TravisMcGill2000

iTrader: (2)

For some reason i got stupied on my build and put a stock timing set on my new motor. Has any1 ever broke a stock timing chian? Also should i pull my heads off and have everything checked out? What timing set should i go back with? Its a 94 with non vented opti.. Thanks guys

jaycenk

iTrader: (1)

I used the HD LT1 timing set http://www.summitracing.com/parts/NAL-12370835/
It uses a roller chain instead of the stock style chain

SpeedDensityZ

iTrader: (5)

I use to run a stock timing set on my 383. I never had any issues and the car made 446 on the dyno. I was probably just lucky though. I switched to a vented style opti just to run a double roller on my most recent build.

JasonShort

iTrader: (242)

I've always used the Cloyes double roller (must use an electric waterpump though). Part number 9-3145. If using an electric pump is not an option, the LT4 extreme duty is a good alternative, albeit a bit pricey.

You are just asking for problem with the stocker. Not only is it quite weak, but it ALWAYS has too much slack (even when new).

RamAir95TA

iTrader: (2)

I would also pull off the heads, just to make sure. No use in taking chances.

TravisMcGill2000

iTrader: (2)

I am using a ewp.. So the 9-3145 ill work on non wented opti's.. also should i pull my heads

RamAir95TA

iTrader: (2)

The 3145 won't work on non-vented spline-drive optis. You need a pin-driven setup.

TravisMcGill2000

iTrader: (2)

****... which 1 should i buy with the opti i go now

shbox

If you are using a non-vented opti, stock is about all you can use. The only aftermarket spline drive timing set I ever saw was from Doug Rippie Motorsports and it was extremely expensive. Not sure if it is even still available.

Puck

iTrader: (17)

Unless you are willing to part with a pretty decent chunk of change then you can really only go stock and cross your fingers. At your power levels you should have been fine, but **** breaks in racing, thats the name of the game...

I am switching to the EFI setup and running a 3145 cloyes(which I sold a brand new one for cheap thinking I couldn't use it before they released the TPIS timing cover )

TravisMcGill2000

iTrader: (2)

also i was goin bout 20 mph when this happen... Do yall think the pistons hit the down valves when it broke

GIZMO

iTrader: (8)

Your best bet is to pull the heads, inspect the tops of the pistons for signs of contact, and check that the valves are not bent.

robsquikz28

iTrader: (246)

anything can happen even at that low speed. They need to be checked, valves are thin and will bend easily.

shbox

It would be foolish not to check for valve/piston contact.

JasonShort

iTrader: (242)

Yeah, pull the head to inspect it to be sure. While you're in there, convert to a vented opti Then you can run the good chain/set!

Colin91Z

iTrader: (9)

I've heard time and time again people say that the stock timing sets are plenty strong for most builds. But reasons like this I don't believe it. This isn't the first time I've heard of a stocker breaking, I had one break back in 2005 on a 94 that had a hotcam/LT4springs combo. But that one broke at high rpm, and bent just about every valve in the engine. Also busted a BIG hole in the side of the timing cover.

My best advice to you is to pull your heads, inspect for damage, and like Jason said, convert to a vented opti and buy a good timing set.

Ever since my experience with this back in 2005, I run a billet cloyes hex-a-just in my own car. And I've had good luck using Progear timing sets a couple of H/C cars I've assembled.

macsz28

i just broke my timing chain and bent valves ... but i was going around 125-130 MPH... but id check yours just to be on the safe side.... i was running a double roller chain too...

Advanced Induction

iTrader: (2)

That is interesting. We have never had a customer report a stock timing set failure, and actually recommend them because of how reliable they've been with our setups. It would be worth the time to try and locate the root cause of the failure, be it bind, lack of p2v, etc. to keep this from happening in the future.

Anticipate requiring both replacement valves and head machine work. It is unfortunate, but it is an opportunity to do something w/ the head if you're so inclined. Good luck!

spcearle

iTrader: (9)

when i first had my 383 built i had a new lt4 chain break on me and bent a couple valves......mine was because of the waterpump gear.....i put in an electric wp and left the gear in the timing cover which eventually slid forward and rubbed into the chain...when i redid everything just took the gear out and put in dbl rollers.....so you may want to check the gear drive from the waterpump and if your running an ewp just remove it

DVS LT1

I went with the Cloyes "true roller" double roller timing chain for my 383 rebuild. I've got the exact part number at home somewhere. The kit cost like $80 or $90 bucks if I'm not mistaken (maybe less!). I had always planned to go with the Meziere electric water pump conversion so the double roller made sense.

Have any of you guys seen timing "kits" comp cams makes for LT1's??? The prices are freakin INSANE - like $500+ for timing sets. I don't care what they are made of, the costs are just outrageous. I think one of their selling points is that its a double roller chain engineering to work with/retain the cam driven water pump feature (I think). Otherwise who the hell would pay that much...

What does an "LT4 extreme duty" set go for? That's a few bills itself isn't it?

Anyone thinking of doing an electric water pump conversion should consider an old school (SBC) double roller setup.