Lt1 cam swap l05

so as some of you may know im doing alot of work to my '92 roadmaster. after the big fail i had trying to get the rusty '95 going last year i came to appreciate the condition my '92 was in and figured id show it some much needed love in the engine department.

so i bought a cheap lt1 cam out of an ss with low miles. got a new double roller timing chain. even if theres hardly any gains with all the work im putting into this thing i wont mind. this job is alot of firsts for me; first time pulling a car engine, first time swapping camshafts first time doing internal work on a car engine. but i know i can do it and really just want the learning experience.

im working two jobs right now 5 days a week, one full time and one part time, 15 hour days. so the only time i have to work on it is weekends. im about 3 weekends in and have the motor out and new timing chain ready to install, just in the process of figuring out whether to install new factory roller lifters or leave my good ones in place. any advice? i'll update this thread as progress happens. got some headers to mount up too.

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Use your roller lifters,.  they don't lap in like flat tappet cams,. it'll be fine,.
try to find a cheap set of 1.6 roller tip rockers,.
either way you really should change out the valve springs,.

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Like so.

You may find the pin on the cam to be a little longer than the original LO5 cam. It should still be OK for clearance. I cut the pin a little just to make sure it would clear. I reused my lifters, and they are just fine. You may have a little difficulty getting them out, but if you persevere they will come out.

I would consider honing the cylinders and putting new rings in while you have it out, especially if you have over 100K on the engine. I get a little more blow-by than I like, and I blame myself for not re-ringing the cylinders. It is not that difficult, or expensive. You can use a ball hone, or a stone hone in a drill. Make sure you do not have a top ridge before you try to take the pistons out. A complete Felpro gasket set for the engine is fairly cheap.

You need a replacement chip for the computer for the different cam. You should also put the injectors from a 9C1, or a TBI from a big block in your TBI. You can use a slightly larger TBI. A 46mm will work if you ream out the intake to match the TBI. If you have headers, you may want to include that information in the description for the chip.

I did not put different rockers on mine, but it is probably a good idea. If you do so, make sure you have enough clearance, so you do not have valve/piston interference. I also used a standard single timing chain. If I were to do it again, I would probably buy a gear drive. Put assembly lube on everything just as a precaution. Keep your parts in the same location...lifters, push rods, etc. Since you have the engine out, you should at least change the oil pump connector to the distributor drive to a metal one. It is cheap, and the metal one will not break. A new oil pump is not a bad idea. Replace the rear main seal as a preventive measure...it will be in the gasket set, so use it.

Get all of the parts before you start. I ended up taking 2 months to do a 2 week job, because I would work on the engine for about an hour, and spend the rest of the day chasing parts. I saved about 20% by ordering everything I could from Rock Auto in one shot. The rest of the items I had to source locally. The metal oil shaft coupler was about $10, and was sourced at a local speed shop. If you need any hard to find parts, let me know. I have found all of the parts that it takes to do the swap.

If you want to stay with the single exhaust, you can have a large diameter Y pipe made at a muffler shop, if you take your original one with you.

If you decide to go with duals, there are already mounting holes on the driver's side of the crossmember in front of the axle to accept one like the passenger's side unit (get one from a junk yard car). Your driver's side muffler will take the place of your load leveling pump. You can make a passageway for the pipe by putting a bottle jack under the floor where you want to "raise" it, and bend the floor up a little. Work your way along the path of the pipe, and you will never see it in the passenger's compartment. The only place you need to have more clearance is under the driver's seat, and at the front of the rear seat foot area. It is a mod that I wish I would have made, so my pipe would not be so close to the floorpan.

Thanks fellas! Yea new valve springs are on the list. I've already ordered a gasket set and some other odds and ends. My ac hasn't worked since before I bought the car (about 10 years the po said) so I also bought an ac delete bracket /pulley. I've also deleted the AIR system and egr. I'd really like to learn how to flash my own chip for the car and I've been doing tonnes or research but a mail order might be the way I go.

I got the "new" cam in tonight. Timing chain installed. Crossing my fingers I found tdc properly. Gonna mock up my headers to get an idea where they'll end up. Theyre long tubes. Anywho that's all for now. Just waiting on the mail man!

