.html#post1425675
28Eliminator stated his cam specs as quote:

Here it is in a nutshell;

8.9:1, .030 over 502 GM block (Gen V). Bored and honed with Plates, plateau honed, square decked .015 - .019. Align bored. GM forged crank, micro polished only. Dimple rods, resized and shot peened. SRP 4.500 -3cc dome pistons, JE rings. Pistons are .005 in the hole. Melling HV 1077 pump, standard press. Changed bypass valve to 30# in block and remote pad

Heads are stock 088 castings. I did an extensive bowl blend and opened up SS radius, polished the chambers, 5 angle int, full radius exh, 122 cc chambers (thanks Merc), Milled .010, .100 longer valves with 11/32 stems (REV's), 2.25 int, 1.88 ex. Flowed 358 @ .700. Morel lifters, Crane gold rockers

Dart intake (HP500), Gil exhaust, 800 cfm Holley, MSD ignition system.

Straub Hyd Roller (Squishy ) 650/603, 228/242
Looking up Bullet's Lobes that are as stated by 28Eliminator above in Bold + Red

we have the following:

Duration at .006" 284°, 300° Overlap 68° 8° More Overlap than HP500 at .006"
Duration at .050" 228°, 242° Overlap 11° 5° More Overlap than HP500 at .050"
.3823" Lobe Lift .3550" Lobe Lift
.6499" valve lift w/1.7 .6035" valve lift w/1.7
112° LSA
 

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Discussion Starter #3
Bold and in red above is incorrect. You've stated the overlap at .004" with the HP500 cam instead of at .006" like the Mag Cam and 28 Eliminator's cam. The HP500 cam has 60º overlap at .006". Your statement is 8º high.

From my notes, here are the specs on the Mag Cam and HP500 cam. Seat/overlap #'s at .006" as is 28Eliminator's.

Notice the overlap at .050" as I'll get into why on very next post.

Merc Mag Roller
Merc# 431-850478 / GM#12551622
.006" 288º/288º Overlap 57º
.050” 225º/225º Overlap -6º
Lift .483”/. 483”
ICL 109º
LSA 115.5º

Merc HP500 Carb
Crane Gen VI#169611 Grind#HR-284-2S-10IG
276º, 284º At .006” 60ºOverlap
222º, 230º At .050” 6ºOverlap
Lift with 1.7 .576” , .598”
ICL 105, ECL 115
LSA 110

Now, here : http://www.performanceboats.com/dyno/87614-big-thanks-chris-straub.html#post1425675
28Eliminator stated his cam specs as quote:



Looking up Bullet's Lobes that are as stated by 28Eliminator above in Bold + Red

we have the following:

Duration at .006" 284°, 300° Overlap 68° 8° More Overlap than HP500 at .006"
Duration at .050" 228°, 242° Overlap 11° 5° More Overlap than HP500 at .050"
.3823" Lobe Lift .3550" Lobe Lift
.6499" valve lift w/1.7 .6035" valve lift w/1.7
112° LSA
Wrong lobes Scotty. The engine shows not sign of reversion. If had reversion the tops of the pistons would be clean along with the chambers. The engine dropped a seat and the water entered then.
 

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Dave,

I called a ex Crane guy that was at Crane during the 90's and asked him about 60 degrees overlap and injesting water. He said 60 is no issue.
I have a copy of Crane's Newsletter on this very subject. They actually talked about overlap at .050" not seat overlap. Not just this article, but many of their other newsletters as they talked about the HP500, 500EFI, and 525EFI on many occasions.
Crane Article on Marine Camshafts
Tech Tip

If you’re planning on trying to improve the performance of your boat this spring or if you have a customer just rebuilding his engine, check these few things first. When choosing a cam for a marine engine, the first thing you need to know is the type of exhaust that is being used.. There are several different types of marine exhaust systems which determine how big a camshaft you can use. If you have exhaust logs or underwater exhaust, you must use a cam with no overlap at .050? lift because of the back pressure created by the water in the exhaust system. If you have a through hull or above water exhaust system, you can choose a cam with up to 4 - 6 degrees of overlap at .050" lift. If you have double wall or water jacketed pipes that mix the water and exhaust at the end of the tailpipe, you can usually use any cam that would best match the compression and RPM that you want to prop the boat to at maximum speed. So make sure before you or your customer choose a camshaft, that you know what type of exhaust is in the boat. You don’t want to end up with water in your engine.
Here (again) are the three cams mentioned by the OP. Check out the .050" duration numbers this time.

