Has anyone installed a whipple supercharger on a 496?
06-21-2012, 07:59 AM
#21
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A guy on my dock had a couple of whipples installed on his 496's. He literally blew up three times and lost a season and a half due to downtime before he gave up on the idea. If you have money to burn maybe you get lucky and it holds up for a while - but as others have said the 496's were not made with internals designed to hold up under supercharging. I'll bet the people who make a living selling the kits will say different - see if they stand behind the final product (entire engine) with a warranty. That should tell you all you need to know.
06-21-2012, 12:05 PM
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I guess if you consider and accept that my experience, knowledge and information of the 496 (8.1L) engine is pretty well founded and established you will read and understand the following:
1. Whipple makes excellent products and superchargers. Their kits and products are some of the best researched, developed and manufactured supercharger products in the world and Dustins knowledge, experience and successes with superchargers is without equal.
2. There have been some stock Merc 496's both Mag and HO that have been converted with Whipples supercharger kit and are still running just fine after 100-300 hours but there have been more that put on a nice 496 kit and after in some cases in very short hours grenaded.
Was this caused by the supercharger, NO, it was caused usually from piston or rod failure, blown head gaskets, or from poor installations, poor tunes and set-ups.
3. The only differences between all Merc 496 Mags and HO's came in 2000-early 2001 when GM produced and shipped a few 8.1L base engines to Merc that had a 5140 forged crankshaft made by Kellog. From that point forward ALL 496's (8.1L) engine have the same pressure rolled fillet cast crankshafts (very strong) not your grandad's old cast crankshaft, a weaker forged big block rod (very small section modulus above the rod journal area) that break, a hypereutectic cast piston that was designed for emmissions and has a short distance between the top ring land and the top of the piston.
The only difference between any 496 engine or 8.1L engine produced after mid 2001 is the camshaft MAG versus HO and the tune in the ECM.
Laugher here is Merc always sold the engines for $4k to $5K more for a camshaft and ecm program that their cost difference was zip -zero difference!
4. The stock 496 (8.1L) engines DO NOT fare well generally with supercharging-Why? because the higher boost pressures (higher compression ratios) stress the piston and rod strength. The higher cylinder temperatures under boost in the stock iron cylinder head tend to put the engine close to or in detonation a lot of the time and the effects of detonation on the stock hypereutectic piston are usually catistrophic. Most of the time a 1-2" piece of piston top near the valve relief breaks away and if it lodges in the quench area of the chamber, the piston comes back up to TDC, strikes the piece of broken piston and hammers the piston to death in a hundred or so pieces. If the rod breaks under load, it snaps off just above the rod journal end and commences to wedge against the rotating counterweights of the crank and usually gets pushed out through the side of the block!
Now this can happen on a stock 496 unmolested engine, it can happen on a Raylar equipped higher horsepower kit engine and its not as often as supercharging but it does happen.
Usually this happens when the fuel system acts up and lean burns the engine under loads, the engine is severly overheated or with oil system malfunctions or problems.
5. Is the 496 (8.1L) engine a big problem with failures, no. when you consider there are over 50,000 out there in boats and you hear of 100 or so have issues after 10 years of use and service thats not a problem, except for that owner. There have been probably less than 3-5% total 496 failures over the 10 years and the only 496's you generally hear about are the ones talked about over the internet. Back when the 454MPI's-502MPI's where released and used in smaller quantities you did not hear as much about failures because the internet in those days, the discussion forums and such DID NOT EXIST and I am sure if one studies the numbers from then and now you will most likely see the 496 has been less failure prone and problematic then the 454-502 series engines.
6. Can a 496 (8.1L) be MORE reliably supercharged? YES, It just should be done with supercharger strength forged pistons, a stronger H-beam rod, a good set of MLS head gaskets and good head bolts or studs and a really good re-tune on the ECM matched to the charactersitics of the supercharger and injectors with safe air fuel ratios and good injector control.
