Re: Cam Replacement
 

my 283 is .030 over

Re: Cam Replacement
 

Faribran, By chance have you had your engine dyno'd?

Re: Cam Replacement
 

I remember that Horsepower show, they built the 283 for the Trucks Show.
Its like they showed it one time, cause I never saw it again. Cant view it online but I remember they got about 270 hp from the engine. Just dont know whats in it.

Re: Cam Replacement
 

I didn’t see that episode, I take it was a budget build?

Re: Cam Replacement
 

Yup!

I was built on a budget for sure.

Very modest 283 build.

Re: Cam Replacement
 

So heres what came out, a Isky Megacam 270 Hyd. The stats listed on the site said I should have 9 to 10:5 compression and a 3:73 to 4:11 rearend, stock converter, auto or manual trans. This is the cam listed for 283 and 327 engines if you have this setup. I know my compression is in the 9's but I dont have the gears. So it will be a step down, probably a 260 Hyd is what they list for 3:08 gears.

Re: Cam Replacement
 

So what cam are you going with now?

Re: Cam Replacement
 

So did you determine that you really did have a lobe go flat?

If so, I wouldn't "just shove a cam back in and call it good". The metal particles are still in there. The chances of another failure are much greater that way.

Re: Cam Replacement
 

rollers!? didnt see that comming!!! looks sweett!!!

Re: Cam Replacement
 

X 2 better off to do it rite the first time. I would use a comp cam part#12-300-4. Great cam for your current set up and will really make a noticable improvement. I have used this cam a couple of times in customers projects and had very good feedback. If it did really lose a lobe you need to find the cause of the problem and fix it also. Just my 2Cts

Re: Cam Replacement
 

The rollers were on the motor when I bought it. Only thing I had to add was a new water pump 2 years after I got it. Thats it other than the performance mods I added. Engine been running fine for almost 12 years till this problem.

Re: Cam Replacement
 

Thanks for the part number for the cam, I will check it out. Isky had one for my setup also and there only 5 miles from me. So I was going to stop by there and inquire. The cam lobes look a bit worn down and they are pitted around the lobes.

Re: Cam Replacement
 

Update on install.
I went with the Edelbrock 2102 Cam and Lifters, could not find the Comp Cam in stock, hate stuff shipped to me. Anyway, cam and lifters went in no porblem, got to roller rockers, had too much torque on the TQ wrench, snapped a stud. Now I have to pull the heads. Problem, headers are welded to the collector due to me trying to eliminate exhaust leaks, and I need to pull the headers to get to the head bolts. So my $150 simple cam change has grown into a decision, do I keep messing with this 283 or say the heck with it and put my energy into the 350 block I have on the stand?
The 283 was to use for taking stuff to the dump as we redo our kitchen, did not want that stress on the 350.
decisions decisions!

Re: Cam Replacement
 

So did the OP make sure there was no cam lobes wiping out on the old cam? If not... that new cam and lifters will be junk in short order...

Gary

Re: Cam Replacement
 

I'm just as concerned about the "torque wrench" and "snapping" a rocker stud?

This seems to me like a case of not understanding how the locking set-screws from the roller rockers work. There is no reason to ever break a rocker stud by tightening it!
The only thing I can see here is that the Allen screw was in far enough "stop" the nut's adjustment?

Re: Cam Replacement
 

Longhair... I was thinkin' the same thing on the locking set screw. yikes! :eek:

When I lost a cam awhile back in my 350... I completely disassembled the engine, and cleaned it, then cleaned it again, and then cleaned it again. Solvents, pressure washing, and soap and water... I had to replace cam bearings and all the main and rod bearings too... Also replaced the oil pump. I lost 2 lobes and it really ate in to the lifters too. I was shocked at how much metal material was in that engine.

There was still metal particles trapped in the oil pan baffle. No matter how many times I tried to run solvent through it to clean it... there were still metal flakes. I eneded up going the "safe" route and just putting a new oil pan on it.

Gary

Re: Cam Replacement
 

Your right, I did not understand that I did not need to torq down the rocker screw. I did a search and came up with torking down the studs, not the screw. Also, not sure if you can see it from my pics, but there is no Allen screw adjustment on my heads. The valves are in and the rockers are on a stud with the nut, thats it.

Re: Cam Replacement
 

Oh yeah, I have taken apart quite a few like that. It's incredible how much of that metallic stuff there can be. You really need to remove all of the oil galley plugs and run the long "pipe cleaner" type brushes through everything.
As soon as one lobe fails, the particles from it and the mating lifter fling around in the oil and get between others. It makes them fail faster....snowballing.

Re: Cam Replacement
 

Thats why im thinking of just doing my 350 and calling it a day.
I dont want to get into spending too much money on a 283 that I can put to a stout 350.

