Pondering a future combo for my C5.....even though I'm completely happy
with my 25,000 mile LS1....the needle is just never full enough.....
Already have LS 3 rods getting new bushings and Katech bolts
New 4.0195" DNJ hyper pistons w/pins/locks/1.2/1.5/2.5 rings/coated skirts
LQ 4 crank measured 3.618" stroke....currently STD/STD
I soon will need to purchase my new LS 2 block which will then be honed to
4.0215" for a final PTW clearance of .002"
These pistons measured 1.319" compression height....short I know but they
were both cheap and with the heat rejecting barrier coating on the tops....
they actually look really nice. They measured all the same diameter/weight.
The crank will be getting offset ground to 3.66" in order to put the pistons @
.007" OOTH
Final cubic inch displacement will be 372 CID and 11.7 compression ratio
with GM mls gaskets and 61.4 cc chambers. Will be using my rockers/covers/
oil pump/pan/pick-up etc. to save a few bucks.
I'm plenty uncertain as to how I'm gonna fit a cam in without cutting reliefs
in the pistons or exceeding 8.6-8.7 DCR. IIRC the actual IVC will need to be
in the 72-73 range to accomplish this.
I'm a fan of small cams mainly for the drivability and mileage...plus I'm way
past gettin' all moist over lopey stumble....did that **** for 25 years.
I'm sorta thinkin' 227/233 range with a 115 + 2 deg and an advertised dur.
of about 50-52 deg. more than .050" duration. I'm still thinkin' the PTV
clearance will be pretty close with most .600 ish lobe profiles...but I'm
miles away from crossing that bridge....suggestions and thoughts welcome
Heads will be my still never used TEA stg 1 243s w/hollows
Car will be getting a Monster #2 and new torque tube bushings @ swap time
Merely guessing on 36-42 lb injectors as the LS 6 intake and factory air
intake will remain for visual stock appearance....lame I know but that's how
I want it. Don't care what it makes for power cuz I just want it to run well
and out perform my current combo while running, acting, and driving like
stock.
Nothing fancy or schnazzy what so ever...just crisp, accurate machining and
a decently matched combo of parts to let the LS design shine.....

 

Experienced LS cam swappers....thoughts on this recommendation fitting withOUT needing to flycut......
Intake lobe is .360" 280/230/201/154/95....612" w/1.7 ratio
Exhaust lobe .352" 284/236/206/157/93....598" w/1.7 ratio
Lobe separation of 115 degrees + 3 = ICL of 112
3 degrees of overlap.....true IVC @ 72
projected DCR of 8.74
Unsure what the valvedrop measurement of my heads is since they were
milled .040"....couple thousandths from valvejob/valves ground....etc
I will measure for sure but would kinda hate to order a cam and then either
need to flycut or retard it after the fact.
I'm guessing my PTV to be @ .035"-.040" range
I'm certain Cam-Only guys would probably be fine with that but I'm
http://forums.corvetteforum.com/c6-t...tio-chart.html

 

New Update ***** will be a 368 inch LS2 *****
About a month ago I drove 820 miles round trip to the Detroit area to pickup a good used LS2 block for 500 bucks. Immediately dropped it and my DNJ hyper pistons at the machine shop for a final bore/hone size of 4.021"
These pistons have a shortened pin height I'm assuming to be LQ block compatible and rather than off set grinding the rod pins on the crank and running a .030" undersize bearing I opted to have the block decked to 9.225"
The 24x LQ4 crank is currently getting balanced sometime this week and my LS3 rods have been re bushed/sized for .0008" pin clearance; out fitted with the now discontinued Katech rod bolts, and the big ends have been slightly honed to just under max high limit. Pistons are on the rods and rings and bearings are in place. Ring end gaps checked in at .0145 primary and .0185" secondary. Rod bearing clearance checked in at .0018"-.002"
My main bearings are from a low mile LS3 Grand Sport engine and are IROX polymer coated. Made by Federal Mogul/Speed Pro for GM...pretty expensive but like new and free to me.
I sold my TEA stg ones to (King LT1) and picked up some Wagner Automotive Research CNC 799 castings for 900 bucks, then had my LS6 hollows and Lunati gold duals swapped over from my 241s. Plan on running GM .051" head gaskets and a projected 11.4 compression ratio as my chambers are right at 62 cc.
I ordered from TSP over this past winter, a new Comp cam 226/.605": 232/.575" 114 LS + 3 degrees....projected DCR will be 8.67
I plan to stay LS6 intake and unsure of injectors as my 28.8 will not be enough and I'm thinking 42 lbs. will still be more than I need.....perhaps some FAST 36's as I'm guessing power to be in the lower 420-430 range.
My trans is going to RPM and I'm still undecided about a clutch set up. I can get a new LS7 with flywheel for cheap but I really want a Monster...
Since I'm a technological dip **** I'll see if I can upload some photos for eye candy.........
I don't own a nice camera but I have a tablet...any pointers from you smarty pants..????

