When i first fired my motor it ran pretty good..the valves werent adjusted but i could tell it had good compresison...Id give it a quick little stab on the gas and id hear this massive "spark ping" ...now it wasnt a clap from the rockers,this ping would only happen underload...i drove it around the court i live on to verify this and it pinged like a MF'er...i looked up info and the spark table for the LT1 and LT4 motors to see when all the spark is in by...STOCK these motors run 33 degrees total with 8 degress base and its all in by 2,800....the MSD distributor comes with the slow springs (total is all in by like 4,200) and the 21 degree advade stopper installed....i changed the springs to the Light siler one and a light blue one...(2 light silvers are faster then 2 blues) so this way it would all be in by 2,800 or so..i installed the distributor in EXACLTY te same spot as when i took it out...motor fired right up and i reved it like i did before and the POS still did it..although it didnt sound the same...it sounds more like a mechanical grinding noise...so i then lashed the valves, got the 1/4 turn still made the noise, although wasnt as bad and the motor rumbled a lot more as i went down the bank..
i read up some more and it turns out the the LT1 motors like 1 full turn after lash, some even more..I went out and lashed them one full turn and the motor really got a mean rumble to it..it didnt choke out or start shooting it all out the pipes or anything, it sounded really healthy...once i got them all done i reved like before and it still made the noise but it was alot quiter then before i started with the valves...
when i was doing them only the number 1 intake and 4 intake pushrods were shooting oil out of them, then rest were like a dribble..this was at idle..could one of my lifters or 2 of my lifters be collasped?...

Thanks guys

Rob

 

no oil shooting out of the rocker isn't a problem. i can't think of any reason why a lt1 engine would "like" more valve lash more than any other SBC. you might want to increase the octane of the fuel or change the timing a little

 

i was surprised when i heard it to..i have a book http://www.cartalkers.com/store-item...locale-us.html and in it it states that after lash go one full turn...rather then doing it right away i went to camaroz28.com and asked around there...a few guys responded when they changed there cams from stock they backed off the nut one full turn before they started clapping...If they were set that tight from the factory then thats good enough for me...

im using 93-94 octane in it and before all this crap i had the base set to were it ran the smoothest..and it ran very smooth and was quite responsive, untill i loaded it then it pinged/grinded...thats when i tightend the valves up and most if it went away..

 

Valve lash is dependant on lifter design, not the engine they're in.

If you're not using stock lifters then contact the manufacturer for specs.

 

the lifters are stock..were there any changes to the lifters from 91 to 93....from what ive read and reasearched they are the same...thats why i reused them, i couldnt justify 250 bucks for a set of lifters when they were in perfect condition and with a stock cam...

the springs were installed when i bought the heads..they are pioneer .525 max lift...i think the closed pressure is around 200 pounds and open is close to 300 IIRC...ill ask the guy tonite...

usually when u got more then a half turn the valves wont seat fully and the motor will start misssing....but the more lash i gave this motor the healthier it sounded...

 

yall not know or not care

 

i thought yall were smart

i guess i should take it to a "professional" eh?.....

 

I dunno, if you do take it to a Pro, I hope you give him a little more info on what's under the hood.

For starters, all I can tell is you have a MSD mech advance distributor, so I'd guess you are running a carb'ed engine?

I also know your heads have springs that can handle .525 lift.

I've also gleened that you "put the distributor exactly" back in. Means you need to recheck base/initial.

What I don't know is ..
Engine (and history)
\Heads
Head volume
CR
Cam
Basetiming (verify)
Full advance (again, verify don't guess at the rate or total by paper specs).

I also don't know if you're wondering what the grinding noise is, or the ping.

Ofcourse a Professional will know all the above by the decals on the bumper...but you didn't even attach a pic of the car

 

the motor is a 94 LT1 shortblock with LT4 heads and a 650 DP
the compression ration with 4 cc valve reliefes will be 10.5 +-.1
the cam is a stock 94 peice...201/447..208/459
as far as base timing read my other post "seperate timing issue"
i havent figured out how to "mesh" a gen 1 balance/timing tab to a LT1 motor with the opti block off (theres noonwere to mount the timing tab, so i cant verify base timing..i had it running were it ran the smoothest..for LT1's there base is 8 degrees..STOCK
when iu installed the distributor (MSD Vacuum advance pt# 8361)
it was with the slow springs installed..i read up on the LT1 spark tables and they like 33 total and its all in by 2,800....so i adjusted the srpings accordingly..and the pingin did get less., but it also kinda changed (the noise)...then it sounded like a grinding noise, so i lashed the vaves on the off chance the the pushrods were coming out of the lifters...i went 1/4 turn and it got better but was still there, looked up the lashing specs and from the factoory they take 1 full turn..so i went a full turn and it went away further, it also didnt hiss the charge out the cylinders from them being to tight, it sounded healthier the more i gave it!....

i cant verify the base timing because of the timing tab issue im tryin to figure out, so set it to were it ran the smoothest, but from how it ran and how crisp it was im gonna say im pretty damn close...
i really dont know what else to try...i know its has enough spark in it, as i adjusted the curve to the spark tables of a stock LT1....
i guess im tryin to get some opinions on whats going on...

if the distributor cant be a tooth off, (i still want to know why its not possible for this to happen) then its in or 180 out, 180 out it wouldnt run...so that leads me to beleive that the timing is pretty close..then the only thing i can think of is the grininding noise if coming from the rockers slapping the tip of the valves...it doesnt do it at idle and even if i bring the RPM's up linearly, it will only do it if i stab the gas hard and fast...and also when i start to take off (load).....