Re: Cam Replacement
 

Well, there should be.
Those are what is generally refered to as "poly-locks" style rocker adjustment nuts. They are not like the factory "prevailing torque" nuts. The factory nuts are "crimped" slightly, which acts like a nylon lock nut, but is able to withstand the hot oil.
Roller rockers use a taller nut that puts the hex above the slot in the rocker arm body. All of them that I have ever seen use a different method for locking them in place. The taller nut sticks up above the stud. This space allows the use of an "Allen" screw threaded down the middle. This screw binds against the top of the stud and locks in the adjustment.

Re: Cam Replacement
 

If you look at the roller rocker next to the broken stud, you will notice the adjustment nut and theres no allen head to adjust. Its been running like that for over 12 years. Your not the first to tell me it should be some adjustment screw, but its not.
Maybe that nut is the adjustment screw.

Re: Cam Replacement
 

I say disconnect all your hangers for the exhaust so the headers will move then you can access the head bolts, drop another set of heads on it, and keep that 283 going.

Re: Cam Replacement
 

It's not an "adjustment" screw, the nut itself is the adjustment. The Allen screw is the "locking" mechanism. I work like "jamming" 2 nuts together to lock them to a bolt.
I have never seen this style of nut run w/o the lock screw. I am surprised that it would stay in adjustment.

Re: Cam Replacement
 

I would think they would back out pretty easy over time with no way to lock them on there. Maybe the OP can post another pic of just the rockers from a top view.

Gary

Re: Cam Replacement
 

I do have a set of heads for the 350 with 190/202 ready to go on the block.
Figured that would raise my compression up a tad bit too much. LOL

Re: Cam Replacement
 

Vince, check your casting numbers for the heads at http://www.mortec.com/
That'll let you know if the new heads will raise your compression too much compared to the old ones.

Re: Cam Replacement
 

Thanks Sin. Man im so frustrated right now, I finished the lower half of the cabinets for the wife this weekend to give me time to figure out which way I was going.

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Hang in there, you'll get it sorted out. :chevy:

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Ok fellas, heres the deal. It was not my cam after all, it was the first 4 head bolts on the passenger side right under the plugs, they were loose, finger loose. After 12 years I guess they did not have enough loctite on them.
That was my exhaust leak.

Re: Cam Replacement
 

Exhaust leak from head bolts? You have blown the head gasket, and probably should have a coolant leak too. Those bolts hit coolant, if they are loose, they should leak, even if the gasket wasn't blown. But if you had an exhaust ticking "leak" from those bolt being loose, the head gasket is definately blown.

BTW, don't use thread locker on head bolts. They shold have thread sealer on the ones that hit coolant and motor oil on the ones that dont. Those bolts stay tight from "stretch"

Re: Cam Replacement
 

The thing is, I did not leak coolant, they were loose enough to make a noise like an elf hitting metal with a hammer when I step on the gas. At idle it ran normal. Head gasket was fine and my cylinder walls were in amazing shape.
Anyway, I changed the cam to an Edelbrock RPM, but my Iski Cam was in perfect shape after I got it inspected. Did change the head gaskets, in fact any part I pulled off, I changed the gasket or added thread locker or sealant.

Re: Cam Replacement
 

So I decided to use the heads I had for my 350 seeing that a machine shop wanted to charge me $450 to add new stems and harden seats for unleaded gas on the heads that came off the 283. I figured that was too much for 283 heads, save that money for the 350. Took off my timing cover without removing the oil pan, well 12 years of sealant, I just could not drop the front of the pan, it had to be pryed off. Now I have to get it out to remove the cork gasket from the pan and the engine.

Re: Cam Replacement
 

As I was installing the HB, I lubed the shaft and inside of the HB. I slided it on as far as I could, then installed a bolt thats part of a tool that will push the HB on the crankshaft. Well as I turned the nut that pushes it on the shaft, something happen, the tool expanded on the bolt and now the bolt is screwed into the crankshaft. You can see it in the pictures.
Now I have to drill a hole in the bolt and use an ezout to back it out.
One more reason to say the HE-double tooth picks and buy that 350 from United Engine.

http://www.unitedengine.com/index.ph...mart&Itemid=55

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After being talked out of getting rid of my truck, I decided to keep it.
Then came across this on Craigslist.
Im Back!! Now im going to need a lot of help. LOL

Re: Cam Replacement
 

Fwiw I put 350 aluminum L98 heads on a smaller bore before (305 which is 3.736 bore) but had to use 350 head gaskets and it ran fine. 350 heads will work and I am guessing the Vortecs would work also as long as you don't add large valves.

Re: Cam Replacement
 

I'll keep that in mind. For now im going to use the LT1 engine, less the TPI for now. The TPI will be added later on when I start a complete build, I need a motor now to use my truck for home repairs, then I can tear it down and build it the way I want.