79 RX7 LS 5.3 Turbo. (8.93 @ 153mph)
#81
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I think that shorter 3.27" stroke crank of the 4.8 dramatically reduces the
piston speed (ft./sec) which aids longevity when using the factory hyper-
pistons. IMO the broken chain, bent PRs, and valves came after the wrist pin
literally pulled the bottom of the piston apart...after it crunches it into the
head the brittle alloy grenades and all hell breaks loose. Think about the psi
of torsional forces that are applied to the rod/pin/piston on directional
change when you're boosting 2 atmospheres. Hell those hard parts are see-
ing the combustion pressures of over 20:1 compression![EEK !!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_eek2.gif)
![EEK !!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_eek2.gif)
piston speed (ft./sec) which aids longevity when using the factory hyper-
pistons. IMO the broken chain, bent PRs, and valves came after the wrist pin
literally pulled the bottom of the piston apart...after it crunches it into the
head the brittle alloy grenades and all hell breaks loose. Think about the psi
of torsional forces that are applied to the rod/pin/piston on directional
change when you're boosting 2 atmospheres. Hell those hard parts are see-
ing the combustion pressures of over 20:1 compression
![EEK !!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_eek2.gif)
![EEK !!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_eek2.gif)
#82
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I love this setup. Its really cool and pretty cheap build really.
Think the timing chain was the problem for sure.
I know you are not turning the motor very fast but I've had a lifter get turned in the tray and cause problems there too. Check yours out.
I would get a double roller and a high flow oil pump this next round.
#83
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Thanks. Lifters all looked great. But with all the bent push rods i wont be using them again. Some sort of aftermarket chain will be used. If all goes as planned ill have an alum 5.3 with the 243 heads when i get back from vacation. I sold my ls1. Ill keep the 4.8 as a back up for now. Got some gas lines ran to my shop so ill have all winter to play with it.
#84
11 Second Club
iTrader: (2)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Katech sells that C5R single row chain which is beefier than the LS2 and
works with the factory gears. It's the same chain they used on the endurance
road racing stuff and reported zero failures. They also stock and sell that GM
discontinued plastic tensioner, but the block sometimes needs to be drilled
and tapped for it.
I'm surprised you didn't put your 4.8 crank and long rods into that LS1 block.
http://store.katechengines.com/c5-r-...chain-p30.aspx
http://store.katechengines.com/camsh...cket-p390.aspx
http://store.katechengines.com/dampe...-ls6-p260.aspx
works with the factory gears. It's the same chain they used on the endurance
road racing stuff and reported zero failures. They also stock and sell that GM
discontinued plastic tensioner, but the block sometimes needs to be drilled
and tapped for it.
I'm surprised you didn't put your 4.8 crank and long rods into that LS1 block.
http://store.katechengines.com/c5-r-...chain-p30.aspx
http://store.katechengines.com/camsh...cket-p390.aspx
http://store.katechengines.com/dampe...-ls6-p260.aspx
Last edited by A.R. Shale Targa; 12-04-2013 at 12:30 PM. Reason: links added
#85
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Katech sells that C5R single row chain which is beefier than the LS2 and
works with the factory gears. It's the same chain they used on the endurance
road racing stuff and reported zero failures. They also stock and sell that GM
discontinued plastic tensioner, but the block sometimes needs to be drilled
and tapped for it.
I'm surprised you didn't put your 4.8 crank and long rods into that LS1 block.
http://store.katechengines.com/c5-r-...chain-p30.aspx
http://store.katechengines.com/camsh...cket-p390.aspx
http://store.katechengines.com/dampe...-ls6-p260.aspx
works with the factory gears. It's the same chain they used on the endurance
road racing stuff and reported zero failures. They also stock and sell that GM
discontinued plastic tensioner, but the block sometimes needs to be drilled
and tapped for it.
I'm surprised you didn't put your 4.8 crank and long rods into that LS1 block.
http://store.katechengines.com/c5-r-...chain-p30.aspx
http://store.katechengines.com/camsh...cket-p390.aspx
http://store.katechengines.com/dampe...-ls6-p260.aspx
I'm sure any quality single chain will be fine. I don't rev the motors high enough to need a dual chain IMO. Once the line lock is installed I won't be reving the crap out of it in the burn out box either.
#87
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
The 2008 5.3 I picked up for $500 had a slight miss according to the previous owner. He said he hoped it was a coil pack but swapped out coil packs with daily driver and they all tested fine. He didn't trouble shoot any farther.
Looks like the #1 cyl was oiling up the plug or not firing for one reason or another. Pulled the motor all apart and didn't find anything horrible. I should have checked compression on that cyl but it's a little late now.
