Need Some Dyno test results for 496
 

Just looking for Mercuiser 496 and or Volvo Penta 496 or both - STOCK real engine dyno numbers. I would like to have the MAG and the HO MAG if all possible. Also has anyone ever test hp at the propshaft for these other than the OEM. Thanks.

And if you have anything after the fact for numbers that the 496 was modified however and with whatever.

Some good info here John: http://www.offshoreonly.com/forums/g...h-busting.html

Ditto, might also contact Tyler Crockett. He posted 496 dyno numbers years back.

I am pretty sure Bob had a decent corretion factor. His tests were always spot on and he has answered questions for me several times (and was right). I know Tyler is a renowned engine builder but I am curious as to his correction factor on his 496 builds that I have seen. They are usually good. But, better than several others including Raylar themselves which creates some questions.... The same build with the same cam, and the same heads generating 40 more HP has to make a guy say hmmm.

We did dyno a stock 496 mag made around 385

I've got a 2003 496 MAG sitting at Retter Engine Development that should be dyno'd in the next week or two. It is now .030 over with forged pistons and h-beam rods but otherwise is totally stock. I can ask Ryan (Precision) for a photo of the dyno numbers to post.

I looked at a 496 - 35' fountain that had forged pistons, custom cam, head work, pushrods, etc. Arizona Speed intake and 85mm throttle body. It was $12k (2 engines) worth of work NOT including the Arizona intakes and TBs.

They put down 578HP and 607 TQ. 150 hrs later (when I drove the boat) the oil pressure gauges were blinking red because the oil pressure at idle was extremely low. Boat ran 83 mph I think.

I've dyno'd quite a few at the crank and the prop. If you are looking for the actual runs I can dig some up and scan them. I've done several Mags at the prop. They ranged from 365 to 375 using standard correction factor. The HO's ranged from 390 to a little over 400. I've done a couple of before and after's on CMI installs and a mag to HO with whipple tune. Also have Raylar upgrades and a few Whipple supercharger builds. What are you specifically looking for?

That website no longer exists since I have closed the business and retired. I do still have all
the information.

Thanks, I just wanted stock 496 MAG and HO MAG dyno pull numbers especially at the crank and if all possible at the prop. Also wanted equipment info what use used to obtain those those dyno numbers.

Thanks for the replies and who can provide this.

Also stock numbers first and possible moded numbers afterwards would work to.

What are you up to?

Most of this data is out there I have most of my max HP numbers memorized for my HO, HO with head mods and Raylar HO 600. What do you need?

Rage, Bandit and SD Fever have a bunch of modified dyno data. LOL Rage even has AF numbers for each cylinder. SD Fever has heavily modified Raylar stuff and Vortech Bandit has a ton of stock manifold highly modified data.

I am up to no good just kidding. I will let the info out down the road. I am working with 2 other people on something. Sorry I can not say any more at this timeframe.

I can say this for now, I am trying to work on being a problem solver for the marine 496. Just last year I worked on the earlier 496 cam sensors that are no longer available. I had 2 different sensors made for those apps but only 10 produced for now, (actually 11). Those damn things were expensive to get 11 made for testing. If I had 1000 cam sensors made, the price drops hugely but heck I did not want to get stuck with that many at this timeframe. I want to try these in the GM truck apps as well but I do not have the out for that end.

This new project has nothing to do with the cam sensor but I did come up with something else I very found interesting. 2 things that will be holding me back on this, is time and money as usual.

Really just need the stock pulls and equipment used that obtained those dyno numbers. Oh forgot to mention this, was the stock OEM 496 marine exhaust used for the dyno pulls ? Thanks and sorry about the vague posting.

FYI, my dyno is a Land n Sea prop shaft dual rotor, capable of holding 800 ft. lbs. of torque at the prop, .with dynomite pro software and electronic weather station. I have the hardware to use the brake on a stand mounted engine. So, I have the ability to dyno an engine at the prop and at the flywheel using the exact same dyno. I use the J607 standard correction factor, which as you know is 2-3% higher than what Merc uses. Altitude is 800' and being in central Texas it is always hot and humid. My corrections usually run 2-4% during winter and 10% or more durning the summer months. I have the capability to show raw HP and HP corrected to whatever standard you want in the software. I also test all engines in complete trim with wet exhaust on the engine stand, so the only difference in flywheel and prop numbers is drive loss. Hope this answers your question about equipment.

The HO I dyno'd in the article made 395 at the prop and 431 at the flywheel. I even moved all of the exhaust system from the boat to the dyno to make sure nothing changed.

Another project was a stock 496 Mag that I upgraded. It made 375 at the prop stock. We installed an HO cam, Whipple stage 2 ecu flash, 160 thermostat and Dana exhaust. It made 430 after the mods The boat picked up a solid 4 mph in before/after testing.

Hmmm, sounds familiar. Except I picked up a little more than 4mph and without the Dana exhaust... I'm assuming that was a single.

I would post the article but I don't have privilege to do so since I'm too poor to buy a membership now that I'm retired. I can email it to anyone that wants to see it.

