5.7 Vortec LT4 Hotcam Install Pics and Information
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5.7 Vortec LT4 Hotcam Install Pics and Information
Well guys, I recently installed a LT4 Hotcam into a 97 vortec motor with a ton of help from Melonhead. I figured I would post up on some part numbers and such that I ran into during the swap. I searched many different forums for help on this, so this thread is meant to be a help to anyone that decides to do the install.
First off, the motor is a carburated 97 Vortec 350 from a truck. It is in my 88 camaro with a stock 700r4. From what I have read, these motors come stock with 255hp. Or atleast that is what GM claims. The motor ran great, had decent power, but I wanted more. I wasnt looking for all out horsepower, but a good streetable cam that would work well with the rest of the engine and that would wake that motor up. I decided to go with the GM LT4 Hotcam. The cam is very streetable, has a smooth idle, and a good powerband that doesnt go too high in the rpm range. The cam is listed as NAL-24502586 (summit number) http://store.summitracing.com/partde...6&autoview=sku
It is a hydraulic roller with 1,500 - 5,800 operating range, 218/228 at .050, .492 lift with 1.5 rockers and a 112 lsa.
The main problem with the vortec heads as many people know is the lift restriction of .480 If you have the heads off the engine, I would recommend having the correct machining of the valve guide done and have screw in studs installed. However, you can make these heads work with larger lift cams without removing the heads. This is where Melonhead was a lifesaver for me. If you use the GM LS6 beehive valve springs (GM PART # 12499224), Comp Cams retainers 787-16, and change the umbrella valve seals to Sealed Power Part # ST2015, you should be able to get up to 0.550 lift. (I am currently only running .492 lift with this combination with no problems, however in the next couple months I will be swapping to 1.6 full roller rockers giving me a lift of .525.)
Swapping the valve springs is simple. Im not going into the details on how to swap valve springs on an assembled engine, you can find that elsewhere. I will say that the new seals go on fairly easily and if you put some oil on the inside it will help it slip on. Using an old retainer from a spring you just removed, press down on the seal until it fully seats on the bottom. you dont need to buy one of those installer tools for $30. The ls6 valvesprings are alittle tight to install sometimes. I had to put some of them under a hairdryer for a little bit for them to slip on. It was tight, but not tight enough to warrant a concern.
One of the huge downfalls of doing this swap with the engine in the car is the stock plastic timing cover. I first started by removing several of the front oil pan bolts. Most of you have pulled a timing cover in car before, so not much detail in that respect. The stock oil pan gasket is a one piece rubber style so be careful. While I was working the cover off, the bottom corner broke. Cheapest place I found was summit for replacement NAL-12562818 $23. The summit piece is built by GM and comes with gaskets and bolts. The crank position sensor holes are in the cover, but if you are using one, you must cut it out yourself.
The crank position sensor trigger wheel is pressed onto the crank in front of the crank sprocket. A screwdriver was all that was needed to pop it off. Gently pry on one side then the other until it comes off the keyway. The rest of the cam change is straight forward, pull spider, pull lifters, pull cam, reinstall cam, reinstall lifters, reinstall spider, reinstall timing gears. For reference the timing set I used was Cloyes CLO-9-1157. Also from summit.
If you take your time, you can reinstall the timing cover with the engine in the car, without dropping the oil pan. It just takes time, patience, and a steady hand. Do not get too forcefull or you will break it. From here on out it is basic reinstall. I set the hydraulic lifters at 1/2 turn.
Distributor gear. That is the big question I had. Do you have to run a bronze gear? No. Since these motors come originally with a roller cam, the stock gear will work with this cam. GM cams use a melonized distributor gear on the cam. However, if you go to an aftermarket cam, you might have to change out since they are billet. But for the GM hotcam, your old distributor gear will work.
I am running an Edelbrock Performer RPM intake with a holley 600 with vac secondaries. I have alot to do under the hood when money allows. Full roller 1.6 rockers, custom wires, custom air intake, and a basic cleanup of stuff under the hood.
The idle didnt change much. It almost sounds exactly as it always had. After some linkage issues I had, I could tell a huge difference in the motor. That cam really woke it up. I have realized now I need to change out the governer in the transmission to let first gear turn higher before shifting. I havent been able to do any tuning to it lately. The first couple of hard runs has given me a nice little noise somewhere in the driveshaft or rearend. Got to fix that first. I am running a stock converter. The only issue I have with it is that at times when you are coasting around a turn or down the road, you can feel the car want to "buck" alittle.
http://www.grandsportregistry.com/dyno.htm This is the registry for the 96 LT4 cars and the mods done with dynos done. Most show atleast 300hp at the wheels. I have not been able to dyno, but I can say it is alot more than the 255 the motor started out with.