 

I like different engine combos, cool stuff AR!

 

Sounds like a fun combo!! Wrap the LS1 in bubble wrap and store it.

I would see what RPM recommends for a clutch. I thought the LS7 was heavy and adds rotational mass?

Pick up some 3800 supercharged (36lb @ 43psi injectors). Easy to tune! My IDC is 71% with them and they should be perfect for your setup too!

Btw I am loving those TEA's, the car pulls like a freight train!!

 

I'd actually like to put my LS1 into a Chevette..LOL..that would trip MF'rs out
RPM did suggest the LT1 twin disc but it is over a grand....
The thing that worries me about the 3800 injectors are getting 2 of them from a different engine and wouldn't they be closer to 44's at 58 psi ???
I could always have mine sized up a bit as I don't believe my power will be all that much beyond the 28.8 limits. Unless I'm guesstimating too conservative. Speed Inc.'s dyno is stingy so I highly doubt it'll even tickle 440

 

You can buy them flow matched from injector rehab. No they actually are 41.x lb @ 58psi.

 

 

 

Sorry guys about the picture quality....guess I'm just happy my dumb *** figured out how to attach pics....LOL
How do I go about changing the thread title since it was going to be a 372 and is now only 368 inches ????

 

I gotcha. How do you like the pistons?

Cool build, be sure to keep us all posted.

 

Thanks Kent
I think for an NA only app these pistons should work quite well
They look exactly like the LS3 slugs from my buddys GS engine as far as shape and skirt coating, top anodized looking barrier and all.
They all size virtually identical and weigh within 2 grams so they are consistant.
They also have the thinner 1.2/1.5/2.5 mm LS2 style ring pack as opposed to the LQ stuff that I believe to be 1.5/2.0/3.0 mm
The one and only knock on them is the pin height. At 1.319" they are short which is why I originally planned to offset grind the crank to bring them up but instead chose to deck the block. With the deck at 9.225"; I hope for them to pop out just a few thousandths and with the .051" GM gaskets the quench should still be mid 40s or so. I certainly don't need any more static compression with such a small camshaft.

 

Thanks for sharing that. They sound like a pretty nice budget piston.

 

Pistons/pins/locks/rings for 270 shipped from RA
they have standard/.020 (.5mm)/.030 (.75mm)/.040 (1.0mm)
Plenty E-bay ones look similar but are the LQ style rings and are like a hundred bucks more as well

 

Also would like to thank Squalor from Alabama for sending me the upper LS2 gear from his Pro Gear timing set. Got it in the mail today and I'll be sending my LS1 gear back his way as I had ordered a Pro Gear set when I was convinced that I was gonna run my 25K LS6 short block. At this point of the game I simply may as well add another 22 cubits of LS good ness..

 

Just need to clean the anti rust goop off this thing
Pretty decent piece for a hundred bucks
American made heat treated gears and media tumbled to remove microscopic burrs

 

I purchased my bare castings from Competition Products right here in Oshkosh, Wisconsin for 950 cash....they are NEW not re-furbs
I then had C & S Machine in Butler, WI mill .014" off them. I spoke to Mr. Wegner who said they only do an .011" clean up to get 64 cc after the cnc work. I'm guessing 62 chambers after a total of 25 thou material removal.
Also these are listed as needing 2.02/1.57 valves and again after speaking to Karl himself, he told me his seat work is set up for stock valves. C & S verified this statement when they assembled the heads using my LS6 hollow valves. The assembled versions from Comp. Products come with the slightly larger valves as that is what they stock.
Wegner from Markesan, WI has been big into LS stuff for many years and used to be a part of the ASA engine program. He still makes timing covers with front mount distributor drive kits and mechanical fuel pump mounts for the stock car world now crossing over to the LS engine platform.
Admittedly he said to me that he can't seem to get 300 cfm from the factory casting while leaving the bowl ramp in there, but that the swirl and tumble effects from it still seem to produce great power....so I guess till I hit a rear wheel dyno sometime this summer , I'll just have to hope and pray he's right......

 

Glad I could help ! I'll be folowing this thread, keep the pictures coming.

 

Picked up my re balanced LQ4 24x crank on Friday and proceeded to check
the main bearing clearances. With my free used GM bearings I ended up getting .0026"-.0029" . Obviously these would be fine in an iron block app but since this aluminum I ordered up a set of Speed Pro 152M1 mains. Found them for a hundred bucks shipped and hope to have by Tues.
I will pop them in and begin measuring to which I predict mid one thou. clearance in which case I'll either have to scotch brite the bearing shells to gain a few tenths or else mix/match half standards-half ones to get about .0018"-.0022" range ideally.

 

So my main bearings showed up today and I guess the IROX polymer coated GM bearings that I originally measured must be close to a one under due to the Teflon overlay. My clearances did tighten up a tad but not nearly as much as I had predicted. My new range is .0024"-.0026" so I think I'm gonna just run it.
My oil pressures should be fine as the rods are on the tight side at .0018".