Merc Mag Roller
Merc# 431-850478 / GM#12551622
.006" 288º/288º Overlap 57º
.050” 225º/225º Overlap -6º
Lift .483”/. 483”
ICL 109º
LSA 115.5º

Merc HP500 Carb
Crane Gen VI#169611 Grind#HR-284-2S-10IG
276º, 284º At .006” 60ºOverlap
222º, 230º At .050” 6ºOverlap
Lift with 1.7 .576” , .598”
ICL 105, ECL 115
LSA 110

Now, here : http://www.performanceboats.com/dyno/87614-big-thanks-chris-straub.html#post1425675
28Eliminator stated his cam specs as quote:

Looking up Bullet's Lobes that are as stated by 28Eliminator above in Bold + Red

we have the following:

Duration at .006" 284°, 300° Overlap 68° 8° More Overlap than HP500 at .006"
Duration at .050" 228°, 242° Overlap 11° 5° More Overlap than HP500 at .050"
.3823" Lobe Lift .3550" Lobe Lift
.6499" valve lift w/1.7 .6035" valve lift w/1.7
112° LSA
 

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Wrong lobes Scotty. The engine shows not sign of reversion. If had reversion the tops of the pistons would be clean along with the chambers. The engine dropped a seat and the water entered then.
I went by what was posted by the owner of the engine, 28Eliminator. See the link:
Now, here : http://www.performanceboats.com/dyno/87614-big-thanks-chris-straub.html#post1425675
and what I quoted above.

Where did he get that info from ?

If indeed incorrect, could you post the specs because I can only go by data that is given.

Thanks.
 

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Discussion Starter #6
This is a pretty far reach for anyone Scotty. No other cylinder shows signs of water. If it had reversion each cylinder would show signs. Water droplets just don't Choose a Cylinder to attack. You and the rest of your "I hate Straub Club" are showing what lengths you'll go to try and discredit me and it really makes you look like fools. For someone who wants the truth you sure are two faced when it comes to me. The engine ran flawlessly for 40 or so hours with no changes after it came off the dyno. It accelerated harder, had a new top speed and ran very well, then he tinkered with it. Dave told me on the phone he played with timing and changed carbs and jets in the carb. The engine dropped the seat and when it did the water got in there then.

Please don't turn Dave's bad luck into your own personal vendetta thread. It's poor taste.
 

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Discussion Starter #7

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The engine shows not sign of reversion. If had reversion the tops of the pistons would be clean along with the chambers. The engine dropped a seat and the water entered then.
Major reversion will maybe cause "cleaning" of the pistons etc. small amounts of reversion will mist with the A/F and you will still have combustion, which of course will not "clean" the pistons. Last time I looked, Rust in a cylinder is caused by water.
 

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Please post you suppliers information on where you get your stuff.. . .give me a break.
Woh, woh, woh. Hold on man.

You started this thread and you had some incorrect info.

Thread is about 28Eliminator and I used the camshaft specs he stated.

Edit to be more clear: your opening post is about duration/overlap/ reversion. I did not bring up the subject. edit done:

I have put correct data.

You say my data on his cam is wrong. Well, I got that from him.

So.............post the correct data.
 

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Discussion Starter #10
Major reversion will maybe cause "cleaning" of the pistons etc. small amounts of reversion will mist with the A/F and you will still have combustion, which of course will not "clean" the pistons. Last time I looked, Rust in a cylinder is caused by water.
Bill,
Steam cleaning doesn't take much water. Heat and pressure and small amount of water is all it takes to make steam.

Again the engine was trouble free for 40 some odd hours. All the pistons are black and show no sign of reversion.

How about Seat pressure slamming the valve and shattering the seat....is that for real. Do none of you know what a closing ramp is. There is another Crane article out there that has Crane testing more spring pressure on hyd rollers and the more the pressure the more stable the engine was. Higher spring pressure ensures the valve is set down on the seat.

Your neighbor up there Bill read that one and spit his coffee out.
 

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Discussion Starter #11
Woh, woh, woh. Hold on man.

You started this thread and you had some incorrect info.

Thread is about 28Eliminator and I used the camshaft specs he stated.

I have said nothing about his engine reverting. You have.

I have put correct data.