Other than that it looked great. Took all the DOD (Drive On Demand) junk off. Seems simple enough. All of the lifters were in great shape. Looks like the DOD is only on the inner cyls so faulty DOD can't gum up the #1 cyl.
Heres a good plug compared to the #1.
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5233_zps69f45033.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5232_zps8141e005.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5229_zps5d603b04.jpg)
Fancy 243 heads (aka "the good ones")
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5227_zps8fd60e36.jpg)
DOD junk (I'm eliminating all of this with a 2008 4.8 valley cover $28 new from GM)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5217_zps40a1e3fb.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5225_zps2788fbfc.jpg)
Looks like the #1 cyl was oiling up the plug or not firing for one reason or another. Pulled the motor all apart and didn't find anything horrible. I should have checked compression on that cyl but it's a little late now.
Other than that it looked great. Took all the DOD (Drive On Demand) junk off. Seems simple enough. All of the lifters were in great shape. Looks like the DOD is only on the inner cyls so faulty DOD can't gum up the #1 cyl.
Heres a good plug compared to the #1.
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5233_zps69f45033.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5232_zps8141e005.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5229_zps5d603b04.jpg)
Fancy 243 heads (aka "the good ones")
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5227_zps8fd60e36.jpg)
DOD junk (I'm eliminating all of this with a 2008 4.8 valley cover $28 new from GM)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5217_zps40a1e3fb.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5225_zps2788fbfc.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5226_zps40c4993e.jpg)
#88
TECH Junkie
iTrader: (28)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Are you going to pressure test the heads and see if the valves seal before slapping it all back together?
Might be worthwhile to put in a bigger intake valve ($120 in parts) if you are doing a valve job.
Getting another 85lbs+ off the front end with the alum block! Woot
Might be worthwhile to put in a bigger intake valve ($120 in parts) if you are doing a valve job.
Getting another 85lbs+ off the front end with the alum block! Woot
#89
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Yea im pretty stoked to try it out. Ill clean the heads up good and inspect them. Hand lap on the valves should tell me if they are sealing. Trying to do it all without any machine work. If i see anything "odd" ill take them in.
How much bigger did you go on the valves?
How much bigger did you go on the valves?
#90
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Got to play a little this weekend. The new heater works like a champ!
Cleaned up the 243's pretty good. May end up wetsanding them with some glass, the OEM finish was pretty rough. Did the same with the engine deck. I had always used the die-grinder with the plastic roloc pads to clean up the iron decks. I'm paranoid with the alum. block, so I went at it with razor blades, Keeping them at 90* to the deck surface and scraping the crap out of it. Seems to work pretty well, but there are lots of low spots with gasket material still in them.
Pulled my PAC 1218 springs off the old 317 heads and installed them on the new 243's. At the same time I checked all the valve seats. I went ahead and re-lapped most of the exhaust valves, though they all looked decent. Did both valves on my questionable #1 cylinder.
![](https://i17.photobucket.com/albums/b100/Hybridgnx/IMG_20140104_152735_zps9d3cfea9.jpg)
![](https://i17.photobucket.com/albums/b100/Hybridgnx/IMG_20140104_152757_zpsf841b154.jpg)
Also pulled a piston. Look at this bad boy compared to the old Gen 3 rods I was running!
![](https://i17.photobucket.com/albums/b100/Hybridgnx/IMG_20140105_183449_zpsb3f8caeb.jpg)
Bearings looked new, cylinder walls looked great. The top ring was about .022 and the bottom .024 ish. I dont' think I'll bother regapping these. Can't believe how much carbon and crap was in the ringlands. One down.... 7 to go.
![](https://i17.photobucket.com/albums/b100/Hybridgnx/IMG_20140105_191845_zpsf25f152b.jpg)
Cleaned up the 243's pretty good. May end up wetsanding them with some glass, the OEM finish was pretty rough. Did the same with the engine deck. I had always used the die-grinder with the plastic roloc pads to clean up the iron decks. I'm paranoid with the alum. block, so I went at it with razor blades, Keeping them at 90* to the deck surface and scraping the crap out of it. Seems to work pretty well, but there are lots of low spots with gasket material still in them.
Pulled my PAC 1218 springs off the old 317 heads and installed them on the new 243's. At the same time I checked all the valve seats. I went ahead and re-lapped most of the exhaust valves, though they all looked decent. Did both valves on my questionable #1 cylinder.
![](https://i17.photobucket.com/albums/b100/Hybridgnx/IMG_20140104_152735_zps9d3cfea9.jpg)
![](https://i17.photobucket.com/albums/b100/Hybridgnx/IMG_20140104_152757_zpsf841b154.jpg)
Also pulled a piston. Look at this bad boy compared to the old Gen 3 rods I was running!
