hotwired78

Hello All,

I'm new to the LS world and would like some advice.
I currently have a high mileage LS1 (176k) in an 02 c5 corvette, that leaks oil from the rear main and upper oil pan. My mechanic wants to pull the motor and do a refresh with performance upgrades.

At the same time I found a much lower mileage (64k) shortblock for a great deal and am readying to just buy that as many of the components are refreshed and new, (oil pump, TC, etc)

The motor specs below:
LS1 Shortblock, Tick LS6 Oil Pump, Katech C5R TC, Comp 224/228 114 LSA Cam, Batwing Pan, LS6 Valley Cover, Powerbond OEM Size Damper, ARP Crank Bolt

will use ARP Head Bolts(Pre-04)
maybe include BTR 5/16 Chromoly Pushrods, 7.350"

My goal being more budget oriented. Hitting 400 at the crank would be cool, but budget and value is the priority.

I have a few questions here...
1. Should I port my 241 heads that has 175k on it (max budget for reworking the 241s would be around $400) or pick up some cheap 243's off a truck salvage? (Would not plan to port the 243... overall cost would blow my budget, maybe get a local shop to just clean them up a bit)
2. What valve springs should I use with either option above that appropriately suites the comp cam?
3. That pushrod length, is it too short? with the information above, should I be buying 7.40" pushrods?

Thanks in advance for any advice here.

A.R. Shale Targa

iTrader: (2)

Definitely get the 243 heads and put some PSI maxlife 1511 bee hive valve springs on them

.boB

iTrader: (1)

400 at the crank isn't really asking much, so you don't have to spend a lot of money on go parts.

Use stock replacement TTY head bolts, and skip the ARP bolts. Stock will do the job perfectly fine, and are very inexpensive.

Used heads will need to be rebuilt - or should be, anyway. Cleaned, decked, guides, seals, springs, etc. The only real advantage for of the 243's is a slightly smaller chamber = slightly higher compression. Yes, that's a power boost, but a small one. You can your current heads to come close to that. Save the money, and start with the heads you already have.

A mild port and polish job will gain you a little power and efficiency. And it's not hard to do yourself. Check with Eastwood, they have all the tools, and even have instruction books. You can do it yourself for <$50.

I also like beehive valve springs. Look in the catalog and see what Comp Cam recommends for each cam, and follow that. I bought mine directly from PAC and saved a little money.

Do not buy any push rods until you put the heads in place and measure them. Lots of posts here about proper measuring techniques. Getting it right the first time will save a lot of hassle.

Mercier

iTrader: (15)

If you are porting, I think the LS1(241, 853) heads can get to the same place as a 243. And max ported both will end up almost the same.

But I think you indicated that only advantage of the 243 is the smaller chamber. To my knowledge, the port design is superior as well. It's not the same as going to a Trick Flow or similar, but I've seen several flow charts that support the 243 ports flowing about 10% better in stock form. For something you can commonly get used for $350, that's motivating I think.

Did I miss something?

Still with work a 241/853 can certainly be made to outflow a stock 243.

.boB

iTrader: (1)

I believe that is correct, the 243 has a better port design. If you're looking for significant power, and are willing to add the supporting parts to make use of it, then it's probably worth the money to look for a good set. But, the OP isn't looking for that, and has a tight budget.

hotwired78

bought the PSI 1511ML springs and btr ti retainers
since i'm on a budget right now, i've skipped getting different heads, will just have them cleaned up, decked, etc. for about 250 (no port), and stick the 241 heads back in.

used that cost savings and picked up some new obx LT headers for 500.

thanks for the feedback everyone... any further advice is appreciated!

looks like its actually a 224/228 .534/.537 112LSA cam and not 114... i made a correction above.
comp's suggested spring is shown below. am i still okay with the PSI1511ML? can I reuse my valve locks, seats, etc.? I may or may not buy new pushrods depending on the length measured after the heads are on.

Valve Spring Kits 26918TI-KIT
COMP Cams 26918-16 Details

Chevy LS1/LS2/LS6

Performance Street
Designed for hydraulic cams

.625'' maximum lift
Originally designed for LS1, LS2 and LS6 engines
Will work in 5.7 Hemi engine with part 249-761 or 249-762 retainer as well as many other engine combinations.

Specs
OD: Top 1.075" Bottom 1.310"
ID: Top .650" Bottom .885"
Seat Pressure: 125 lbs @ 1.800''
Open Pressure: 367 lbs @ 1.150''
Coil Bind: 1.100"
Spring Rate: 372 lbs/in
Specifications:

Open Height (in.)1.15Installed Height (in.)1.8Installed Pressure (lbs.)125Spring TypeSingleCamshaft TypeOEMCoil Bind Height (in.)OEMInside Diameter0.660/0.885PositionN/AOpen Pressure (lbs.)367CoatedNoDamper Spring IncludedNoInside Diameter of Outer Spring (in.)0.65Number of Springs Per ValveSingleOutside Diameter of Outer Spring (in.)1.075QuantitySold as a set of 16Spring Rate372 lbs./in.Valve Spring StyleBeehiveManufacturer's Part Number:26918-16

Mercier

iTrader: (15)

The PSIs are fantastic springs and I think will be great with that cam. A tiny bit overkill but they aren't heavy so I don't think you'll sacrifice anything. Unless you are running higher than stock ratio rockers and then they are likely right on.

It occurs to me that cam would probably do with LS6 springs but since you already have the PSIs, run them for sure. They are a true drop-in meaning you can use your same seats/seals, locks, and even retainers.