7. Can you make equivalent horsepower with a longer life normally aspirated 496, YES, it just takes a base engine built with good forged HD parts, good heads and camshaft and coupled with a good exahust, proper ECM retuning many see 625-650HP with such a build.
8. Can a stock block 496 make 525-570HP reliably normally aspirated, YES, hundreds have done so or are doing so with the Raylar BCK103 engine kits , exhaust upgrades and some with other builds and specs. from some other performance marine engine builders. These can run for 750+ hours with proper use, service and maintenance.
9. IN MY PROFESSIONAL OPINION, Should you put any supercharger system on a stock 496 (8.1L) engine ?, ONLY IF YOU LIKE 10-20% ODDS.
IS IT THE SUPERCHARGERS FAULT -NO !
Hope this information and opinions are informative and of assistance and I hope the facts here teach you sometimes to not believe everything you read in those Magazines and here on the internet!
Best Regards,
Ray @ Raylar
1. Whipple makes excellent products and superchargers. Their kits and products are some of the best researched, developed and manufactured supercharger products in the world and Dustins knowledge, experience and successes with superchargers is without equal.
2. There have been some stock Merc 496's both Mag and HO that have been converted with Whipples supercharger kit and are still running just fine after 100-300 hours but there have been more that put on a nice 496 kit and after in some cases in very short hours grenaded.
Was this caused by the supercharger, NO, it was caused usually from piston or rod failure, blown head gaskets, or from poor installations, poor tunes and set-ups.
3. The only differences between all Merc 496 Mags and HO's came in 2000-early 2001 when GM produced and shipped a few 8.1L base engines to Merc that had a 5140 forged crankshaft made by Kellog. From that point forward ALL 496's (8.1L) engine have the same pressure rolled fillet cast crankshafts (very strong) not your grandad's old cast crankshaft, a weaker forged big block rod (very small section modulus above the rod journal area) that break, a hypereutectic cast piston that was designed for emmissions and has a short distance between the top ring land and the top of the piston.
The only difference between any 496 engine or 8.1L engine produced after mid 2001 is the camshaft MAG versus HO and the tune in the ECM.
Laugher here is Merc always sold the engines for $4k to $5K more for a camshaft and ecm program that their cost difference was zip -zero difference!
4. The stock 496 (8.1L) engines DO NOT fare well generally with supercharging-Why? because the higher boost pressures (higher compression ratios) stress the piston and rod strength. The higher cylinder temperatures under boost in the stock iron cylinder head tend to put the engine close to or in detonation a lot of the time and the effects of detonation on the stock hypereutectic piston are usually catistrophic. Most of the time a 1-2" piece of piston top near the valve relief breaks away and if it lodges in the quench area of the chamber, the piston comes back up to TDC, strikes the piece of broken piston and hammers the piston to death in a hundred or so pieces. If the rod breaks under load, it snaps off just above the rod journal end and commences to wedge against the rotating counterweights of the crank and usually gets pushed out through the side of the block!
Now this can happen on a stock 496 unmolested engine, it can happen on a Raylar equipped higher horsepower kit engine and its not as often as supercharging but it does happen.
Usually this happens when the fuel system acts up and lean burns the engine under loads, the engine is severly overheated or with oil system malfunctions or problems.
5. Is the 496 (8.1L) engine a big problem with failures, no. when you consider there are over 50,000 out there in boats and you hear of 100 or so have issues after 10 years of use and service thats not a problem, except for that owner. There have been probably less than 3-5% total 496 failures over the 10 years and the only 496's you generally hear about are the ones talked about over the internet. Back when the 454MPI's-502MPI's where released and used in smaller quantities you did not hear as much about failures because the internet in those days, the discussion forums and such DID NOT EXIST and I am sure if one studies the numbers from then and now you will most likely see the 496 has been less failure prone and problematic then the 454-502 series engines.
