questions on my fresh lt1
10-10-2007, 02:38 PM
#1
questions on my fresh lt1 Alright im new to the forum but just thought id see if any of you could help me out. I just built the lt1 out of my camaro its now a 355 and has:
speed pro coated hyper 10.5:1 2 valve relief pistons
Stock heads
hot cam kit w/ 1.6 rr
msd full billit opti, wires, and coil
the heads are shaved .010 and the block is decked .010
well now this is the least of my problems but im having issues getting oil pressure to the top, i have bad lifter noise no matter if i adjust them or not, so i took it back out tore it back down went threw it again this time putting a High volume oil pump in it, still having issues all my oil gally plugs are in and they are all clean. I just thought id ask about that.
The main thing i started this up with is i just got 80 miles on this 2nd go around and was going on a car cruise with the car club and broke the brand new timing chain
, any one ever have this happen? im scared to death that i bent some valves just looking for your guys' opinions. These are the pistons i used http://store.summitracing.com/partde...0&autoview=sku
speed pro coated hyper 10.5:1 2 valve relief pistons
Stock heads
hot cam kit w/ 1.6 rr
msd full billit opti, wires, and coil
the heads are shaved .010 and the block is decked .010
well now this is the least of my problems but im having issues getting oil pressure to the top, i have bad lifter noise no matter if i adjust them or not, so i took it back out tore it back down went threw it again this time putting a High volume oil pump in it, still having issues all my oil gally plugs are in and they are all clean. I just thought id ask about that.
The main thing i started this up with is i just got 80 miles on this 2nd go around and was going on a car cruise with the car club and broke the brand new timing chain
, any one ever have this happen? im scared to death that i bent some valves just looking for your guys' opinions. These are the pistons i used http://store.summitracing.com/partde...0&autoview=sku 
10-10-2007, 05:59 PM
#3
You do realize that most piston compression specs are for a 64cc chamber and you have a MUCH smaller chamber and compression is likely closer to 11.5 than 10.5, not a bad thing just something you need to know.
A broken timing chain on an LT1 is a freak occurance, the stock chains are quite stout.
On the oiling I think you missed a plug of some sort, I do not know where to tell you to look but hopefully someone like Ellis pops in and gives details here. You should not have needed a HV pump.
I would pull the heads, when the timing chain broke there pretty much had to be piston to valve contact somewhere.
A broken timing chain on an LT1 is a freak occurance, the stock chains are quite stout.
On the oiling I think you missed a plug of some sort, I do not know where to tell you to look but hopefully someone like Ellis pops in and gives details here. You should not have needed a HV pump.
I would pull the heads, when the timing chain broke there pretty much had to be piston to valve contact somewhere.
10-11-2007, 12:12 PM
#4
thanks for the reply, and i did know that about the champers its rated like 10.46:1 with 58cc chambers but i havent checked it since the heads are shaved and the blocks decked.
Im kickin myself because ive been through this engine twice this year, BUT i am using stock replacment fedral mogul lifters ive been thinking about going with comp lifters or so seeing if it would make a difference. Thanks for the reply, im going to go with the lt4 timing set, this whole thing sucks. Just wondering if anyone has ever broke one and had that type of failure.
thanks
Im kickin myself because ive been through this engine twice this year, BUT i am using stock replacment fedral mogul lifters ive been thinking about going with comp lifters or so seeing if it would make a difference. Thanks for the reply, im going to go with the lt4 timing set, this whole thing sucks. Just wondering if anyone has ever broke one and had that type of failure.
thanks
10-11-2007, 05:40 PM
#5
I have heard of more LT4 ED sets breaking than stock ones so I think your decision to go to the LT4 chain is at best a waste of money.
The stock LT1 chambers are a bit smaller than 58cc so your motor is more than 10.5, without running the math it should be in a good range for a mild NA LT1.
There are only a couple lifter builders, the Fedral Mogul are likely the same exact ones as stock and the same exact ones as the basic Comp, the Comp "R" performance lifters are trouble prone, basically I think you are chasing the wrong thing there.
The MSD opti is much more trouble prone than the stocker too.
The stock LT1 chambers are a bit smaller than 58cc so your motor is more than 10.5, without running the math it should be in a good range for a mild NA LT1.
There are only a couple lifter builders, the Fedral Mogul are likely the same exact ones as stock and the same exact ones as the basic Comp, the Comp "R" performance lifters are trouble prone, basically I think you are chasing the wrong thing there.
The MSD opti is much more trouble prone than the stocker too.
10-12-2007, 01:28 AM
#6
If you do replace the lifters, i recommend the gm ls7 ones, not because they're better but because they're only 100 bucks from any number of sponsors.
On the oil pressure issue, how is the oiling otherwise is it pretty low even with the hv pump? the first place i would look when you pull the motor is for the "check ball" under the rear main cap, its just a little pressed in ball under there, it blocks a passage that runs straight out the top of the block i believe to the oil pressure sending unit. Without it you will bypass the filter and never have satisfactory oil pressure. If that checks out, knock out all your galley plugs and remove your cam bearings which are likely toast, and scrub the **** out of the galleys with engine cleaning brushes to look for debris. When you reinstall the plugs have them tapped and put in threaded plugs, dont forget the holes on the lifter galley plugs behind the timing chain the two outboard ones at 3 and 9 should have a pinhole drilled in them to lube the chain.
imho you broke your timing chain for one of two reasons. one is that you didnt get your crank gear all the way on and it was binding, the other is that due to a lack of oiling the top of the motor or not putting the "**** holes" in the galleys the chain didnt get oiled enough and overheaded and snapped. The only oiling the chain will recieve is from drainback without the holes, i dont feel that its enough to do the job with the gear driven water pump. if you go to an elec water pump and a double roller by all means... skip the holes, i just always put them in every engine now out of habbit.
