Gordonm

Little motor progress tonight. The cam and springs and titanium retainers came today with other small parts. I got the cam in and you can see the 3 bolt cam vs the other picture with the single bolt from the post above. The springs are a much better and higher rate than the stock spring and the titanium retainers make for less weight at the end of the valve. None of this stuff is cheap though. Should make good power though. That is what is important.



Half the springs done on this head



All springs done now. Waiting on the trunion upgrade which should be here tomorrow so I can bolt the rockers back on.

riggs 74

Yes the parts for the LS are expensive. Good thing you didn't pull the heads to change those springs, the head gaskets are like $75 + the cost of new Head bolts, they are a one time use bolt. Yes these LS motors respond really well to just a cam alone.
Any plans for the appearance, Like paint or polishing, nows the time while you have it apart.

Riggs

Gordonm

Thought about pulling the heads and having them ported and cleaned up but for another 30 or so HP it was not worth the 2K it would have cost by the time I was all done with it. If I want more HP down the road it will be a lot more in terms of a blower. That is getting way ahead. This should be enough for now. Most of the fasteners on these are one time use. The gaskets are all different but they work very well. I am sold on the LS design after having these apart and I have not even driven it yet.

No real polishing, probably a set of different valve covers and coil relocation. The Ac compressor is polished. Not a chrome guy at all. I like things clean and organized.

Solid LT1

Gordon are you staying with stock push rods? I have heard these are a weak link on LS motors. Maybe the LS3 is better but, you should check it out on the LS1 forum or C6 forum here. I was glee years ago by one of our areas better LS timers that pushrods are the weakest link of the LS6. FYI the tool steel retainers are only 2-3 grams heavier than titanium on the beehive springs.

Solid LT1

Damn I hate the spelling corrector on my fone (sic)

riggs 74

Funny how we think alike, I was going to buy a fast 102 intake setup but for the money and only gaining 20 HP it's not worth it. I'm also thinking about a blower, but like you said, that's latter.

The design of the LS is so much better to work on compared to the Gen 1 motors and a lot stronger as well. I have a TON of money going into this LS swap, but I'm glad I took the plunge because I don't think I would be as happy with the plans I had for the old small block.


Riggs

Gordonm

I see your build is very much like mine. Definitly not going the cheap route but it will be done right and how I want it. I looked a tthe intake also but on the LS3 it is only worht 5 to 8 HP over the stock one. I won't go back to the older style motors after this one. Technology is a good thing. Modern drivetrain and comfort of AC with the classic lines. What could be better? Well maybe a new ZR1 would do.

Gordonm

I have spent more time on LStech and the C6 forum than the C3 forum lately. Most of the time the pushrods are only changed when they are putting on different heads or milling them and they require different lengths. My cam is definitly not that radical. Just an increase duration and some lift. 223/231 and .610/.617 lift. The LS3s seem to live pretty well on the stock pushrods at this level. That 2 to 3 grams allows me to run the Comp behives to 7K without a problem. Probably overkill but better than floating a valve at that rpm.

Gordonm

Here is a mod that is not really needed but it is like buying insurance. The trunions and bearings on the rocker arms on the LS motors have been known to fail on occasion. This puts a lot of tiny rollers throughout the engine pretty much destroying the motor. The stock ones are not captured bearings and there is nothing but a press fit holding them in the rocker arm. Along comes Comp Cams with a solution. Upgrade the bearings to captured bearings and make the trunion larger and with better steel. Like I said this is not needed but for a little over a hundred dollars and about an hour with a press you can eliminate this potential problem.

Here is all the bearings and trunions after pressing them out.



Comparison of the stockers vs the new bearing



New vs old trunion. Quite a bit larger



Pressing it all togther. You press in one side. Drop the trunion in and them put the other bearing on. The washers they give you and are perfect spacers for pressing it together. After they are done a snap ring goes on either side so they can't fall out.



It won't add any HP or bling but it gives me a little piece of mind at 6500 rpm.

sokoloka

I am at the stage of plumbing my LS3 swap; luckily with the body off the frame. You think the stock steel lines should be enough to feed the engine? How are you running the return?
I picked up a new LS3 build from TurnKey and when running over the details with them I was given the impression that the stock main line didn't offer enough flow for the engine...
I'm currently looking at routing options for full braided but wouldn't be opposed to the stock steel if possible.