Yeh, you have twice the engines....

Bob would you mind emailing me the article? I'm very interested in all 496 information. I would like to upgrade mine one day.

Thanks
John
[email protected]

Thanks and Thanks Bob.. I know the feeling so well for Texas boating - being 100 % in the boat biz and then having the lake level situation for the past 6 years really was not a biz to be in. Then last year most lakes closed because of flooding in the DFW area.

Anyways my email to send any info.

[email protected]

Please put a title on all emails. Thank you. John

I do know the Land & Sea dynos as well

If you developed a CPS for a '02 - '03 496 I'm a buyer. I had my builder discuss swapping over to the '04 - '07 timing gear, timing cover, and CPS with Raylar since his site claims it will work without PCM mods. Well, Larry tells my builder it is not a foolproof solution and the PCM sometimes wigs out with the conversion. I don't need my engine wigging out on me.

I am not sure the Dana did anything while stock. But I extended them to the transom then they helped. They definitely helped the Raylar 600.

Early on I did the CNC ported iron heads and they produced some power but later imploded a piston.

You really need to talk to Bandit. If for nothing else, he has done TONS of dyno testing on Merc 496 and the Volvo labled 496. Knows his stuff and is making a ton of power with the stock intake. Maybe even more then aftermarket intakes.

I have the 496 - 2001 and the 2002 / 2003 made - It goes by GM block codes to which sensor is used and it has to be a stock app for the reluctor on the gear thru those years and the crank and its reluctor needs to be stock as well.

I would be willing to come to whomever to do further testing with it and for the 496. And at no cost to the end user.

Last year every stinking 496 I seen and worked on was a 2006 and above. That would figure. Mine own personal 496 Merc is a 2008 as well. Those cam sensors are still available.

Please let me know who has what and we can test these so I can decide to have move volume made. I can come to you anywhere in the USA timeframes would have to be discussed. Thanks

Have to run now any other questions I will look for later on tonight. Thanks again. I am telling you straight up is very wise if you own the early 496 to have a least 2 extra cam sensors. If you need the reasons why, I will tell you and the hardship that you will have to go thru to make work correctly if you do not have these early cam sensor. It is a PITA and a costly one without the correct cam sensors.

So you have the sensors they are just not verified/proven yet? My 496 MAG, manufactured 9/03, serial number OM683216 is bone stock with the exception of the pistons and rods. I don't have the block code. I can't speak for Retter as far as their willingness to set aside time for CPS testing while my engine is being dyno'd. I can ask. I believe I'm slated for the dyno sometime in the next couple weeks.

^^^^ Yes I had these made as from 2 known good cam sensors per app and 2 known BAD cam sensors that were studied.

I posted up here last year about this and anyone who would let me test them on my time and my own dime. I had no responses. With that said I bet this would have taken place if they had a bad cam sensor, The end user surely would be ringing my phone off the wall and paying me for fixing their problem alot cheaper than what is called thru Mercruiser new parts buying and new installs costing min of 2 K especially if the engine has to be pulled.

I would think the same would hold true for the engine builders - trying to find the exact problem and then trying to find their solution to that problem if they had an cam sensor issue, then finding out it is NLA Just saying. It also might be to his benefit as well if in fact he deals with alot of early GM 496 marine and auto engines. Just saying. I have all the scan tools to see how well this plays out.

Thanks

My Advantage is a 2003, so I would imagine my two 496s are late 02, early 03 models. I had Bob change out the cam and had Dustin flash the ECM a couple years ago, but other than that they are bone stock.

Mine are 2003's how soon can I get two?

Where is the block code located?

BUP, are you saying that the O1's are the problem to get or the 02-03's or both? Just to be clear are you saying that the 04 and up are still available?

Edited: I forgot I looked into this to a while back. Sorry.

'04 and up is a still available part. You can find some '01's on eBay. There are also some '02-'03's marketed on eBay. Be careful. I ordered one last year only to find out the older GM part number cross referenced to an '01 sensor. So that won't work for my engine. So now I don't trust any of these eBay sources claiming to have these NLA sensors that have older part numbers. I wanted to take care of this issue while my '03 engine is out of the boat getting a rebuild due to a bent rod (reversion). However, changing over to the '04-up gear, cover, sensor, and pigtail as suggested on Raylar's site was discouraged by Larry at Raylar. Makes sense, huh?!

It goes by GM block code on the bottom side of the block or Mercruiser engine serial number per which cam sensor gets installed. The reluctor on the cam gear was changed about 4 different times thru out the whole 496 timeframe (existence) The first 2 cam sensors are NLA.

Long story I will post this info down the road. I probably was one of the first back some years ago to discover about the cam sensor NLA for the marine side as the available cam sensor was totally wrong for the earlier apps.

Anyways I have no idea what GM or EBAY has to offer for mercruiser. Volvo went a different route. What I did years ago was a search thru Merc as to what dealers had cam sensors left sitting on their shelves but DID NOT tell them the reason why. These cam sensor were Merc part numbers not GM or anyone else. I bought as many I could at that time frame. So last year I was down to just 2 cam sensors so I decided to have them made again I only had 11 made and have no testing time with them. Another reason I had such a small number made was I wanted to test them before anything else.

