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| bam | putting together my 355 LT1, questions | ||
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Senior Guru
 
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Picked up my block, crank & pistons from the machine shop today, will be putting it together myself over the next few days, weeks. A few questions; (93 LT1, 355, hot cam, Mahle pistons, recon. rods)
1. What head gasket(I know there is one that bumps the comp. ration up a tiny bit, is that the impala)? 2.Where can I find the oil pump drive that interfaces with the cam drive? Checked Rock Auto NA 3.I have added Trick Flow 185 heads, can I still get by with my FIC 24lb injectors? 4.When I prime the oil pump with the intake off how long can I wait before then putting the intake on and the motor in the car? (is it a problem if it is a week or two) 5.Any other advice is appreciated, things to remember to do while in there (it's been 15 yr since I last assembled a motor)? Thanks |
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Posted on: 2012/2/1 1:57
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| vetteoz | Re: putting together my 355 LT1, questions | ||
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4.When I prime the oil pump with the intake off how long can I wait before then putting the intake on and the motor in the car? (is it a problem if it is a week or two) Oil seems to hold in the block passages well. Just turned a LT1 that had been sitting for 3 months with no oil in it upside down on the engine stand , thinking it should be well drained and it dumped nearly a qt of oil out of the OP switch hole |
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Posted on: 2012/2/1 2:52
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| rklessdriver | Re: putting together my 355 LT1, questions | ||
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1. The Impala gasket or the Victor Reinz PN 5898. About $17 each.
2. I buy new ones from GM Parts direct or the dealer. It's PN 1103868 and cost about $45. 3. Every Hot Cam and heads build I have seen was fine on stock injectors. 4. Ideally you want to prime it and start it but with an LTX thats kind hard to do. Prime it and bolt the intake on it as close to installing the engine in the car as possible. A week or 2 will be fine as long as you prime it well. 5. Be smooth with pulling the TQ wrench. Double check everything. Do not use grease on the roller lifters or roller rockers because it can clog the small oil holes. Use a heavy assembly lube like Clevite Bearing Guard. Will |
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Posted on: 2012/2/1 18:36
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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| bam | Re: putting together my 355 LT1, questions | ||
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Will thanks a bunch!!
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Posted on: 2012/2/2 3:41
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| bam | Re: putting together my 355 LT1, questions | ||
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What about break in oil and filter? Change after about 30 min of running and then again at 100 mi? Brand, weight of oil?
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Posted on: 2012/2/2 14:26
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| rklessdriver | Re: putting together my 355 LT1, questions | ||
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Roller cams don't require any special oil for break in. Put what you intend to normally run in it.
I don't subscribe to the 30min thing. You can never be too careful but IMO that's a little extreme. However you will want to change the oil and filter within a couple of hundred miles of start up because the filter will get packed with assembly lube and the oil will be contaminated with it and very small amounts of metal from the rings and cyl wall. Get the car started and drive it for a few hundred miles to make sure the rings are seated, no rods are gonna fly out of it, ect.... And then change the oil and filter. Should be good to go for regular oil change intervals after that. Will |
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Posted on: 2012/2/2 18:11
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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| bogus | Re: putting together my 355 LT1, questions | ||
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Grand Imperial Pooh-Bah
 
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I honestly don't know your experience level, but this is advise for anyone:
LT1s have an oil fitting of some sort on the front of the engine... It is real important and I don't remember the details! I am only leaving it here as a tickler for more experienced LT1 builders. I don't have my LT1 book handy right now. Debur around the oil return holes in the valley. Every little bit helps with oil return. Clean up around the holes on the top of the deck surface. When you get the engine back, clean the bejeebus (tech term) out of it. Spray brake cleaner into every hole or port or whatever you can see, get everything out of that block and do it three times. Pour simple green into the cooling jackets and then follow with a hose. CLEAN CLEAN CLEAN! I use STP oil treatment as an assembly lube. Did some reading on the stuff... NAZI rocket scientists created it to protect engines in fighter planes, after the pans have been shot out. It essentially took old school oil and turned it into modern multi-viscosity detergent oil. From that perspective alone, I suspect its rather useless these days, but it does make a great assembly lube. I use it on bearing surfaces, cams, timing chain, and on the cylinder walls. It all but makes preoiling pointless. The upside to preoiling? You know the pump works.  |
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Posted on: 2012/2/3 3:26
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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| tjpreul | Re: putting together my 355 LT1, questions | ||
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Is this what you are thinking? Under the rear main cap there is a ball bearing (plug) that needs to be punched out for proper cleaning. You use a long punch from the oil pressure sensor port. It must be reinstalled otherwise it will bypass the filter. |
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Posted on: 2012/2/3 4:06
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| bogus | Re: putting together my 355 LT1, questions | ||
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I thought there was something in the front... inside the timing chain area. Damned my freaky memory.
