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The rods are bad. Hopefully a 5 thousandths bore will clean up the one bad cylinder. So I’ll be needing a complete LS7 rotating assembly. Any recommendations? Reasonable recomendstions?
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Not trying to be a smartass, but how much do those rods weigh? Titanium scrap price is around $6 a pound IIRC. Might be worth the time and effort to press the pistons off. That $150 purchase price is getting smaller all the time.
Good luck bee jay. Sounds like your fun has just started. The ls swap van be an adventure but hopefully well worth it. I went the crate motor ls3/525 route w/ a 4l70 transmission.
You can get a K1 crank and rods reasonably priced, and I feel their quality is better then the Compstar stuff. You can get a whole K1 rotating assembly (pistons, rods, crank) for about $2100.
Can you tell me who carries this K1 rotating assembly please? Thanks.
Bee Jay
More bad news. .005" will not clean up the bore. .020" may be needed. Does anyone make a .020" over piston for the LS7. Not ready to toss this engine off the pier yet.
Bee Jay
Can you tell me who carries this K1 rotating assembly please? Thanks.
Bee Jay
Unless they've changed, Don Hardy engines in Floydada, TX should carry them. The son is Donald and he does a ton of LS stuff, ask for him, they carried K1 stuff a year or so ago when I was there, I assume they still do.
Can you tell me who carries this K1 rotating assembly please? Thanks.
Bee Jay
Anyone sells K1. Summit, Jegs, any LS engine shops.
LME, H2 Racing Engines, pretty much anyone can get K1 stuff. It’s about the same cost as Callie’s Compstar stuff, but better quality. My 4” compstar crank needed a lot of work out of the box to get it right. Then it flexed itself to death and wiped out main bearings after 8k miles at 850 rwhp.
I wouldn’t bother trying to find LS7 stock rotators. You’ll pay top dollar for it and it’s not as good as real forged stuff.
On the block, I’m not sure an LS7 block will go .020”. The liners are already very thin to start with. If you do go .020, you can get Wiseco to make you a custom piston for whatever bore size you need. Remember you’ll need .005” for a hone job also. Try to keep the piston to cylinder clearance at .004-.005”.....too much more then that and it’ll drink oil.
I had a 6.0 iron block I had to hone out to .010”, and get a custom .006” over sized piston to true everything up and get the piston to wall tight at .004”. Pistons were about $800 if I recall and took a month to have them made.
I got some much needed motivation yesterday. Super Chevy magazine arrived with an LS7 powered C3. I can’t spend like this guy did, but I can do a decent LS7 conversion that should kick some autocross butt!
More bad news. The liners are cracked on the two cylinders with the bad rod bearings. So I have to take the block down to LA to have two cylinders re-sleeved.
Ugghh sorry to hear. I am not up to speed on LS platform surgery. I stick with old heavy metal big blocks. Seems like there sure is a great deal to learn. Thanks for posting the info. Sorry for your luck
Update. I took the block down to LA Sleeve. They kept it almost three months, but everyone said they were where to go. Only #5 had to be sleeved, they honed all eight to .005" over. The block has been cleaned and it's a good block now.
I ordered this kit from Custom Built Motors in LA. : https://www.ebay.com/itm/GM-LS7-ROTATING-ASSEMBLY-4-125-BORE-/231576847133
It has new forged Mahle pistons, and reconditioned LS7 Rods and Crank, and new bearings. I set the crank in the block today. I would have started putting the pistons in, but I can't get the damn circlips in the pistons. I'll need to drop off the pistons and rods off at an engine shop tomorrow. Torqueing the main bolts is different than my Small Block Chevy experience. You torque the bolts 15 ft lbs, then rotate the bolts another 80 degrees or 51 degrees for the outer bolts. There is nothing budget about building these LS engines. There is no "gasket kit" and head gaskets are $100. Oil pan gaskets, front cover gaskets, rear cover gaskets, top valley cover gaskets, are bought individually, and are expensive. I'm in no hurry, and building and engine is fun. So, I'll work on completing the engine over the winter, and maybe get the car into the C3 next summer. Accessories, accessory drive, conversion headers, motor mounts, dry sump tank, etc. etc. will all be very expensive. I'll also need a ignition controller and a LS7 intake manifold for carbs. But a 427 LS7 C3 will be fun, I hope.
Bee Jay
I scored an intake manifold off of eBay. GM 25534413. It’s about the same height as the RPM Airgap I’m running on the 383 now. I need to plug the fuel injection holes. Any ideas? I’m going to put my Holley Sniper Carb replacement FI on top of this.
Tap and die sets come with thread gauges. After you determine the threads order aluminum Allen plugs
a welding shop could make quick work of it
N2O injection because it is such a low hp 427 motor with only 505 hp
i only want to plug temporarily without altering the manifold. I may want to go with port injection later or sell the manifold if I go to an LS intake.
Whats up G Kool?
i only want to plug temporarily without altering the manifold. I may want to go with port injection later or sell the manifold if I go to an LS intake.
Whats up G Kool?
you might call summit tech support and find out if Russell or earl's brand has the specific plugs for your manifold
or go by an injection place and figure it out from junk injectors that they have laying around
I can't really say on a forum what I have been up to
i only want to plug temporarily without altering the manifold. I may want to go with port injection later or sell the manifold if I go to an LS intake.
Whats up G Kool?
I have a pretty much unlimited supply of wine corks for plugging those holes.
Measure the spacing between the fuel injector port and the fuel rail hold down bolt holes to see if they share common spacing. If they do, you could have some aluminum plugs made with an o-ring popped into place and held in place with a bolt. It would cost some machining time and some aluminum stock, but if they are all the same, it's only one program for the part. I'm not sure about the ability to withstand underhood heat, but 3D printed part might work for this application too.
Some things to consider. Might be easier to get a carb LS7 manifold, or run injectors and an air only throttle body. Are you keeping the GM dry sump? Or convert to a wet sump front cover- GM sells one that has a provision for a distributor and a Dailey oil pan and pump. Big $$$ but light years ahead of GM's damp sump. If you are keeping the stock LS& oil pan, add Improved Racing's windage tray and crank scraper. Stock tank? Add the Aviaid baffle or go with the better Peterson tank- 1/2 the price of GM's tank.
I've seen carb vs. EFI dyno comparisons where they just left the injectors in the manifold and disconnected the wiring.
You might be able to find a cheap set of injectors (flow rating won't matter) to "plug" the holes and then get some fuel rails and the correct hold down brackets.
This will also give you a head start on your port injection swap later on.
Good luck with the swap.
I'm anxious to see it again when it's done.
02-24-2018, 08:51 PM
because it is such a low hp 427 motor with only 505 hp
