Another wtf...

[Mars]

Is the double roller going to be avail before spring? If so, I would take one. Hell I'd even pre-pay.

If not, I think I'll go with the pre '99 set...

[Superdave]

well, i got the front head taken apart and checked everything for damage, all the valves are mint.

I did find out something interresting though... I had to try out my new feeler gauge so i decided to check the piston pop-up. Contrary to whats been posted in this forum it is actually .020".


So yah, .025" between the piston and head.. It's amazing worse things didn't happen.

Yet another lesson learned, never trust anything you read on the internet. Always verify measurements yourself.

[El_Diablo]

i plan to use my old 3100 pulley on my 3500 since im selling my UDP now aswell, should already have a 1~" underdrive compared to the 3500's setup, just wonder if the water pump for the 3500 is different, same with the alt... hmm, either way im planning to atleast use the 3500 a/c compressor and most likely the pump since its almost brand new

minimum clearance i ever ran when i used to build engines down at the machine shop was .050", im not suprised at all that you had contact if you figure in rod stretch and the rpm's you were turning, i would say you got off pretty lucky, truely a testimate to how good the 3500 valves are aswell, both lightweight and you can use them to cut pistons!!

[PCGUY112887]

The alt is different, just swap an older one on with only 1 of the brackets. Make the bolts tight, it works fine.

For compressor I have no idea if that will work, seems like it would but the 3500 compressor is much different than the 3400.

3500 waterpump is just in the timing cover like it was before, just reuse it with it's pulley.

[El_Diablo]

i know the alt's are.... im planning to use mine

i can actually take pix of the a/c compressors side by side if you want... they aren't all that much different, just bolt locations, i have both, waiting to sell my 3100 a/c comp. from my malibu and picked up the new one from an 05 malibu with 44k miles IIRC

i know about the pump aswell, again, the question here is did they change the pump design or pulley size since the 3500 crank pulley should overdrive everything since its larger than the 3100 and 3400 pullies

[IsaacHayes]

Yeah I was wondering that too.

[Superdave]

water pump pully is the same.

[El_Diablo]

guess we'll see when i pull my water pumps as to if the impellers are different

[blackbombshell95]

How does a UDP affect the timing chain?

[Superdave]

How does a UDP affect the timing chain?

In theory since there isn't a harmonic dampener on the crank pully anymore that leaves the timing chain and belt system to absorb any harmonics. I've also heard the same thing about gear drives.. they transfer the combustion harmonics to the camshaft which supposedly can cause problems. I ran one for 5 years in my T/A on a roller cam w/o problems.


People speculate about this all the time but there are TONS of underdrive pullies out there on FWD engines and i've yet to come across an engine failure due to them. I'm still looking for some kind of dampener that we can bolt to the inside dish of the FFP pully, also got some other ideas in mind that could help.

[blackbombshell95]

Thanks for the reply. I've got a MRZ pulley which will be installed this week on my new build and now i'm contemplating on not installing it.

[1988GTU]

I heard that UDP cause eye irritations and cancer.


I'll leave mine on for another 4+? years.

[IsaacHayes]

Who knows how much if any is caused by the lack of the dampener. Unless someone wants to test it out and spend time/money who knows. Probably stock motors are affected less by any harmonics than say a highly cammed motor or one putting down tons more power due to say forced induction..

[treeZ24]

i know i've posted this before but have alook at ATI performance dampers. they are sfi rated as well.

expensive but well worth the money if you want an underdrive/lighter damper.

[3400-95-Modified]

I'm going to have my motor out of my car sometime in the next month or so, and I'll be inspecting my cam chain too. I've been running a Milzy cam with the LS6 springs, the chain had 4k on it when I got it, and I've put about 10k on this motor so far this year daily driving it... so I'll be interested to see how it looks.