3.9 Timing chain and gears--- changing for performance stuff?

[SLC99Disco]

Hey guys I am in the process of rebuilding a 3.9 for my Classic and I was just wondering if it would be worth it to purchase a performance timing chain and gear kit instead of just a replacement kit?

I am going to used timing chain and gears made for the Buick 231 V-6 (straight swap from my understanding) and I have found some kits have a 3 keyed crankshaft gear that will allow me to retard or advance the timing by 4 degrees. My thought here is to retard the timing 4 degrees to get a little extra top end power out of the 3.9.

What are the engine guru's thoughts on this?

Here is a pic of the Edelbrock kit, part # 7828

 

[SLC99Disco]

And here is a shot of the regular style, you can see the single key slot on the crank gear

 

[MUSKYMAN]

I think you are asking for trouble...the lucas system is picky enough.

you dont want top end power in a 4x4 anyways...keep it simple

put in a crower cam and a cheap timing set and be done with it, the stock timing sets were plastic toothed crap so even a cheap timing set will be a upgrade

 

[SLC99Disco]

I think you are asking for trouble...the lucas system is picky enough.

you dont want top end power in a 4x4 anyways...keep it simple

put in a crower cam and a cheap timing set and be done with it, the stock timing sets were plastic toothed crap so even a cheap timing set will be a upgrade

Thats kinda what I was thinking, I started looking at the timing set just to replace the plastic toothed stuff, but then started thinking it might be fun to play with an semi-adjustable set up

 

[lwg]

I did this with a cam on a 3.9L. I think I ended up advancing the timing 4*, which ever gives more low end torque. Honestly couldn't tell a difference. I even added some Headers and a 4.2L Fuel map chip...

 

[sven]

I used that edelbrock TC on my 4.2 RRC. But I didnt ef with the cam timing, I left it at TDC.

 

[ptschram]

I'm a fan of doing things simply, especially if one is not ABSOLUTELY certain of what they are doing.

Time it the way the book shows, but use the best parts you can. The steel replacement set that D&D sells is a great timing set, the double roller set is overkill for most engines. My 4.2 is being built with the double roller set, but I have some $ to blow (first time in a LONG time) and I want to do it once.

The steel set from D&D is even less expensive than stock and better too!

 

[BFox]

I thought the Buick parts that swap over are from the 215 V8, not the 231 V6.

 

[SLC99Disco]

I thought the Buick parts that swap over are from the 215 V8, not the 231 V6.

Almost positive that its the same engine minus 2 cylinders, the 231 parts I am gonna use are from the odd fire v-6

 

[lwg]

Almost positive that its the same engine minus 2 cylinders, the 231 parts I am gonna use are from the odd fire v-6

The timing chain I used was for the Buick 215 V8. It's possibly the same as your 231...

 

[robertf]

probably the same as a bruick 350 too

A friend of mine advanced his crower 230 cam on his 4.2 whatever the minimum is and it sucked. It ran noticeably better in the stock config.

 

[SLC99Disco]

The timing chain I used was for the Buick 215 V8. It's possibly the same as your 231...

I am pretty sure the 231 and 215 use the same timing components

 

[SLC99Disco]

probably the same as a bruick 350 too

A friend of mine advanced his crower 230 cam on his 4.2 whatever the minimum is and it sucked. It ran noticeably better in the stock config.

I am confused? Did it suck or did it run better?

 

[sven]

I am pretty sure the 231 and 215 use the same timing components

FWIW, 231 even fire and odd fire are different.

 

[SLC99Disco]

FWIW, 231 even fire and odd fire are different.

Yes, thats correct, I meant 231 odd fire engine parts sorry for the confusion

 

[benlittle]

So the 215 chain kit do swap over to a 3.9 with no mod?

 

[peter sherman]

yes

http://store.summitracing.com/partdetail.asp?part=CLO-C-3003K&autoview=sku

 

[benlittle]

Thanks Peter. I found a kit at Napa, $30