Specifically on the 3.4.... Did you align the dots, or did you just slide the gears off and oput them back the same way they came off? Reason I'm asking is, Earlier when I changed my chain, I don't remember if I aligned the marks or not....I'm an idiot.

 

yea, aligning the dots does tend to play in your favor.

 

yep

 

It is absolutly mandatory for the dots to have been lined up.
IF ya moved the "set positioning" of those dots on the gears your engine will NOT run when you have put it back together.
I'd figure this detail out right now.
It really is this important a detail.

 

basically what i was getting at, just stated a little sarcastically.

 

If the engine was running when it broke, I would do a more detail check of everything before running the motor again.

 

Yep both times I alighend the dots.

Third time, its sitting in garage with dots alighned. Just waiting on cashflow to buy parts

 

the V6 uses the same timing chain as the V8 right?

 

no

 

what V6 is it that uses the same one as the SBC then?

 

Are you thinking of the 4.3 V6 which is a 350 V8 minus 2 cylinders?
There is "no" performance 60* Timing chain
It's to your advantage to find lowest priced T Chain item (with all steel new gears) & just install proper. Add balancer snout repair sleeve ($4) & ya set for no leaks!
Check levelness of the upper to lower gear before ya cover up.

 

cloyes makes a roller chain that allows it to be set at 2deg advance or retarted. Cost is about a bill.

 

The marks weren't aligned when the chain was removed, BUT, neither shaft was moved (crank or cam). Seeing how the gears only go on one way..... As long as timing hasn't jumped, aligning the marks only count when something is moved or is not right. At least that's what my boss says....He's built a fair amount of motors in his day (been in the biz for over 20 years). I did mine without aligning the marks, timing is dead on (as far as valve lift and TDC are concerned anyway...). Next time I suppose I'll align the marks. Maybe the results will vary, but I wouldn't advise it (must pay better attention).

 

Yes the marks should be lined up, you may of gotten lucky and just advance it a little? I don't know how many degrees a tooth makes up on the cam. But the marks should be line up unless you got a degree wheel and know what your doing.

I think you just got lucky and the gods of karma have smiled down on you. I would not try to repeat it though.

A fight between a piston and a valve is always a messy one.

 

The marks are only there for reference. If the chain hasn't jumped time, aligning the marks isn't necessary (but again, I wouldn't advise it). If the crank doesn't move and the cam doesn't move, replacing the chain is an off and on procedure. Remember, the gears only go on one way.

 

The gear going on only one way has nothing to do with it. The only reason they go on one way is to "pin" them in place.

Think about it for a sec, I'm not being a smart as here.

Doesn't matter if the cam or crank hasn't / had moved, if the chain stretched, you could be a tooth off. [Get me?]
The chain is what controls how they stay aligned. Stretched worn chain means the gear are not in perfect alignment. Why a car will run funny and lose spark timing.

And yep most times its a take off and put back on scenario but
cam to crank timing is more important than anything in your engine. Them marks are not there as a suggestion.

But I will just assume your timing marks were "aligned" in different positions and your chain was not worn. The marks don't always line up as they rotate around at different rates.

When you replace a worn stretched cam you should align the marks if you want a proper cam to crank timing. The car runs so who cares. Could it run better? maybe.

 

I never aligned the dots. I had the chain off twice and both times I just pulled the chain off and made sure nothing moved.

If you suspect that the chain has streched or jumped, then it'd be in your best interests to line up the dots.

 

it hadn't stretched very much (very little loosenesss). It hadnt jumped time. I would advise people to do it properly. It's just that I didn't... .

 

if nothing moved and it was running when you started the r&r it should be ok, but it's a gamble not knowing and not matching the dots before you remove the chain and gears.

 

http://www.jegs.com/cgi-bin/ncommerc...40&prmenbr=361
220-9-3137 Chrvy V6 2.8L, 1980-91 $93.99

Nice typo, but I'm pretty convinced they mean our v6.

Just thought I'd point this out since I remembered seeing *one* performance timing chain for our cars.. to my knowledge there are no others. What's the difference between 80-91 and 92+? No roller for the 3.1/3.4?

 

They are idiots, the chain will fit 2.8/3.1/3.4.

 

Glad to hear it

 

When I purchased the balancer snout sleeve for my 3.4 mills, I asked for a 3.4 repair sleeve for the balancer.
No response.
Asked for that part for the 2.8 engine, brought home the part.
90%-95% of 2.8/3.1 parts will work properly on the 3.4 conversion. Yet I certainly would specifically ask for 3.4 cylinder head gaskets or 3.4 replacement pistons.

What I "meant" by performance timing chain is, how much actual horsepower will you gain by advancing or retarding the timing chain for our aged or a freshly rebuilt 60* V6 engines?
Try the same "advancing & retarding" the timing chain trick on a V8 engine & you'll actually gain horsepower.

Would I invest/spend a $100 for this "Cloyes chain" for my 3.4 conversions?
No.
Others may, but I see no favorable return on investment, when I can spend about $30 on a new timing chain with steel gears and get same performance gain.

Yet, GM has designed the new "World Class" 60* V6 mills (debuting in the 2005 vehicles) with lots of tricks and I do bet that varible engine timing is one of those tricks.

I'd like to add that with the saved money of buying a $30 T Chain part verses the $100 Cloyes chain option, I would spend that saved $70 money toward final purchase cost of 1.6 roller tip rockers or true roller rockers for our 60* engines.
Purchasing & installing roller tip rockers or roller rocker of 1.6 ratio would definetly help up your horsepower, especially after installing a new timing chain.