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Posted on: 2012/2/3 7:32
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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| vetteoz | Re: putting together my 355 LT1, questions | ||
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delete
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Posted on: 2012/2/3 12:42
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| tjpreul | Re: putting together my 355 LT1, questions | ||
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There are three oil galley plugs behind the timing chain. The two outer ones have a small pinhole in them to help supply oil to the waterpump gear drive. This was an update according to some service manuals. My '92 had them. |
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Posted on: 2012/2/3 14:26
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| BillH | Re: putting together my 355 LT1, questions | ||
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Yea, some people go nutso with the "break in"/oil changes. |
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Posted on: 2012/2/3 14:34
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Every man dies but not every man lives. |
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| bogus | Re: putting together my 355 LT1, questions | ||
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YES! That's it! |
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Posted on: 2012/2/3 20:09
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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| EngineDoctor | Re: putting together my 355 LT1, questions | ||
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Yes clean, clean, clean !
Check all your clearances during assy , write them down for references, and make any necessary corrections.Take your time! |
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Posted on: 2012/2/3 22:30
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| bam | Re: putting together my 355 LT1, questions | ||
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The book "How to rebuild small block Chevy LT1/LT4 Engines" says about these plugs with the hole in the front; "these are an oddball size you may be forced to reuse them. Coat them with locking compound then apply a two part epoxy to assure a good seal" I just reused mine. I was wondering about head bolts, can I reuse them, is that wise or should I get new ones? As for the oil galley plugged by that ball in the back, I told the machinist to remove it and then clean the motor and then reinstall. Hopefully he did. I checked the mains with plastiguage and have 2 - 2 1/2 thou. on all. Still have to check the rod clearance. |
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Posted on: 2012/2/4 0:21
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| rklessdriver | Re: putting together my 355 LT1, questions | ||
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If your measuring .002-.0025 using plastigauge, it should be good.
Pull the rear main cap and MAKE SURE that plug is under there. If it's not you will burn the brgs out of it in no time. At some point GM went to TTY bolts and those should not be reused. I don't know when that change applies to the LTX. I always put ARP head bolts in the engines I build. You can tap the front of the block and use screw in NPT plugs. I did it on my 92 but on an LTX the outer holes are smaller than a normal SBC and that was about 3-4yrs ago so I don't remember what size plugs I used. I just scronged thru our extra stuff with a dial caliper and drill/thread chart until I found some plugs that would fit. Will |
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Posted on: 2012/2/4 17:09
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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| EngineDoctor | Re: putting together my 355 LT1, questions | ||
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Master Guru
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Hope this helps :
Just some very basic clearances that I would check IMHO 1) Mains .002 5/10 - .003 2/10 2) rods .001 8/10 - .002 4/10 3) rod side clear. .012 -.017 4)piston to wall Follow manufacturer specs. 5) ring end gaps .018- .021 (TOP & BOTT) 6) crank thrust .004-.006 7) piston to deck .005-.017 below deck Just safe numbers in my opinion...application may vary. Also I would pull all the oil plugs outa the block re-clean , then lock them back in place with lock tite. Attach file:  404528_2245955326988_1791312576_1522190_1179949592_n.jpg (33.22 KB) |
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Posted on: 2012/2/4 23:33
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| bam | Re: putting together my 355 LT1, questions | ||
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Ok, I got a Fel-Pro "impala" head gasket # 9966PT and I find it is not the thinner gasket but the .050 compressed thickness gasket. Everyone (local parts stores) cross references this FP gasket with the Victor Reinz and says it's the same but it's not. Where can I find the thinner gasket in the Victor Reinz? Need some help here, thanks.