![](https://i17.photobucket.com/albums/b100/Hybridgnx/IMG_20140105_183449_zpsb3f8caeb.jpg)
Bearings looked new, cylinder walls looked great. The top ring was about .022 and the bottom .024 ish. I dont' think I'll bother regapping these. Can't believe how much carbon and crap was in the ringlands. One down.... 7 to go.
![Sad](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_sad.gif)
![](https://i17.photobucket.com/albums/b100/Hybridgnx/IMG_20140105_191845_zpsf25f152b.jpg)
![](https://i17.photobucket.com/albums/b100/Hybridgnx/IMG_20140105_191855_zpsc0bfc17c.jpg)
Last edited by Forcefed86; 01-05-2014 at 10:09 PM.
#91
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Good chance this is your #1 cyl. problem...
#10-06-01-008I: Engine Oil Consumption on Aluminum Block/Iron Block Engines with Active Fuel Management (AFM) (Install AFM Oil Deflector and Clean Carbon from Cylinder and/or Install Updated Valve Cover) - (Feb 19, 2013)
Subject: Engine Oil Consumption on Aluminum Block/Iron Block Engines with Active Fuel Management (AFM) (Install AFM Oil Deflector and Clean Carbon from Cylinder and/or Install Updated Valve Cover)
Models: 2007-2011 Cadillac Escalade Models2007-2011 Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe2010-2011 Chevrolet Camaro2007-2011 GMC Sierra 1500, Sierra Denali, Yukon Models2008-2009 Pontiac G8 GTBuilt Prior to February 1, 2011 (Updated Valve Cover) and October 2010 (AFM Shield)Equipped with Any of the Following Engines:– Aluminum Block V8 Engine with Active Fuel Management (AFM) (RPOs L94, LZ1, L99, LC9, LH6, L76, L92, LFA (Hybrid)) – Iron Block V8 Engine with Active Fuel Management (AFM) (RPOs LMG, LY5)
Attention: This bulletin does not apply to the Buick Rainier, Chevrolet TrailBlazer and GMC Envoy equipped with LH6 due to a different design oil pan and AFM pressure relief valve. This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 10-06-01-008H (Section 06 – Engine/Propulsion System).
ConditionSome customers may comment about engine oil consumption of vehicles with higher mileage (approximately 48,000 to 64,000 km (30,000 to 40,000 mi) and a service engine soon light being on and/or rough running engine. Verify that the PCV system is functioning properly. If the customer understands that some oil consumption is normal and still feels the consumption level is excessive, more than 1 quart per 2000 to 3000 miles of driving, perform the service indicated in this bulletin. It is no longer necessary to have the customer return multiple times to have the usage verified.
CauseThis condition may be caused by two conditions. Oil pulled through the PCV system or oil spray that is discharged from the AFM pressure relief valve within the crankcase. Under most driving conditions and drive cycles, the discharged oil does not cause a problem. Under certain drive cycles (extended high engine speed operation), in combination with parts at the high end of their tolerance specification, the oil spray quantity may be more than usual, resulting in excessive deposit formation in the piston ring grooves, causing increased oil consumption and cracked or fouled spark plugs (#1 and/or #7). Refer to the latest version of Corporate Bulletin Number 12-06-01-001.
CorrectionAluminum or Cast Iron Block - Oil in Intake Manifold - Install Updated Valve Cover on All Models Built Prior to February 1, 2011 Note: If vehicle is built after this breakpoint, it should already be equipped with this updated valve cover.
#10-06-01-008I: Engine Oil Consumption on Aluminum Block/Iron Block Engines with Active Fuel Management (AFM) (Install AFM Oil Deflector and Clean Carbon from Cylinder and/or Install Updated Valve Cover) - (Feb 19, 2013)
Subject: Engine Oil Consumption on Aluminum Block/Iron Block Engines with Active Fuel Management (AFM) (Install AFM Oil Deflector and Clean Carbon from Cylinder and/or Install Updated Valve Cover)
Models: 2007-2011 Cadillac Escalade Models2007-2011 Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe2010-2011 Chevrolet Camaro2007-2011 GMC Sierra 1500, Sierra Denali, Yukon Models2008-2009 Pontiac G8 GTBuilt Prior to February 1, 2011 (Updated Valve Cover) and October 2010 (AFM Shield)Equipped with Any of the Following Engines:– Aluminum Block V8 Engine with Active Fuel Management (AFM) (RPOs L94, LZ1, L99, LC9, LH6, L76, L92, LFA (Hybrid)) – Iron Block V8 Engine with Active Fuel Management (AFM) (RPOs LMG, LY5)
Attention: This bulletin does not apply to the Buick Rainier, Chevrolet TrailBlazer and GMC Envoy equipped with LH6 due to a different design oil pan and AFM pressure relief valve. This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 10-06-01-008H (Section 06 – Engine/Propulsion System).
