4.3 Harmonic Balancer Question

[Bondo]

Re: 4.3 Harmonic Balancer Question

Granted,.... The Name "Vortec" was used before 1996,...........<br />The Technology of the Fast Burn Combustion Chamber,.. Known since 96, as Vortec,.......<br />Is This,.......<br />

<br /><br />Notice the Shape of the Chamber........ Your's Don't look like that......<br /><br />You can Sneak up on 10:1 compression with these,.....The "D" chambers start to Rattle around 9.5 or so.......

 

[Captianloud]

Re: 4.3 Harmonic Balancer Question

Yep mine are not like that, seams the heads have more volume, mine are supposed to be 68cc, those look deeper.<br />Well according to you then, I am flirting right with the edge of rattle (please define rattle). <br />Here's where I got my info.<br /> http://hotrod.com/techarticles/engine/113_0208_v6/

 

[Bondo]

Re: 4.3 Harmonic Balancer Question

(please define rattle).

The Engine Killer,.......<br /><br />Detonation.......<br /><br />I maybe Wrong here,.... But it Appears that you're getting Hung-Up on the Name,.. Vortec.....<br /><br />Look at the heads posted,....<br />The Combustion Chamber on Your Heads,....<br />Are a "D" shaped chamber,...... Correct,..??<br />And,.. I'm Guessing,... Probably 72cc or so....<br /><br />Now,...... Look at the 1s I posted,........<br />Can you See that they're a "Heart" Shaped chamber,..???<br /><br />It's the SHAPE of the chamber that Makes it a Vortec Head,.... Not the Volume.......<br /><br />Here's Your Head,...<br />

<br /><br />Now,..... Here's the Vortec Head,....<br />

<br /><br />See the difference in the SHAPE of the Combustion Chamber,..????...<br />That's What makes a Vortec Head,... A Vortec Head.......

 

[Captianloud]

Re: 4.3 Harmonic Balancer Question

Yeah, I got you dude, and I think I was pretty clear that I agreed the 1st pic you posted was not what I had.... Which one could logically deduce ment I am in agreement with you. I dont see the V name anywhere in the earlier post date 06 March 2006 7:43 pm, can you SEE that? Perhaps I should have used the word "those" instead of "the". Personally I am not hung up on anything so relax.....<br />According to the article Hot Rod magazine did..which I think for whatever reason they just might know thier stuff. They used an earlier head (see step 11) that for some reason looks real familiar to me. Although this version uses perimeter valve cover bolts-- they're talking 68cc....which is the volume I used to estimate compresion ratio <br />once again here is the link <br /> http://hotrod.com/techarticles/engine/113_0208_v6/ <br />So if you are correct at 72cc it moves me further away from preignition.<br /> <br />Rattle implies a loose mechanism. Where detonation, pinging, engine knock or preignition probably would have been more clear.......<br /><br />That being said.<br />My goal was to flirt with a higher comp ratio for the shear power & efficiency advantages of it while still being able to run cheap gas. I think I am safe enough from a danger point for several reasons.<br /><br />1) I can provide countless examples of ic engines approaching 10:1 comp ratio which run fine on cheap gas. Look at any modern sportbike.<br /><br />2) We are talking static compression ratio, the cam profile must be considered which is called dynamic compression ratio. This is the compression ratio the engine sees while running at a given RPM due to valve overlap, flowrate, intake charge temp & humidity and engine operating temperature and is ALWAYS a value less than the static value. While a cooler engine (typical to marine environemt), cooler intake charge with a relatively high water content (typical to a marine environment) are all condusive to supress preignition. The more radical the cam, the less the dynamic comp ratio, although this is a relatively mild cam, it's no where near stock. So for these combined reasons I think I'll be fine. <br /><br />3) And lastly, 4 barrel carb-you can almost always stop detonaion by a richer mixture condition; if it knocks, this carb allows jet changes without removal from the engine, so fattening it up should stop even a moderate preignition condtion. sure its not the ideal but it works...throw fuel at it, I see this as a last resort option only as it defeats mmileage/effeciency.<br /><br />I guess we'll have to wait and find out....<br /><br /><br />and yes I can distinguish between simple shapes like "d" and "heart" thank you.<br /><br /><br />I'm still not sold on the whole interanlly balanced vs. externally balanced deal with the flywheel. That too, I'll have to find out.