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Posted on: 2012/2/8 3:06
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| tjpreul | Re: putting together my 355 LT1, questions | ||
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Here is one from Mr. Gasket that is .040 Mr. Gasket #720-3141G http://www.jegs.com/i/Mr-Gasket/720/3 ... 10002/-1?parentProductId= |
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Posted on: 2012/2/8 4:58
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| bam | Re: putting together my 355 LT1, questions | ||
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I figured out how to get the Victor Reinz 5898 Impala gasket, go to rock auto and search for the 1999 impala and it is listed there, $18 plus change, cost 32.89 each at the local parts store here.
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Posted on: 2012/2/9 19:27
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| tjpreul | Re: putting together my 355 LT1, questions | ||
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Are there any updates on your build?
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Posted on: 2012/7/24 14:53
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Vegas wasn't built on winners. '92 auto, MSD, Banski, Taylor wires, SS lines, C5 rims, 3.07 gears, white gauges, seats from a '96. Motor: Forged rotating assy, Probe pistons, CC valvetrain, AFR heads, Procharger P1SC |
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| bam | Re: putting together my 355 LT1, questions | ||
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Yes, thanks for asking. All back together and running, have driven it about 800 mi. The power improvement is really great. But I am having what I think is a tuning problem. From idle to 2000rpm it you are crusing the car jerks. It is especially bad in 1st thru 4th gears, still noticeable in 5th, not at all in 6th. Step on the gas even a little and it goes away or off the gas and it goes away, the jerking is very annoying at steady cruise below 2000rpm. I pulled the plugs and they are carboned up with a black soot that looks like it is running rich. My tuner has tried to tune this out, this is his 3rd try and not much better. At idle the lope of the cam sounds like something much bigger that a hot cam and the smell at the back end of the car is horrible and burns your eyes.
Something else I noticed is that when I remove the filler cap for the gas tank there is no whoosh of air coming out anymore. No pressure at all. Today I checked the charcoal canister valve back by the tank, it holds pressure and air can be blown thru it like the FSM says. Also when I first turn the key on the fuel pump runs for over a minute before it shuts off, used to run only a couple of seconds. Fuel pressure is 42 and holds steady after you shut the key off. Any thoughts appreeciated. |
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Posted on: 2012/7/24 22:20
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| BrianCunningham | Re: putting together my 355 LT1, questions | ||
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What's your idle set to?
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Posted on: 2012/7/24 22:45
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Polo Green 95 LT1 6-spd http://mysite.verizon.net/vzevcp74/ 383 LT1/Vortech Supercharger/AFR heads/Rod end suspension/Penske-Hardbar dual rate coilovers/Wilwood 6pot brakes NCCC Governor: http://BayStateCorvetteClub.com |
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| Matatk | Re: putting together my 355 LT1, questions | ||
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Did you change the torque converter at all? Have you done any datalogging?
I get some cam surge at low rpm in 4th gear but not 1 through 4 ...I'm a little stumped by that. Fuel pump shouldn't run for a minute with key on. I'm wondering if the relay is sticking or a wire got pinched during reinstall? Matthew |
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Posted on: 2012/7/24 23:09
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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| bam | Re: putting together my 355 LT1, questions | ||
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I can see it is set to 800 in the tune but it only idles at 650 according to the tac. |
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Posted on: 2012/7/25 1:45
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| bam | Re: putting together my 355 LT1, questions | ||
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It's a 6spd. yes I have data logged it 3 times, need to learn to read it?! Is the fuel pump initial run set by the computer? I think it is but don't know for sure. I can't seem to down load pix, would like to post some. I'll try again |
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Posted on: 2012/7/25 1:47
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| Matatk | Re: putting together my 355 LT1, questions | ||
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See if you can post up your datalogs here. I'm no expert by ANY means, but it might help.
The fuel pump primes for 2 seconds upon key on, I don't know where the parameters for that start from to be honest with you. I'll have to look in to that. |
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Posted on: 2012/7/25 3:41
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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| BrianCunningham | Re: putting together my 355 LT1, questions | ||
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that would be the 1st thing to look into I'd check the IAC out. |
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Posted on: 2012/7/25 21:37
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Polo Green 95 LT1 6-spd http://mysite.verizon.net/vzevcp74/ 383 LT1/Vortech Supercharger/AFR heads/Rod end suspension/Penske-Hardbar dual rate coilovers/Wilwood 6pot brakes NCCC Governor: http://BayStateCorvetteClub.com |
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| rklessdriver | Re: putting together my 355 LT1, questions | ||
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I'm not going to tell you tuner how to tune but....