6. Can a 496 (8.1L) be MORE reliably supercharged? YES, It just should be done with supercharger strength forged pistons, a stronger H-beam rod, a good set of MLS head gaskets and good head bolts or studs and a really good re-tune on the ECM matched to the charactersitics of the supercharger and injectors with safe air fuel ratios and good injector control.
7. Can you make equivalent horsepower with a longer life normally aspirated 496, YES, it just takes a base engine built with good forged HD parts, good heads and camshaft and coupled with a good exahust, proper ECM retuning many see 625-650HP with such a build.
8. Can a stock block 496 make 525-570HP reliably normally aspirated, YES, hundreds have done so or are doing so with the Raylar BCK103 engine kits , exhaust upgrades and some with other builds and specs. from some other performance marine engine builders. These can run for 750+ hours with proper use, service and maintenance.
9. IN MY PROFESSIONAL OPINION, Should you put any supercharger system on a stock 496 (8.1L) engine ?, ONLY IF YOU LIKE 10-20% ODDS.
IS IT THE SUPERCHARGERS FAULT -NO !
Hope this information and opinions are informative and of assistance and I hope the facts here teach you sometimes to not believe everything you read in those Magazines and here on the internet!
Best Regards,
Ray @ Raylar
Last edited by Raylar; 06-21-2012 at 12:11 PM.
06-21-2012, 08:23 PM
#23
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A guy on my dock had a couple of whipples installed on his 496's. He literally blew up three times and lost a season and a half due to downtime before he gave up on the idea. If you have money to burn maybe you get lucky and it holds up for a while - but as others have said the 496's were not made with internals designed to hold up under supercharging. I'll bet the people who make a living selling the kits will say different - see if they stand behind the final product (entire engine) with a warranty. That should tell you all you need to know.
06-21-2012, 08:27 PM
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That don't make sense. You do realize the only difference between a Mag and HO are the cam and flash right? I recently had my two Mags converted to HOs, and for the most part it was a no brainer. Same internals in both motors. I have heard stories of 496s grenading after a whipple was installed, and other stories about folks getting 400-500 hours of worry free service with one. I have always been told, in order to "safely" mount a whipple on a 496, at the minimum, pistons and crank should be upgraded. I didn't have the $10K per motor it would take to "properly" install the whipple, so I went cheap and made mine HOs.
The mag camshaft is not a good cam, as its cylinder pressure at low rpms is very, very high and the only way the SC lives on them is very little timing and 4psi of boost in a boat. The HO's can take 6psi of boost with very little issues as the cam is bigger and has more overlap. The difference is all of 60+hp when boosted.
06-21-2012, 08:34 PM
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from what I have read the 496 ho with supercharger can live a long time But you have to baby the motor . In other word's No wide open throttle for any amount of time ." ok maybe one minute or 2 and that's it .
I think if you run the boat at mid range to pick up a better cruise speed they work fine but if your going to be Jo racer and jump wave's and do whole shot's they won't hold up as long
mike
I think if you run the boat at mid range to pick up a better cruise speed they work fine but if your going to be Jo racer and jump wave's and do whole shot's they won't hold up as long
mike
But as for babying, I don't really think this is true. Every failsafe is built into the calibration, temps, knock, etc. and if you run too hard, oil temp will go up, or water temp, etc. so you'll get a warning and reduced power. The system has made some big changes in the last year, all standard with the larger 3.3L SC, new bigger throttle body, all new calibration with significant changes, etc.
06-25-2012, 09:37 PM
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running a 25P mirage+ for break-in (+30 wiseco blower pistons,eagle rods),going to use 27P mirage+ or 28P bravo1 later,as the 25 is VERY easy to spin with this set-up...also have an IMCO hyd. steering,single cyl. that we'll be installing soon (xr drive)
01-02-2013, 06:22 PM
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Any less than 3psi is basically a waste, but with 4-5psi, thats very much possible and obviously more conservative. Just needs .25" bigger SC pulley and everything else is identical.