I can careless what EBAY has because alot of marine ignition and marine electrical products are china junk copies even junk copied fuel injectors that either do not work or fail in sort order or do not perform like they should. I can not tell you how times I have seen bad ign modules or ign sensors or fuel injectors with bad spray patterns that the end user has bought off ebay.

Like I said I took 2 new KNOWN good cam sensors and tested them from Merc packages and sent them off along with 2 used KNOWN bad cam sensors.

It would be 100% very wise that I get test time from whoever and where ever before I just send them to you. I would never just assume that we are good to go without testing these plus I like to keep my name good out in the marine market place.

I can show up with them and scanner in hand. The problem is, have not had any early 496 in my hands since these were made. That would figure - just the way it goes.

I don't mean to get this thread off track but I will pursue the cam sensor question since I believe the OP is interested. If we need to take this to another thread then lets do so. I have been documenting this on another forum but since there appears to be interest here we go. I may be generating more questions than I have answers for at this time.

I have a very early 2001 496 Mag engine (SN: 0M061519) with a STAMPED block code of 4XW. According to the block code this is a 2005+ engine. I therefore question whether or not the block code (note that this is different than the casting code) is a valid way to determine what engine you may have even though the parts fiche says look it up that way. Another (remote) possibility is that someone prior to my ownership put a new engine in it. If so, they transferred the serial number tag.

Model GM Code Comments
496 Mag XW 2001–UP 1XW Start 496 cid, GM MPI intake
496 Mag WW 2004 Changed intake manifold gasket and cylinderhead machining
496 Mag ZW 2004 Changed piston pins to floating type
496 Mag XW 2005–UP Returned to XW nomenclature
496 Mag HO XA 2001–UP 1XW Start 496 cid, GM MPI intake
496 Mag HO WA 2004 Changed intake manifold gasket and cylinderhead machining
496 Mag HO ZA 2004 Changed piston pins to floating type
496 Mag HO XA 2005–UP Returned to XA nomenclature

I have been intrigued by the cam sensor question since I do not believe that Mercury makes its own cam sensors or front covers or cranks or whatever. I assume that this is all GM stuff. If so then there will be an automotive equivalent. GM is not going to not supply parts to a 2001, 2 or 3 engine. Having said that I am attempting to verify this through the use of an automotive part but will not comment much further since the engine is currently out of the boat and it will be a month or so before I reinstall it and can run it. I do believe that there is an exact replacement part available. If you want to try it before I do look at a Standard PC948.

Comparing the Standard PC948 sensor to the original the standard is slightly SHORTER than the original. This means that 1) there will not be any interference with rotating assembly in the engine so you are not going to hurt anything by trying it and 2) it may not work as the gap between the sensor and the magnet may be too great to generate a reliable signal. We will know the answer when I try to fire it back up.

Looking at the new sensor carefully there are small tabs around the base of the sensor and on the mounting bolt hole. If these are removed (they are about 0.035 inches proud of the base surface) then the new sensor will only be about 0.010 shorter than the original. I am wondering if these tabs or posts are designed to be filed off for use in an early engine? Again, time will tell.

It seems like we are all in the situation that we cannot get a definitive answer since we don't have a complete range of parts in front of us to look at and compare. With us all working together we should be able to definitively address this issue. Again, my experience is limited to a sample of one engine. I am not trying to pass myself off as an expert or professional or anything other than an interested enthusiast.

No problems with me about posting whatever on the 496. will get back to you later

2001's: http://teamequip.com/gm-12572656-cam...a-kodiak-8-1l/

2002-2003: http://teamequip.com/gm-0314-1257067...ensors-t30163/

Disclaimer: This is me doing deep online searches. I do not know the company above and I'm not 100% positive those are correct for the years I posted.

Please double check and especially call them before just buying thru an online cart.

Do your homework

Was this Mercury's HO cam? If so, where did you source it? I may be interested in the same type of project.

SB I believe a copy from Mexico not even packaged as I am 99 % about these. I already seen these and I tried thru a customer of mine fall of 2014 who bought off of Amazon, - That boat owner told me it was a Texas company who gets its hands on truckload parts with some funky story behind it.

Just another reason I had them made - and yes a company in the USA made mine. I would watch out using unproven and not tested marine parts because even a wrong or bad cam sensor can cause water reversion and or no start conditions, even heavy backfiring. I do not like that risk and once again another online company that just sells whatever they get hands on. Just saying

Just adding this for a prime example buying unproven parts online. read pages 3 thru 5

http://www.offshoreonly.com/forums/d...n-issue-3.html

FYI. Even though I have an engine manufactured 9/03 and looking up the CPS on mercruiserparts.com by my serial number shows it taking the NLA '02-'03 sensor, my engine builder confirmed yesterday I have the '04 - up timing cover and sensor. So if you have a late date '03 engine don't assume you are screwed.