Ok so I'm a little confused. The SBC in my 36 has a small diameter points distributor. I want to switch to electronic buy can't go with a GM HEI as there just isn't room for a larger distributor. I have a new GM 290 HP crate engine and they require a distributor with a "melonized" distributor drive gear. What would be a good distributor ? I looked at all the offerings from places like Summit and just got more confused. I suppose I could modify my firewall when the engine is out for a larger diameter distributor and run an HEI but my car is a finished driver and I don't want to go that route unless I have to. Any distributor ideas or suggestions ?
You could send yours to GMC Bubba (a Hamber) and have him rebuild and convert it to electronic and then set the curve on it or there are conversion kits that are popular.
I'd second having the stock on converted. It's a nice upgrade, and also keeps the nice clean look of the stock distributor. I do have a simple question though, whats wrong with just running the point set up? I'm NOT being sarcastic, just wondering. I've done both, converted to electronic, and stayed stock. Neither have even left me stranded and work fine. Can't help the gear though, first i've heard of that. Sorry. Tony
Me too actually but in the GM requirements for the warranty on the engine it says : Note: Distributor with melonized steel gear MUST be used with long-blocks and Partial engines with steel camshafts, or engine damage will occur.
The gear will replace the old gear. If you don't use it the cam will eat the distributor gear and vice versa, kinda like running a bronze distributor gear on most roller cams. You can buy one at you're local Chevy dealership, and I'll bet Summit and Jegs have them too. Larry T
put a pertronix in mine with the correct coil, same issue in my highboy room wise....piece of cake and looks stock
On my 40 Ford with the SBC ... I bought a small body HEI from MSD. It looked stock but had all the good stuff inside and even used a external coil. You can even use a stock looking distributor cap ... if you want. Mine had the melonized gear on the bottom. But it is 279 dollars ... http://www.summitracing.com/parts/MSD-8360/?rtype=10
I'd go with the pertronix set up. it very simple, and If you look at summit's website you probly find that gear. they have alot if stuff thats not in the catalog.
Info stolen from another post, (Lareger Dave on camaros net) Im not that smart. Melonizing doesn't harden the part were by the whole part is uniformly harder as in tempering, it is a chemical reaction involving Nitrate salts. Back in the early seventies GM used to nitrate their forged steel crank shafts using a vacuum deposit technology that took days to build up a couple of microns thick coating. The trouble is its is only a couple of molecules thick. The melonizing acts like a Teflon coating increasing wear by being slippery not increasing the hardness of the product (which technically it is so saying softer was a poor choice of words). The way to harden a part to make a wearing surface is to induction harden it with a high frequency transformer. This yields a thick hard machineable surface with a soft untempered core as is found in the ****er C-clip style axles. Since it is so thin you can literally see the underlying metal, so you can not see that part that has been melonized visually. Since it is only a couple of molecules thick the Brinell test will not work either as any attempt to scratch or abrade it would damage the surface. From what I've read on the web site they have greatly enhanced the technology of how they deposit the nitrate salts with some kind of hot metal spray and quenching. If you have ever gotten Mercury into a gold ring you know how they do it. It is like a soldering process were by one metal (or metallic salt in this case) is melted at a temperature well below the melting point of the base metal and allowed to flow into the base metal (there is a chemical term for this process that escapes me). Once inside the metal it is uniformly heated and quenched to distribute the metallic salt and temper the part so that it doesn't otherwise effect it's metallurgical properties. At least that is how I interpret it. I also have not mentioned this before now as it is also controversial and I prefer to help by clarifying issues rather than muddying the waters with my own opinions. But I take the melonized gears off of my distributors if and when they come with them, and throw them away. I then replace them with an "Old School" br*** gear that I know is the same hardness from the outside to the inside; and isn't relying upon a "crunchy candy shell" to keep a part from melting inside my motor.
After all the people getting sick off of cantaloupe, I don't want anything melonized. Sorry Lippy, now thats funny right dere.......
You can used the points to trigger MSD box and if it fails you can disconnect the box.This is also works.http://www.davessmallbodyheis.com/
From gm performance parts... <TABLE border=0 cellSpacing=0 cellPadding=0 width="100%"><TBODY><TR><TD>[FONT=arial,helvetica][SIZE=-1]10456413 - Distributor Gear[/SIZE][/FONT] </TD><TD vAlign=bottom align=middle></TD><TD></TD><TD vAlign=bottom align=middle></TD></TR></TBODY></TABLE><!-- end ItemDroplet --><!-- ***le: product display (for product detail pages) --><!-- display the product --> <TABLE width="100%"><TBODY><TR><TD vAlign=top>[FONT=arial,][/FONT] [FONT=arial,] [/FONT] </TD></TR><TR><TD><!-- long description -->[FONT=arial,helvetica][SIZE=-1]This melonized steel gear is required on all crate engines and roller camshafts that are made of steel. If engines are ***embled not using this gear it may affect your engine warranty. [/SIZE][/FONT]</TD></TR><!-- A Switch is used for Technical Notes. If the Technical Notes (footer) is either blank or 'unset', no text will be printed. If the Technical Notes are populated, they will be displayed on the screen. In addition, the default text 'No Technical Note Available' was left, just as another 'failsafe'. --><TR><TD colSpan=5>[FONT=arial,helvetica][SIZE=-1]Technical Notes: Components in these groups are interchangeable with small-block Chevrolet V8s. GM Performance Parts distributors cannot be used with "tall deck" Bow Tie block P/N 14044808. This gear is part of distributor ***embly P/N 1104067. [/SIZE][/FONT]</TD></TR></TBODY></TABLE>
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