Cam surge at low RPM with part throttle is probably a bit too much ignition/timing advance. The smell at idle is from the camshaft's overlap where both valves are open and raw fuel from the intake cycle is pulled out of the cyl and thru the exhaust valve before it closes completely.... essentially unburned fuel entering the exhaust system. He should be able to pull some injector pulse at idle to clean it up a bunch. Speed Density cars are tricky to get right at idle and it takes some time and talent as a tuner. Again excessively rough idle is too much ignition timing advance. The GM Hot Cam should only have a slight lope (if you could even call it that) at 800RPM.... at a true 600RPM it'd sound like it's got some RUMP, RUMP but I don't know for sure that one would idle down that low without stalling. Will |
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Posted on: 2012/7/25 23:50
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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| Matatk | Re: putting together my 355 LT1, questions | ||
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Is there a way to set base timing on optispark cars or is it all programmed?
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Posted on: 2012/7/26 1:59
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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| bam | Re: putting together my 355 LT1, questions | ||
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I believe it is all programmed, however I do have a MSD opti which has 5 deg. adjust-ability built in. I am trying to post pictures or my data log showing timing but can't. I'll try again soon. Thanks for the replys, I really want to get this solved. |
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Posted on: 2012/7/27 2:40
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| bam | Re: putting together my 355 LT1, questions | ||
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Here are some parts of the most recent data log. I guess I was trying to load to big a file, the timing looks pretty close? What do you think?
Attach file: IMG_4510.JPG (36.06 KB) IMG_4512.JPG (70.04 KB) IMG_4513.JPG (70.32 KB) |
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Posted on: 2012/7/27 3:06
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| bam | Re: putting together my 355 LT1, questions | ||
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Will, I bumped the compression up by using the Impala gasket. I believe that takes it from 10.4 stock to about 10.8 with my 355 ( 30 over bore). Would that require less timing than stock ratio or make no difference? Take a look at the tune and see what you think about the timing. I realize it's not from the data log but the tune. I am new to the data logging and am not sure how to post a data log, or even how to find it. I am using DataMaster to log with. Thanks |
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Posted on: 2012/7/27 3:13
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| rklessdriver | Re: putting together my 355 LT1, questions | ||
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That little bump in compression won't make much difference at idle. The cam overlap is whats doing everything.
Considering that a well tuned Hot Cam LT4 should idle in the 40-45Kpa range @800RPM I personally think he needs to drop about 3-4* of advance in that range to smooth the idle out... BUT there is still the problem of over fueling at idle which when fixed may totally negate the need to screw with the timing table. Honestly, I'm not the guy to talk to about the specifics of tuning. Engine building and machining, I'm more than competent on.... With tuning I'm just knowledgeable enough to get my self in trouble and I've always got Ed to bail me out (for a fee).... Will |
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Posted on: 2012/7/27 14:41
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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| bam | Re: putting together my 355 LT1, questions | ||
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I notice I am running 14" of vacuum at idle, seems kinda low for a hot cam, was thinking it should be around 16. Anybody out there running the hot cam and checked vacuum at idle, is 14 normal?
Will, do you mean Ed from PCM's for less? |
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Posted on: 2012/7/27 16:23
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| rklessdriver | Re: putting together my 355 LT1, questions | ||
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No, the guy that tunes my car is Ed Hutchings (edcmat-l1 over on CF).
14" of vacuum at idle is about 55 Kpa on the MAP.... so your not that far off. Will |
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Posted on: 2012/7/27 17:47
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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| EngineDoctor | Re: putting together my 355 LT1, questions | ||
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Beware of fuel wash, most damaging thing to your engine.
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Posted on: 2012/7/27 19:06
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| Matatk | Re: putting together my 355 LT1, questions | ||
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Also, compression is a factor of what pistons you used and heads/ head work. Do you have any knock counts?