You say my data on his cam is wrong. Well, I got that from him.

So.............post the correct data.
Scotty,
Be truthful, we know why you are here.
 

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Is this NOT your thread starting post ????

Dave,
Sorry we had to talk on such bad news. I ran some numbers on the seat duration to see what overlap numbers looked liked as we did take in account on this build that you wanted a sound build that could use the short risers.

Mercury Mag 502 engine with cast iron manifolds has 57 degrees of overlap
HP500 Carb Engine and the shorts has 68 degrees of overlap
28Eliminators cam has 59.5 degrees

I called a ex Crane guy that was at Crane during the 90's and asked him about 60 degrees overlap and injesting water. He said 60 is no issue.
 

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Discussion Starter #14
Scott Birmingham or CFM Tech.....whatever you want to be called.
 

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How about Seat pressure slamming the valve and shattering the seat....is that for real. Do none of you know what a closing ramp is. There is another Crane article out there that has Crane testing more spring pressure on hyd rollers and the more the pressure the more stable the engine was. Higher spring pressure ensures the valve is set down on the seat.
Where did I post anything about this? My guess on the seats shattering is that the cold water caused them to shatter. As far as the spring pressure, on this motor with the owner requirements, its beyond overkill. All it does is beat up the valve train. The only time you need spring pressure this high is in high RPM motors, or with crazy high ramps that need it so the lifter will follow the cam.
 

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I followed all the threads on this

The piston in #7 hole, was hot in the hole period

The customer said the boat ran great when finished !!!

The heads and piston tell the true story of how the engine was running

For the life of me what the hell does the camshaft have to do with this ?

I have never bought a cam from Chris, but I would have no problem recommending him or buying one for myself.

Lets look at the reason for a hot hole and fix that before it happens again,

Big Steve
 

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Discussion Starter #17
I followed all the threads on this

The piston in #7 hole, was hot in the hole period

The customer said the boat ran great when finished !!!

The heads and piston tell the true story of how the engine was running

For the life of me what the hell does the camshaft have to do with this ?

I have never bought a cam from Chris, but I would have no problem recommending him or buying one for myself.

Lets look at the reason for a hot hole and fix that before it happens again,

Big Steve
Steve,
That is not the point here Steve. This crew sits and waits till one of my customers has issues then they create "there story" that always lays the blame on my camshaft. I don't care if its a faulty carb or a cracked header....its the straub cam that caused the failure.


Anyway. Yes Dave and I have spoke and I have told him anything I can do to help just call. A fallen seat is just plain bad luck.
 

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Discussion Starter #18
Where did I post anything about this? My guess on the seats shattering is that the cold water caused them to shatter. As far as the spring pressure, on this motor with the owner requirements, its beyond overkill. All it does is beat up the valve train. The only time you need spring pressure this high is in high RPM motors, or with crazy high ramps that need it so the lifter will follow the cam.
Again Bill you are not fully informed. Morel has been producing hyd rollers since about '01 when I got the first set to give to a customer to use. So after about 11 years of using, testing, and selling these to engine builders and customers I think I have a pretty good handle on it.
 

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Discussion Starter #19
I followed all the threads on this

The piston in #7 hole, was hot in the hole period

The customer said the boat ran great when finished !!!

The heads and piston tell the true story of how the engine was running

For the life of me what the hell does the camshaft have to do with this ?

I have never bought a cam from Chris, but I would have no problem recommending him or buying one for myself.

Lets look at the reason for a hot hole and fix that before it happens again,

Big Steve
The hot hole. 7 is a problem cylinder. Dave bumped timing up to 37 degrees and tried a carb and jet change. 7 got hot enough to burn the oil on the backside of the piston. Exhaust valve got rosey and was cupped. As it cupped it was pulled into the seat acting like a wedge. I use wedges when cutting trees. I speculate it finally cracked the seat and it was toast.

There is absolutely no signs of reversion and as Dave said the engine ran very strong.
 

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Where did I post anything about this? My guess on the seats shattering is that the cold water caused them to shatter. As far as the spring pressure, on this motor with the owner requirements, its beyond overkill. All it does is beat up the valve train. The only time you need spring pressure this high is in high RPM motors, or with crazy high ramps that need it so the lifter will follow the cam.
Tara, You haven't been banned yet?:(((((( Leave it to you to Fuckup a thread that has useful info...paging Info Paging Info...Time to clean house:stir:
 
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