I got a set of wire looms to reroute the ignition wires, and had to modify them a little to fit around the header flanges. The plugs will be right under the header pipes, so plan on putting a shield on the boots. You could use the clip on shields from an LT1 (there are only 3-4 on each engine, and you need them for all 8 with the headers). The alternative is to wrap the headers, or put heat shield socks on the plug boots. I know that you will be warned not to wrap the headers, because they will rust, but they will rust anyway unless they are stainless, and then it will not matter, because they will not rust. You still have to reduce the heat around the plug boots and wires. Be careful where the headers pass the frame on the driver's side. The brake lines run really close to them at that point, and you do not want to damage the brake fluid in them. There is also a wire bundle that passes close to the pipe beside the trans linkage pivot on the frame. You need a heat shield there as well. I do not have heat shields under the floor (cat delete) and have not had any issues with hot floors. If you are going to use cats, you need to insulate the floor on the driver's side. There are heat shields on 94-96 cars that can be adapted.

The oil pressure sender will interfere with the header. Use a 1 1/2 inch pipe nipple, and an elbow to turn the oil pressure sender to the back, The wire will still reach it when it is rotated. I would recommend a heat shield for this application as well.

You will probably have to make a patch cable for the O2 sensor, because the collector is far from the original location. You can make one with the wire from an old O2 sensor, and a pigtail for the wiring harness side. Most of the O2 sensor wires are stainless steel, so you can not solder it to the pigtail. I used a crimp connector. I used a holder for a wire clip, like the ones along the pan, and attached it with one of the flywheel cover bolts to keep the O2 sensor wire away from the headers. You might be wise to use a heated O2 sensor, because it is further away from the head, and can cool faster than the original one when stopped for periods of time. You will, of necessity, have to use a different set of connectors for a heated O2 sensor, and make a corresponding patch cable. I have some issues with hot starts, and replacing the O2 sensor helped, but did not completely cure the issue. You can hook the heater wire to the wire from the old airpump relay, and ground the other side. While you have the engine out, it is a lot easier to run the wire through the loom.

When installing your exhaust pipes, make sure your trans is in 1st gear. The linkage rotates downward, when shifted into 1st, and will interfere with the pipe if you install the pipe with the trans in neutral.

I used a piece of a junk yard trans crossmember, and welded a hump on the trans crossmember (I measured it on the car before welding it. I also closed the ends with some of the scrap from cutting the tube. If you weld a piece on the top first, and make a tube, you can cut the bottom without warping the piece.

If the picture of your car is correct and lowered, you may have some pipe clearance issues with the ground. If you do not want to clearance bend the floor pan, there is a company that makes oval pipes [You must be registered and logged in to see this link.] that may solve the issues. You can probably get away with 2 1/4 inch pipes under the driver's side seat without protruding below the frame. Once you get past the trans, you can locate the pipe beside the drive shaft like the passenger's side and use round pipe. You may also need to remove the end of the driveshaft loop so that there is only one bolt holding it (for pipe clearance) depending on how close to the centerline you mount the pipe. If I were to do it over again, I would clearance the pan, and run the pipe as a mirror image of the passenger's side. I have 2 1/2 inch pipes on mine, and that is plenty for the LO5. The pipes at the tank must be insulated as well.

Sounds like alot work Fred! Lol. the pass side manifold has a hole or is cracked or something. My motor makes a ticking noise and I doubt its a lifter. Its done this long before I bought it. I deffinately want to rid that noise. Its annoying as hell! As for the long tubes I'm not sure about em yet, I picked them up dirt cheap a few years back.. It'd be nice if I could find some short tubes or something and run a single exauhst in the stock location. I like the idea gettinga larger y pipe fabbed up. I got plug insulators already. Car is stock height but may eventually get some lower.

Don't waste your money on 9C1 or big block injectors, first off, the 454 injectors are 80lb/hr, a little big for a nearly stock build, plus you'll need to modify your TBI or a big block TBI. I just had my stock injectors cleaned and rebuilt by Witchunter Performance. Cost $54 for the pair and they're now flowing at 65-70lbs an hour depending on what PSI I run. The 9C1 injectors are 65lb/hr at stock PSI.