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Posted on: 2012/7/28 0:04
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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| bam | Re: putting together my 355 LT1, questions | ||
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Quote:
I am looking at my last data log and at idle (800rpm) my timing is all over the place. It varies anywhere from 32 up to 44 (1000rpm) my max timing is 50. How can that be, I never heard of any motor requiring that much timing advance. I am running a new MSD opti. Any thoughts? |
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Posted on: 2012/8/3 3:10
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| bam | Re: putting together my 355 LT1, questions | ||
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I am wondering if it could be my MAP sensor? Timing is tied to it (kp) in the tune, if it were reading all over the place so would the timing. I'll look at the last data log again and watch the timing relative to the MAP and see if the MAP is somewhat consent at idle or all over the place too. Any help here is greatly appreciated. I just figured the LT1 was like most other motors as to required timing advance, say around 18-22 at idle and max advance of 36-37 at WOT.
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Posted on: 2012/8/3 12:52
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| Matatk | Re: putting together my 355 LT1, questions | ||
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Unfortunately I know very little about MAP systems so I'm not much help.
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Posted on: 2012/8/3 13:34
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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| bam | Re: putting together my 355 LT1, questions | ||
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What timing are you using for your car? Have you adjusted timing yourself? Did you notice that my timing goes up to 50 degrees of advance, seems like way too much to me? |
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Posted on: 2012/8/3 16:12
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| Matatk | Re: putting together my 355 LT1, questions | ||
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50 degrees does seem like a lot. My car is slightly different than yours being a standard distributor. I have it set at stock 6* btdc then the tuning takes care of the rest. But I can guarantee you it doesn't go that high. What are your knock counts?
Matthew |
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Posted on: 2012/8/3 18:21
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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| bogus | Re: putting together my 355 LT1, questions | ||
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I was running some logs on my 92 LT1, it's stock, but the advance seems to max at 36-40*.
Is your computer currently stock? Make sure there aren't any vacuum leaks where the MAP meets the block.... As for Cunningham's suggestion on the IAC, it has little bearing on life once you get off idle. did you use a degree wheel to dial in the cam? Just because they put a mark on it doesn't mean its right... |
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Posted on: 2012/8/3 18:22
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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| bam | Re: putting together my 355 LT1, questions | ||
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Knock count on the last data log; 8172. I can't tell that any timing is being pulled out because of it either. |
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Posted on: 2012/8/4 13:52
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| Matatk | Re: putting together my 355 LT1, questions | ||
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Your knock count is 8000???? That's not good, your timing is way too advanced. If it's knocking that much your computer is pulling timing to compensate. You need to get that corrected in your tune.
I'm assuming you are also using premium fuel? |
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Posted on: 2012/8/4 13:58
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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| bam | Re: putting together my 355 LT1, questions | ||
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1. Bogus, even though my motor is not stock it seems like it would not need that much timing over stock except at idle, where I can tell that bumping the timing up really helps with cam lope and off idle power. I had almost no power before the recent tune off idle, had to slip the clutch a bunch to get the car moving. 2. Yes stock computer except for moat's prom adapter. 3. How do I check for leaks at the MAP? I am running 14" vacuum at idle, not bad for hot cam I think. 4. I agree, IAC has little to do with timing. 5. Didn't degree the cam, too late for that now. GM sold tons of them, never heard of one being out, never know though. Would that effect ignition timing needed? I suppose if it was far enough out it would kill low end tq right? The motor does pull really hard from about 4000 up to 6000. I can't remember which cam install, advance or retard that increases low end power? Thanks guys, hopefully in time I'll get this worked out. Two winters ago I installed the hot cam w/o the heads, I didn't have cam surge then. Same cam now but new TF heads and bored out to 355. |
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Posted on: 2012/8/4 14:02
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| bam | Re: putting together my 355 LT1, questions | ||
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Posted on: 2012/8/4 22:08
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| Matatk | Re: putting together my 355 LT1, questions | ||
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On my phone....I couldnt zoom in enough to see it without it getting blurry. Check the upload setting for the quality/size. |
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Posted on: 2012/8/5 1:55
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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| Matatk | Re: putting together my 355 LT1, questions | ||
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Webmaster
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Ok, I could see it ok on my desktop. You should not have knock counts of 8029. Did you install a new knock sensor? Did you wrap it in teflon tape, etc? I am wondering if you are getting false knock counts? The spark advance still seems too high, that could contribute or mean nothing. Not sure. I would still look into lowering those. Matthew |
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Posted on: 2012/8/5 15:39
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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