On the oil pressure issue, how is the oiling otherwise is it pretty low even with the hv pump? the first place i would look when you pull the motor is for the "check ball" under the rear main cap, its just a little pressed in ball under there, it blocks a passage that runs straight out the top of the block i believe to the oil pressure sending unit. Without it you will bypass the filter and never have satisfactory oil pressure. If that checks out, knock out all your galley plugs and remove your cam bearings which are likely toast, and scrub the **** out of the galleys with engine cleaning brushes to look for debris. When you reinstall the plugs have them tapped and put in threaded plugs, dont forget the holes on the lifter galley plugs behind the timing chain the two outboard ones at 3 and 9 should have a pinhole drilled in them to lube the chain.
imho you broke your timing chain for one of two reasons. one is that you didnt get your crank gear all the way on and it was binding, the other is that due to a lack of oiling the top of the motor or not putting the "**** holes" in the galleys the chain didnt get oiled enough and overheaded and snapped. The only oiling the chain will recieve is from drainback without the holes, i dont feel that its enough to do the job with the gear driven water pump. if you go to an elec water pump and a double roller by all means... skip the holes, i just always put them in every engine now out of habbit.
10-12-2007, 02:56 PM
#7
would you all agree that the ED lt4 timing chain is a waste of money? I do have oil pressure on my gage so i THINK the check ball is out of the question correct me if im wrong. If the LT4 chain is a waste please let me know so i can send it back to jegs and buy a cloyes stock replacement. Why is the msd trouble prone? thanks for the help keep the ideas coming really apreciate it!
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10-12-2007, 03:15 PM
#8
Rotor rubbing caps, rotors coming off, not really KNOWING what your timing is unless you put in a degreed damper, keyed hub and fabricate a pointer. A friend had one go haywire after a burnout he went back to stock.
As much as the stock opti is hated it has a better track record than the MSD if you look at the info atall objectively rather than the "it is aftermarket so it is better" bias most have and undoubtedly lead you to spend twice as much as necessary on a distributor.
The "features" of the MSD opti over just the cap and rotor are only useful to fairly advanced users, for most it is just more variable to misstrust. More than one guy has attacked it with a screwdriver to "fix" the timing because it seemed off. I helped one guy who overadjusted it ruining it, turned out two plug wires were crossed, found that after putting a stock opti back on.
People put too much blind faith in the aftermarket, consider the 36K+ mile warranties(70K emmissions in some states) and 100K mile target tuneup intervals GM was putting on these cars, they did a lot of things right to get them there.
As much as the stock opti is hated it has a better track record than the MSD if you look at the info atall objectively rather than the "it is aftermarket so it is better" bias most have and undoubtedly lead you to spend twice as much as necessary on a distributor.
The "features" of the MSD opti over just the cap and rotor are only useful to fairly advanced users, for most it is just more variable to misstrust. More than one guy has attacked it with a screwdriver to "fix" the timing because it seemed off. I helped one guy who overadjusted it ruining it, turned out two plug wires were crossed, found that after putting a stock opti back on.
People put too much blind faith in the aftermarket, consider the 36K+ mile warranties(70K emmissions in some states) and 100K mile target tuneup intervals GM was putting on these cars, they did a lot of things right to get them there.
10-13-2007, 12:58 PM
#9
You have never stated what your oil pressures are so I dont know if its acceptable or not, but you want at least 20 at hot idle in an lt1 and around 60-75 at higher rpms (using a white spring in oil pump).
The thing about the ball is you will have oil pressure but you wont have sufficient oil pressure, it looks to me like you just threw a hv oil pump at it instead of looking for the problem. If you broke your timing chain imo you need to take the motor out and apart anyways, so you tell me if its ruled out when you pull the rear main cap.
and yes the lt4 timing chain is a waste of money imo, i've beat the holy hell out of dozens of lt1 chains with huge spring pressures and solid roller cams and never had a bit of trouble with one.
The thing about the ball is you will have oil pressure but you wont have sufficient oil pressure, it looks to me like you just threw a hv oil pump at it instead of looking for the problem. If you broke your timing chain imo you need to take the motor out and apart anyways, so you tell me if its ruled out when you pull the rear main cap.
and yes the lt4 timing chain is a waste of money imo, i've beat the holy hell out of dozens of lt1 chains with huge spring pressures and solid roller cams and never had a bit of trouble with one.
10-14-2007, 05:07 PM
#10
Alright, to be honest i should have never said that the check ball is ruled out because i dont know what check ball your talking about, do you have any pics of it from when you put your engine together, is this somthing special to the lt1? because ive never noticed one on any of the engines ive put together, on the guage the oil pressure is about 20-25 at idle and around 60-70 at higher rpms. the second time i did look for the problem, i sent it back to the machine shop to to checked again worried that a galley may have been cracked, then when i got it back spent a lot of time cleaning it. I am really curious about this check ball so if you have anything to take pictures of or pictures of it please post them so i can see what im looking for!
I really appreciate the out put. lol this is starting to get old this is the 3rd time im gonna have to pull this thing out. but one of these times hopefully ill get it!
I really appreciate the out put. lol this is starting to get old this is the 3rd time im gonna have to pull this thing out. but one of these times hopefully ill get it!
10-14-2007, 05:29 PM
#11
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Yeah, not really gonna be able to get pictures. It's underneath i think the number 1 main cap??? U really aughta buy an lt1/4 rebuild book. It talks about it in there.