ConditionSome customers may comment about engine oil consumption of vehicles with higher mileage (approximately 48,000 to 64,000 km (30,000 to 40,000 mi) and a service engine soon light being on and/or rough running engine. Verify that the PCV system is functioning properly. If the customer understands that some oil consumption is normal and still feels the consumption level is excessive, more than 1 quart per 2000 to 3000 miles of driving, perform the service indicated in this bulletin. It is no longer necessary to have the customer return multiple times to have the usage verified.
CauseThis condition may be caused by two conditions. Oil pulled through the PCV system or oil spray that is discharged from the AFM pressure relief valve within the crankcase. Under most driving conditions and drive cycles, the discharged oil does not cause a problem. Under certain drive cycles (extended high engine speed operation), in combination with parts at the high end of their tolerance specification, the oil spray quantity may be more than usual, resulting in excessive deposit formation in the piston ring grooves, causing increased oil consumption and cracked or fouled spark plugs (#1 and/or #7). Refer to the latest version of Corporate Bulletin Number 12-06-01-001.
CorrectionAluminum or Cast Iron Block - Oil in Intake Manifold - Install Updated Valve Cover on All Models Built Prior to February 1, 2011 Note: If vehicle is built after this breakpoint, it should already be equipped with this updated valve cover.
#92
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Thanks, I hadn't read that. Looks like the AFM pressure relief is part of the new pan assy’s? I’ll be running a 98 F-body pan so I’m guessing I won’t have to worry about it? Also I cleaned up the plugs when I removed them and the #1 plug had a crack in the porcelain. That may of been the issue. None of the other plugs were cracked.
After a season of racing and a couple thousand street miles the piston I pulled from my old motor looked pretty good. Ring lands were clean, little carbon residue on the piston face and head. May throw on a water/meth kit just to keep things clean. I’ve got a kit or 2 just sitting around.
After a season of racing and a couple thousand street miles the piston I pulled from my old motor looked pretty good. Ring lands were clean, little carbon residue on the piston face and head. May throw on a water/meth kit just to keep things clean. I’ve got a kit or 2 just sitting around.
#98
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
so is it safe to assume all the rwd aluminum 5.3L engines are good to go?
I want 24x..so the L33 is probably better.
BTW, sorry for the hack. Great work and you know your stuff!
I want 24x..so the L33 is probably better.
BTW, sorry for the hack. Great work and you know your stuff!
#100
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Glad I checked the rings, 2 were as small as .018-.19 range. May have been fine, but tops are all at .022 now. Bottom were all at .024 to .025 so I didn't touch those.
Took a 9x4 sanding block and some 400 grit to the heads and block. You can actually see all the milling marks and low spots from the OEM machining. Never noticed those before! Probably ground them all away with roloc wheels. :beems:
Short block is done.
New cam installed.
Went with a Cloyes billet single roller this time around.
Ordered the cheap china head studs for $60
New OEM LS9 MLS haed gaskets
Hoping to have it ready to drop back in the car next weekend.
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5248_zpsc8d9b1f9.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5253_zps243501d4.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5276_zps9da29326.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5256_zpsb20a849e.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/enginemachinemarks_zpsa55080e3.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5238_zps484b437f.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5259_zpsbde2acd7.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5260_zpsa4751230.jpg)
Took a 9x4 sanding block and some 400 grit to the heads and block. You can actually see all the milling marks and low spots from the OEM machining. Never noticed those before! Probably ground them all away with roloc wheels. :beems:
Short block is done.
New cam installed.
Went with a Cloyes billet single roller this time around.
Ordered the cheap china head studs for $60
New OEM LS9 MLS haed gaskets
Hoping to have it ready to drop back in the car next weekend.
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5248_zpsc8d9b1f9.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5253_zps243501d4.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5276_zps9da29326.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5256_zpsb20a849e.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/enginemachinemarks_zpsa55080e3.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5238_zps484b437f.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5259_zpsbde2acd7.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5260_zpsa4751230.jpg)
![](http://i17.photobucket.com/albums/b100/Hybridgnx/79%20RX-7/IMG_5235_zps4c1733d9.jpg)
Last edited by Forcefed86; 01-13-2014 at 01:41 PM.