The 9C1 injectors will serve you well if you are not going to increase the fuel pressure. The 9C1 cam is similar to the LT1 cam, and if you are not going to change the fuel pressure, it only makes sense to have the slightly higher flow, when GM used them for a similar application. I did try the 5.7 9C1 ECM, but the custom one works better in the computer I currently have. Either injectors will fit the OEM TBI without modification. A set of used 5.7 9C1 injectors from a junk yard car is about $20. The truck injectors may be a little much for the 5.7. You could do a smoothing and cleaning up of the original TBI, and you can get a little more flow out of it. A 42mm TBI will support about 250hp. With the mods you are doing, you will probably get really close to the 250hp area. [You must be registered and logged in to see this link.]

If you want to increase fuel pressure, make a 1/16 inch thick washer to fit under the spring in the pressure regulator. If you have the need to check your pressure, get the fuel lines from a 91-93 Fleetwood with LO3/5 engines. The 91-2 will be the same shape as the OEM units, and the 93 will be shaped a little differently, but will bolt in perfectly. They all have Schrader valve ports. I am currently running about 14 PSI, and have no issues with mixture. I was running more pressure, but I was getting an occasional rich O2 sensor code. You can get an adjustable pressure regulator, but you do not need much of an adjustment to get to 15psi. When I set up my adjustable regulator, I measured the height of the spring land to the top of the bowl, and set the adjustable one about 1/16" higher for a starting point. The parts for the OEM regulator are made from pot metal, and will melt before you can get the solder off of the adjusting bolt. I melted one while testing it.

I am following this thread as i would like to experiment with some more power om my car. The ecm / computer chip? Where can i get one, and are there made for this setup or will i have to custom make one for my car ? I have vortech heads on my engine, is that going to be a parameter that will do any difference? I love this thread, thanks for sharing!

Tbichips.com

He has pre programmed setups as well as custom tunes. That's who did mine and I'm very pleased.

anyone know of some good inexpensive valve springs i can get from summit?? not sure which i should go with....

alot of my parts came in yesterday. valve springs i ordered are edelbrock's 5802. hoping i can use my stock retainers with them. i also bought a tbi rebuild kit.

Here is a list of all the sources I know of for TBI engines.
[You must be registered and logged in to see this link.]  The adapter is a PITA to work with, and you can get the fuel lines off of a 91-93 FW for cheap at a junk yard. This guy has the adjustable fuel pressure regulator.

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duals

You could run what I call "Frankenduals". With shorty headers, run the driver's side under the trans in front of the pan, and through the trans support hump beside the original pipe, then back to the driver's side to exit like regular duals, or run it parallel to the passenger's side. You could also do a similar pipe with the original manifolds and run it under the engine like a Y pipe, but continue it as a separate pipe. It would eliminate the cat because of space restrictions.

update:

sorry i havnt updated in a while. it was slow going for most of august. i was busy almost every weekend with vacations and other summer time bs. anyways i got the motor back from the machine shop in early august. i had the heads redone and new valve springs/seals put in. it was only suppose to be a week so i could get it back in time for wagon fest... that didnt happen. So instead of taking the wagon to wagonfest, we took my gfs civic

fast forward to last week and the motor was finally dropped in the car. i worked on it almost everyday last week, it seemed to go together alot easier then taking it apart. headers were installed last and i went with summit's g9001 headers which are a direct bolt in for these cars with the exception of removing the little frame brace thingys that go from the front of the frame to the engine cross member. luckily for me one was already missing off my car. looked like it hadn't been there for a loooong time. or it was never there to begin with. unfortunately the other side was still there and i had to grind it off which was a PITA and required two beers. I should also mention before installing the drivers side header i drilled a whole on top of the collector and welded in a bung for the o2 sensor. after doing some research i found it better to use a heated o2 sensor (3 wire or 4 wire o2) over the stock one wire non-heated o2. apparently the exhaust is cool enough to put the car in open loop when at a stop. not sure if i believe it or not but i bought one for cheap insurance. just need to finish the wiring for the new o2.

as of today the engine starts and runs smoothly. and it sounds b*tchin with open headers. i found it ran best at 10° advanced timing havnt messed with it too much though and my o2 is still disconnected. i just need to tidy the bay up a bit. reinstall the fan shrouds and hood and take it to an exhaust shop to finish the exhaust and do one wheel peels with my open diff. id do the exhaust myself but im tired of laying on the ground underneath this pile and im too busy with my engineering studies and work.

heres some pictures!

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