All together I am completely happy with the swap. I have around $600 in the swap and it is definately worth it.
I will post up more as I get the time to tune. Here are a few pics.
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
Quote:
Originally Posted by five7kid
Links aren't working.
What intake are you using? A Performer RPM would be required to get the upper RPM power. A 650 carb would also help.
Stock stall is a killer.
I am running a Performer RPM. Carb is based off what I had at the moment. I plan on updating it sometime. Money constraints are too much right now. Same goes for the converter. Definately going to update sometime. The reason for mentioning that I am running a stock converter is not to say that it works just as good, it is to show that if you are in a tight budget, that yes a stock converter will work for the time being. I would definately recommend atleast a 2000 stall. But if you get into that, I would also recommend going with a higher compression ratio, bigger carb, air-gap intake, stall converter, etc. That is not my point however. Just putting information out there for people that are in the situation I was in and couldnt find any information.
The pics would work if the word " Red-neck" wasnt prohibited.
Last edited by 3rdgenmaro; 04-27-2009 at 06:09 PM.
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
as an update, car runs great. No problems or regrets. Very happy.
I swapped in a 94 Z28 rearend with disks, posi, and 3.73 gears. I took it out on the road and had some severe wheel hop issues. I installed a set of Lakewood LCAs and that solved that problem. However before I could get to the drag strip, my 700r4 is shot. Started slipping yesterday.
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
Awesome sounding budget build 3rdgenmaro. Thanks for all the information too. Nice to have part numbers to reference.
Will those sealed power positive seals (Sealed Power Part # ST2015) work on my 416 casting heads with-out machine work? I'll be using comp xe268, comp springs (981?) and i have std and off-set locks i can use. Trying to do a budget build atm my self.
Good luck with that 700r. I'd do a decent rebuild on that thing. Z-pack 3/4 clutch pack, shift kit and cooler would help survive all that "new" torque.
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
I am having trouble finding the valve seals. I found one place that had 8 of them but I am guessing I will need 16 to do both heads. Do you have any idea where would be a good place to get the other 8?
but it looks like they are out of stock on them. You might be able to call up Napa, Advance, autozone, etc. and give them the part number. They might be able to cross reference the number.
The seals are actually designed and produced for 1984-1990 Dodge Daytonas. You can check that site I posted, it lists vehicles under it.
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
yeah those things are going to be a problem to find I believe. Heck i guess I will just order another 8 from someone and wait the 55 days for them to get here lol. My motor is still in pieces right now so I am in no great big hurry and this way seems to be allot cheaper than buying each individual Comp Cams piece I was going to have to buy. When you say you had to use a hair dryer to get the springs on what was the reason for that if you don't mine me asking, to get the seals warm so the springs would fit over them?
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
no, I just added some heat to the springs to get them to expand alittle. It was pretty cold in the garage when I was installing them. Some of the springs didnt really want to go down all the way on the seats. Just heated them up alittle until they were warm and they slipped on alot easier. Nothing major.
If your motor is in pieces, I recommend doing the right thing and having the guides machined down. Just to be certain.
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
I went ahead and ordered them from rockauto and got this message "Unfortunately, SEALED POWER Part # ST2015 is on backorder. The Manufacturer is not aware of when the part will be back in stock.
It appears that we may have alternates for your application, Please call our toll-free customer service number at 866-762-5288 to discuss this further." so if they have any seals from the car mentioned above it should work correct? what engine does this vehicle these are supposed to fit have in it
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
go back to rockauto's website, punch in the part number in the catalog.
when it comes up, click on the blue part number, it will give you a list of all the vehicles that it fits. The engine is not listed, but there are several vehicles listed. Autozone should be able to find it for you.
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
I got the seals today and at first i didn't think they were going to work but after working with them a little I finally got them. The problem is the Sealed poewr parts have a metal ring around them at the bottom which stops them from installing all the way, the fel pro parts doesn't have this ring so i just took that ring off and after working with them a little they finally went on
Re: 5.7 Vortec LT4 Hotcam Install Pics and Information
Quote:
Originally Posted by 89RSTBI
I got the seals today and at first i didn't think they were going to work but after working with them a little I finally got them. The problem is the Sealed poewr parts have a metal ring around them at the bottom which stops them from installing all the way, the fel pro parts doesn't have this ring so i just took that ring off and after working with them a little they finally went on
they must have changed then. Mine from Sealed Pro didnt have anymetal either. I put alittle oil on them to help them slide, then took a retainer and pushed them all the way on.