Gordonm

The stock 3/8 fuel line will feed enough fuel for a 600HP LS motor with no problem. Remember you are pushing the fuel rather than sucking and it is being pushed at about 60 PSI. Do not run braided fuel line the length of the car. I did this a few years ago with the older injection system. The braided line stinks and I mean smells. It lets out enough vapor to stink up the garage overnight. Try to run as little braided line as possible. I am actually not going to run any braided line. The new twist lock lines seem to be better and is easier to work with and does not stink. The return line is just going to be a short line running back to the top of the tank right next to the pressure line. That is the beauty of this system, the lines are short runs and the the return is right there with the pressure line.

On my old injection setup I ran a 3/8 fuel line at 42 psi and it was making around 500+ HP with no drop in fuel pressure. Unless you are boosting or running nitrious you will be fine with 3/8 line. The Walbro pump will also feed about 600HP.

Hope this helps. I will have complete fuel line setup soon as I get the fuel line in. Pictures will follow.

68 NJConv 454

Very nice job! I've got to get down to see you sooner than later.

Shark Racer

What are your thoughts on return line? The LS3 is returnless, isn't it?

Do you happen to know what year the vette motors switched over to returnless?

I'm considering going EFI, not sure if I wanna go with a drop-in kit for the 350, or go with an LS. Being that my car is carbed, it'd actually be easier in the long haul to drop an LS in. The emissions systems are much less complicated, and I'm actually learning my way around ECM tuning.

68 NJConv 454

subscribed. Keep those pics and commentary coming!

Gordonm

Yes the LS3 is so called returnless. If you look at the filter/regulator you will see two lines off the back side. One is pressure and one is the return. So it does have a return it is just a short return. Most FI systems return from the motor back to the tank. Long runs. Not sure when they switched over to the newer design but it has been for a while.

The so called drop in systems, some are pretty good. It will be cheaper if your motor is in good condition to drop on a system rather than go to the LS motor. Everything is different on the LS motor. Mine is definitly not a budget build at all but I am trying to keep costs down, don't we all. It is still costing a bundle to do it the way I want to. If you want an LS motor than have at it. Everything is doable for sure just up the credit card limit!

0Ian@Keen Parts

Alright, two things I see here....

You are really playing with fire with the 918 spring and that cam. Straight from Comp...

Granted I understand that says "most", it's a very sensitive are. That cam may not have a ton of duration, but with those kind of lift numbers, and the kind of RPM you want to turn, those springs are like playing russian roulette. I had them in an off-topic car using a 232/234 .595/.598 cam in an LQ4 that only spun 6200RPM, and was nervous then. Just my honest opinion, from the talking I did with Comp, and with many a set of broken 918's out there, I would seriously reconsider your valve spring choice to a good set of doubles.

Those pushrods are not up to the task of 6500+ RPM with those lift and duration numbers. At least not for long. For the $100 you're going to invest (TSP, Comp, etc.), a set of pushrods is just a basic part of the cam swap. If you held a chromoly pushrod next to a stock one, you'd understand.

FWIW, I've run the stock rockers to 8k+ RPM with zero issues for many passes, and many street miles, without the trunion mod. But I understand the overkill mindset, trust me.

I hope you don't take this the wrong way, and I'm not telling you what to do with your car or your build, I'm just giving you some insight from what I've experienced through the (more than a) handful of cam swaps I've been through with these motors, and save you some headache in the long run.

Gordonm

Those are the old 918 springs. Check out the new specs.
http://www.compperformancegroupstore...Category_Code=
They have gone with better wire and are good up to .625 lift. This is the same spring they did the cam comparison on the LS3 motors and they ran up to a .640ish lift with no problem. They also spun the motor past the 6500 rpm threshold many times with no issues with pushrods or springs. No question the stock rockers are a good piece and probably would never give me any problem. But I did it anyway.

PatsLs1vette

Wow first time back on here in a few months you got alot accomplished Gordon,looks great.Ill keep checking back everyday now.

Shark Racer

I would probably be going EZ EFI if I stuck with the 350. The trouble is that would put me into the smog ILLEGAL camp in CA, even though I could get the car running better than otherwise. LS series is tempting because the 01+ setups have so much less crap in the engine bay, especially compared to a 78 'vette. Much easier to keep track of what's going on, where everything goes to something that makes sense. Ported vacuum switches, solenoids, etc. What a pain in the ... you know.

I have a 2009 Z06 sitting next to the 78, so I'm not horribly tempted to build the 78 up much. I would most likely put an LS1/4L60E in the 78. It has a 700R4 already, so the only real work needed is plumbing the return, the P/S stuff and doing the wiring. I'm not afraid of EFI at all.

I'm probably going to put your thread in my archives... tons of info here and great detailed photos showing off the gotchas.

SmokedTires

Looks like your doing lots of great things while your there, takes a bit longer but worth the peace of mind