 

[Bondo]

Re: 4.3 Harmonic Balancer Question

Sorry,...........<br /><br />I guess you've already got it licked................

 

[Reel Poor]

Re: 4.3 Harmonic Balancer Question

Captainloud here is a little mor crankshaft information for ya. Just to help ya sleep at night. Here is what I found and here is where I found it. 90% V-6 crankshaft Info Its about 3/4's of the way down the page highlighted in orange. <br /><br />Somemore Crankshaft Information <br /><br />10224877p — Even-Fire Crankshaft (One–Piece Seal)This 3.48" stroke cast iron crankshaft is used in 1986 and later 4.3–liter V6/90°engines. It has a 3.00" diameter flywheel flange bolt pattern, and uses a one-piece rear main bearing seal. Technical Note: This crank requires a counterweighted flywheel for proper engine balance. <br /><br /> Sweet Dreams

 

[Captianloud]

Re: 4.3 Harmonic Balancer Question

Reel-Poor, <br />Excellent find, the GM tech publication, I got it in .pdf <br /> http://fbody.org.pl/wersja_stara/common/download/download/gmparts/p103-110.pdf <br /><br />Man-THIS IS the definitive info I was looking for with regards to the flywheel. Everyone I talked to and even the hotrod mag tech article explained it as same as a 350---an internally balanced engine. But when I saw the flywheel that came-out of the stock 4.3 engine I knew that something didnt seem right. Thanks for your insight and effort here. It is much appreciated. I am confident that this will work properly. <br /><br />Next hurdle is the differences in harmonic balancers. <br /> I am going to start the (auto) engine with the auto harmonic balancer. I turned .115" off the "face" of the perimeter ring in a lathe at work. I did this b/c the auto harmonic balancer interferred with the marine pulley set. The marine pulley now fits the auto harmonic balancer correctly. <br /> I am still real curious as to why the marine pulley has an offset weight to it?????? <br /><br />Unfortunatley I have no way run the engine with setting it into the hull. I did however use an old distributor modified so it has no cam gear and will accept a drill to prime the oil pump and oil system. <br /><br />I could really use a clear pic of the throttle linkage as this was removed by the previous owner, and the clymer doesnt show a good pic or diagram of it.<br /><br />Bondo, <br />Didn't mean to lash out at you there, but I thought we got to a point where we where beating a dead horse. Sorry... no hard feelings......

 

[Captianloud]

Re: 4.3 Harmonic Balancer Question

I meant<br />"Unfortunatley I have no way run the engine WITHOUT setting it into the hull. I plan to do that Sat morning. I did however use an old distributor modified so it has no cam gear and will accept a drill to prime the oil pump and oil system by turning the oil pump with the drill. I have already drained the fuel tank and replaced the fuel filter on the boat. The fuel pump runs fine as it is what I used to drain the tank. I will get some fresh gas for the install, and I have made all the nessacery preparations in the boat to help make for an easy instll.

 

[Reel Poor]

Re: 4.3 Harmonic Balancer Question

If the flywheels are interchangeable so are the balancers. Difference here would be in apperance only. Different balancers being made for different applications of installation. Some differences; ie. being made to fit different pullies for different drive belt set ups, having to make the belts clear other accessories or bracketry. <br /><br />Glad I was able to help. Be sure to let us know how it works out.

 

[Captianloud]

Re: 4.3 Harmonic Balancer Question

Nope, (remember I spotted the counterweighted flywheel and knew something was up) The balancers are CLEARLY not the same with respect to balance. One (auto) is "balanced" i.e. it is uniform.<br />The other is clearly counterwieghted, and by quite a bit. Look at the pics above, the marine one has a spoke at about 4:30 which is at least 3x the thickness of the other 2 spokes ( I know its hard to see). Where the automotive one was clearly "balanced". I could get a rough idea that the auto one was real close to balanced when I turned it in the lathe. (you can tell by how it cuts) <br />I dont know why this is. Its a 'ell of a question.<br /> I know the Z and W code engines (in automive) call for the same harmonic balancer. <br /><br />This I cant explain. Yet....<br /><br />The good news:<br /><br />I have both and plan to experiment with both to see what happens. I'll be sure to write about it on my website...<br /><br />Do you need a '75 ED? May need liver work....priced to move.