JimMueller

iTrader: (9)

I've got glitter in my oil filter, and I've got ticking/tapping coming from the right side of the block. It's my only vehicle, so I'm trying to balance 1) a good replacement engine which could be swapped in rather soon, and 2) keeping costs under control so we don't have to cancel our family vacation in August. The costs and delay in waiting for disassembly and cleanup of the current block doesn't seem worthwhile.

Below is what I have on my current longblock.. looking for reasons to stay with an LS1 vs. converting to a LS2 or later design. I don't want ridiculous power, but would like a solution which easily gives me 400-450rwtq over most of the RPM band for a decent price. It'll never be blown or use nitrous. I do not like the noisy forged pistons I've had in the last two motors, and had a recommendation to swithc to a Mahle 40* series piston which would be quieter but still more reliable than the hyperteutic(sp?) factory casting. When I was autocrossing I liked to shift late to take advantage of gearing, and I still like it.

What are the incompatibilities, and/or what else would I need to upgrade (injectors, clutch, etc)?

stock k-member
LS1 oilpan
Katech oil pump
Turn One power steering pump
LS2 water pump
LS2 160* thermostat
LS2 timing chain
stock crank*
ARP main studs
Eagle 6.100 rods*
ARP rod bolts
Wiseco 3.905 pistons -2cc*
Total seal rings*
224/230 cam*
cometic gaskets*
LS7 lifters*
TSP PRC 5.3l stg2.5 heads, ~59cc chambers
ARH 1.75" headers
ARP head bolts
Manton 3/8" pushrods (7.35, I also have Crane 7.4's)
stock rocker arms*
center bolt valve covers*
Vengeance ported Fast 92
BlueMax 90mm throttle body (no MAF)
Fast Toys 85mm lid
stock injectors altered to flow 42lb (otherwise fuel system is completely stock)
LS7 clutch with Fidanza 13lb flywheel
steel driveshaft
10-bolt

* I would be replacing these at a minimum, either because I believe they aren't physically compatible with a LS2+ solution, or their state is questionable at this time due to the noise.

So, what is the most cost effective solution?

transam69230

iTrader: (49)

Well you would need a new block to switch to ls2 or ls3. Then you would need new front and rear covers as well as a new valley cover. Then an adapter harness for the cam sensor because it is moved to the front timing cover on the ls2 stuff.

Ls3 is whole different story, you would need new heads, intake manifold, rocker arms, and the other stuff I mentioned as well to convert.

KCS

iTrader: (20)

Any objection to doing an iron block? Just the cost of the block alone could be cut in half, and finding a Gen III block wouldn't require you to buy the LS2 conversion, as mentioned above. You could also keep your headbolts, since they changed ~'04. You would only have to have a hole drilled and tapped for an accessory bracket, which you or any competent machine shop could do easily.

Hopefully, your crank and rods would be salvageable, but a 6.125"/.927" pin rod would open the door to a wider selection of pistons.

JimMueller

iTrader: (9)

Don't like the additional weight of an iron block on the front end for a car built to do more than go straight

My friend who made the recommendation on the Mahle's also has a a few spare LS3 parts from a previous situation he helped with. IIRC, it's a new LS3 block, new LS3 crank w/ 24X reluctor, and 1800mi LS3 heads & valvetrain.

I agree on the rod/pin issue... I had a real problem trying to find a .945 piston set to mate to those 6.100 rods last time.

Whistler

iTrader: (46)

A 4032 forged piston will reduce the cold forged piston slap as long as the p/b clearances are clearances accordingly.

JimMueller

iTrader: (9)

Know anyone who knows how to do that? ;-) I'll give you a call probably within an hour or two with more questions.

Justus67

iTrader: (3)

LQ4 or LQ9, most cost efficient and easiest switched over. Just keep in mind the LQ4 pistons are dished .011. They offer iron strength, more cubic inches and interchangable parts from your LS1 to the new motor. I bought my complete motor for $1500, short blocks are way cheaper.

JimMueller

iTrader: (9)

Changing the vacation plans, so I have a bit more money. I've got about $3500 immediately to get things rolling towards getting a motor back in the car. I would like the car to not be any weaker at any RPM than what it is now. I want to stick within the LS7 clutch limits. Only aluminum blocks and it stays naturally aspirated.

Some options:
- rebuild the current motor and replace/upgrade as necessary
- new 347 LS1 and move over parts from current motor and replace/upgade as necessary
- new 383 shortblock block and move parts over and replace/upgrade
- used/new LS2 402 bottom end with my current PRC 5.3l stage 2.5 heads & ported Fast 92
- used/new LS2 402 shortblock with 1800mi LS3 top end and custom cam
- new LS3 shortblock & crank w/ 24x, 1800mi LS3 top end. Need to buy rods, pistons, lifters & cam and anything needed to connect it to a 98 F-car.

The least expensive 402 LS2 I've found is TSP's @ $4009, but I've seen and heard mixed reviews on their quality control. A new LS2 block is ~$1100 through GMPP. Which inexpensive & reliable rods have the least balancing problems? Which inexpensive & reliable 4032 alloy pistons are out there? If I bought the LS2 parts individually, I was leaning towards Scat rods, Mahle pistons, some sort of link lifters and a matching cam.

Thoughts? What would give the best results for my application (street/autox/hpde) within say a $5000 budget to get it running again?