I REALLY APPRECIATE you replying mike!...somone does care it seems

 

Ok say it is a ping from the timing off and not nessesarily a "grinding" noise....

Im sitting here and i think about this...since theres play in the valvetrain, the valves arent opening/closing at the correct time. Now im not the smartest guy in the world , but to me that would look like the timing being off, and in the worst way...

are your ears smoking yet?

 

Lol...okay, here's where I'd start...

Pull the valve cover, watch the valves, get #1 as close as possible to TDC as you cane.

Find a good reference point on the block somewhere so you can view this "reference point" and the HB with a timing light . Mark it zero then get the appropriate timing tape for your size of HB.

You might be a few degrees off, depending on how well you found TDC. You could get more exact, but this should get you pretty close.

If you have all the valves set at 1 full turn past zero lash, you're fine. The factory does it this way (so do I) and since you're running a factory-sized cam and lifters (looks like anyway) you shuold be fine.

I don't think I'd rely on LT1/4 specs for base timing or curves and total, since it's all PCM controlled and EFI...start conservativly.

When you say "play in the valvetrain", do you mean slack in the timing chain?

Re dis off a tooth...yes it can be off one, two or ten teeth...(from where it orginally was) and you can compensate by rotating the distributor or moving the wires around...but don't just assume that since it starts up, and runs, the base timing is anywhere close to what it should be. You could be at 15-20* BTDC and it'll still fire up and run...so you could still have too much initial, adding too much total throughout the curve...that's why you need the timing tape to verfiy.

Ofcourse this assumes that there's no vacuum leaks, or you're not running it too lean, etc.

 

Ok when im finding TDC i make sure both the valves are closed on the top of the compression stroke...i have heard to carefully place a screwdriver into the spark plug hole and when the piston gets to the top, slowly rotate the motor till the piston just starts to fall theres TDC...im right on track to what your saying about the refrence point..thats a good idea BTW thanks...
Im gonna go back through the valves and redo them all again..just for peace of mind AGAIN...
For the curve ill start a little more conservative then i am now, but i dont want to go conservative on it, im running 93-94 octane and it does have Ten and a half to one compresison, so its gonna like an "Aggressive" curve...When i said play in the valvetrain i meant since the rockers were loose that the pushrod could thoeretically "come out" of the lifters, the lifters would flop around on the cam..and i think that would cause a lot of noise..
when i had it running i could retard and advance it probly an inch each way, and it defintely affected it,..i set it right in the middle...
does the location of the vaccum advance caniter have any meaning?

there arent any vacuum leaks and its actually a little on the rich side

thanks again bud!!
Rob

 

You guys have me completely confused. You have an LT1 and it has a distributor? What the heck?? Am I missing something?

Are you checking the balancer and aligning it to 0 after you bring the piston up? Just turn the motor until you feel air blow out of the cylinder then keep turning until the timing mark hits 0.

 

GM sells an intake manifold to run a standard carb and distrbuter on a LT1 motor.

 

.

 

"" havent figured out how to "mesh" a gen 1 balance/timing tab to a LT1 motor with the opti block off (theres noonwere to mount the timing tab, so i cant verify base timing..""

Was why I suggested what I did.

 

LOL, ive gotten that a few times when ive opend the hood for people...there like when they a big bowtie were the thermostat should be lol

tomorrow im gonna get a new timing tape and then use a dremmel or somthing to cut out a little chunk from the block, or i could get all fancy and make an arrow pointing toward the balancer .....it didnt really dawn on me that i wouldnt be able to mouth a timing tab till i was ready to fire it up, and honestly ive been trying to figure out how to mount the gen 1 tab ONTO the LT1 timing cover...then mike came up with this brillant idea lol...


88IROC350TPI.....What is your opinion on my problem im having with my valves and or timing?
now that your not hiding anymore

BTW, thats a tough looking iroc :hail:
Thanks guys
Rob

 

Well if you don't have a proper timing mark, putting the distributor in and setting it is near impossible. I'd be 90% sure thats your issue. Have you tried drastically retarding or advancing the timing?

I noticed you have an MSD distributor. Is it a small-cap Pro-Billet kind or an HEI? I hate dropping my Pro-Billet in... for some reason mines a huge PITA to ge right. I can literally get a stock HEI one in on the first try but my MSD never wants to drop in the proper spot for some reason. Do you have a hard time getting it to seat properly?

Once you get the motor to TDC like I said, drop the dist in with the rotor facing straight forward. Directly inbetween #1 and #8 (on the cap). Make sure the vacuum advance canister is not too close to the firewall and not too close to the intake - right in the middle. The 'standard' method is to point the rotor directly at #1 but the shape of the MSD cap kinda screws with ya since its more round compared to squarey-HEI caps.

I hope I make sense, its late, I'm tired.
-Chris

 

When it had it running i could go about an inch each way and it would nearly stall (both ways)...i have the PRO-Billet 8361...it uses the magnetic pickup off the 6AL rather then white wire, and yes it is a PITA to get it to slide in there, what i started doing is instaed of taking it out and adjsuting the oil pump shaft then putting it back in, id just bump the starter and it would seat all the way...your the first person to say anyhting about the canister...when i had it running the smooothest the canister was pointing (with the valve cover used as 6 o'clock) it was at 8...im tired to does that make any sense? lol


what do you think about the lifter issue?..

thanks again
Rob