Austinma62

It all depends on how much power your looking for. Theres several people on here with 383 LS1's making great numbers. That would be one of the more cost effective options.

JimMueller

iTrader: (9)

Most of my autocrossing will be in second gear, which means if I need to slow down for a really tight maneuver then I either downshift to 1st and blow the tires away coming out of that maneuver, or shift to 2nd and have traction but no acceleration. Thus I need lots of oomph from say 2000RPM and want to carry it as long as possible to take advantage of gearing.

The few 383 shortblock prices I've seen are only a couple hundred less than a 402 LS2. I think the 402 displacement would be better than the 383 at low RPM with my current heads. The 402 with the LS3 heads I think would rock, but I don't think that's in the budget.

Titanws6

iTrader: (35)

Again.... I remember seeing your car on Roberts lift less than a year ago with the motor out, dang that sucks.

brian g

iTrader: (1)

Get the 402 sb and use your cleaned up heads (good VJ &blend) use a modest cam and get a good tune.

JimMueller

iTrader: (9)

Are you sure it was last year? I thought I found a receipt that indicated it was 2008. hmmm... oh well, doesn't matter at this point.

joshrhea

I hear good things about the LQ9 not a bad price on them either.

Whistler

iTrader: (46)

Mahle and SRP both make a nice low expansion forged piston, and I haven't had any problems with Eagles, K1s or Compstar for inexpensive rods. The Eagle and K1s can both be had for $400-$500. I have no experience with SCAT but others use them with success.

JimMueller

iTrader: (9)

OK, a couple of questions for the LS3 build...

balancer: I can (should?) re-use my non-SFI ASP underdrive pulley?
injectors: I can (should?) re-use my 42lb LS1 injectors with the LS3 intake? If yes, how?
timing chain: I've read some horror stories about the LS3 timing chain... what is the best solution? Which dampner?
Coolant: Crossover pipes, caps, etc can be re-used, but I need a new valley cover (I have the LS6)?
Throttle body: I can re-use my BlueMax 90mm throttle body?
PCM: Keep 98 or upgrade? New harness?
Compression: If I use a -5cc 4.07 piston, then I need a larger gasket than 4.07. Closest seems to be a cometic 4.0865 x .036. That would put my compression close to 10.3-10.4. I'd have to mill the heads to 59cc just to get to 11.5. Quench would be around .045 w/ 59cc and assuming .01 above the deck. Advertised IVC would need to be > 72 to keep DCR near 8.6. How much to mill?

What else doesn't move over?

JimMueller

iTrader: (9)

I guess I could use the 4.065 piston instead of the 4.070, then use the GM LS3 headgasket. But the quench won't be as tight...?

KCS

iTrader: (20)

With a .036" thick gasket and the piston .010" above the deck, that's .026" quench. With that, you can probably kiss your motor goodbye.

By my calculations, you should get 11.6:1 with a GM LS3 headgasket, 59cc chambers, and the pistons .010" out of the hole, giving you roughly .041" for quench.

Swept=772.3cc
HG=10.9cc
Deck=-2.1cc
Piston=5cc
Chamber=59cc

Typically, every .005-.006" you mill is worth about a 1cc reduction in chamber volume.

JimMueller

iTrader: (9)

Dangit, math typo in a formula...you're right on the quench, so this is what I'm seeing now...

---Cometic gasket, 4.07 bore & 59cc chamber---
Chamber: 59cc
Gasket thickness: .036"
Gasket Bore: 4.085"
Deck clearance: +.01"
Stroke: 3.622"
Bore: 4.07"
Piston: 5cc dish
Rod length: 6.125
Advertised IVC: 72*

---GM LS3 gasket, 4.065 bore & 59cc chamber---
Chamber: 59cc
Gasket thickness: .051"
Gasket Bore: 4.065"
Deck clearance: +.01"
Stroke: 3.622"
Bore: 4.065"
Piston: 5cc dish
Rod length: 6.125
Advertised IVC: 72*

Somehow our SCR results don't match. In addition, to get from 69.8cc to 59cc requires I lose ~10cc, and at .006" per cc, I need would need to shave that stock head .060", which is a helluva lot. It seems the most people are willing to shave off these LS3 heads and maintain PTV clearance as well as parts alignmewnt is .030. PTV with the valve reliefs shouldn't be an issue. That means the most I can reduce the chamber to is (~70-(.030/.006))=65cc. With the LS3 gasket I now get 10.2 SCR, and with the .036 Cometic gasket. Assuming my numbers are right, I can't seem to find a nice combination of quench & SCR.

KCS

iTrader: (20)

I calculated the CR using a 4.07" piston, and a gasket bore of 4.08". According to GMPP, the GM LS3 gasket can accomodate a max bore of 4.08", so I'm assuming that's what the gasket is. Also, with the piston .010" out of the hole, it would protrude into the chamber volume, making it a negative number thus reducing volume, and not a positive, like the 5cc valve reliefs, which add volume.

So at 65cc for the chambers, I still get 10.8:1 CR, which isn't bad. This just might be that point of diminishing return, where getting higher CR will cost more and more, and return less and less. From here, you can look at different pistons, heads, or valves, mill the heads and manifold (which at even .030", still might require new pushrods), maybe even a cheap stroker crank, like the Callies LSc, but all you'll get in return is 1 point more CR, if that.