LQ4somona

Alright, you guys asked for more info on what I am planning so here it is. The block will be a resleeved LS6 block with a 4.125" bore, I am thinking either a Lunati or Callies 4" stroke. I am leaning towards either Crower or Oliver connecting rods. These will be swinging a set of Arias pistons. Piston rings will be Child & Alberts ZGTS rings. I don't know what main bearings, rod bearings, or wrist pins I will run. A set of C5R heads will be used, after they have been ported and thermal coated. I want a solid roller camshaft, and will be using comp cams lifters, pushrods, valvesprings, titanium retainers and locks. Jesel shaft mount rockers will be used in the stock ratio. Accel DFI will be used to allow for custom programing. A pair of Garret turbos will be used. I want the engine to live at about 10 lbs of boost on the street, and up to about 25 on the track. Any imput on rod/piston combinations, camshaft suggestions would be greatly appreciated guys. Also does anyone know what intake the colonel is using? I think that set up would work well in a boost environment.

Classic

iTrader: (3)

With the C5R heads won't your compression be WAY to high to run that much boost? Colonel's motor is running something insane like 15:1 or something - its been awhile since I've checked that thread. I think you would be better off with 6.0 heads, but hell I'd like ot see it done. That will surely be one stout combo.

Classic

iTrader: (3)

That is a really stout setup. As long as you can lower the compression the flow of those heads will be amazing. Thats really interesting that you are setting it up for the one lap event. I am planning on entering the One Lap event down the road. I say go for it. I believe there is someone running a 4-link C5R setup on the board here with a blower, not a turbo I think. However I can't remember who that is at the moment.

ls1290

iTrader: (20)

There is no way you can lower the compression enough with C5R heads to run any boost. Using the biggest dish pistons of -24cc and a gasket of 0.072", the compression level will still be 12.3:1. :boom:

LQ4somona

Going with a shorter rod will help in lowering the compression. Hopefully enough to make this engine very feasable. Going with a 6.0' rod will open up a bit more space then running either a 6.125' rod, or the factory length 6.097' rod. By not allowing the pistons to come that far up in the sleeve it is like increasing the CC's of the combustion chamber.

Fenris Ulf

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by LQ4somona:
<strong> Going with a shorter rod will help in lowering the compression. Hopefully enough to make this engine very feasable. Going with a 6.0' rod will open up a bit more space then running either a 6.125' rod, or the factory length 6.097' rod. By not allowing the pistons to come that far up in the sleeve it is like increasing the CC's of the combustion chamber. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Isn't it a bad idea to run that much negative deckheight? I think LS6 heads might be a more feasable option, especially for road racing.

Pro Stock John

iTrader: (34)

Good luck and keep us posted.

I think running those heads creates a lot of problems for you with the rest of the parts, and I would go with a 64-70 cc head rather than a 38cc head but that's your call.

LQ4somona

By reducing the rod length I beleive this will cause a problem with the pistons wobbling in the cylinder bores, but to over come this problem, I will try to get pistons with longer skirts. This extra lenght will help in eliminating the problem of the wobble. I would consider a differnt set of heads, but I already have the heads sitting on the bench in the garage. I have been hassled a few times to get around to using them, especially by my buddy who has been trying to order a set through the horrible local dealership.

LQ4somona

I am thinking that with these heads I won't have an airflow issue, and I would be very cool to run them on the street. My math is rusty, but with a shorter 6" rod, I would be able to lower the compression into the 8.75-9 to 1 range, which is boost friendly. Alot of thermal coatings will be used, which should help. Engine will be used in a car that is being set up for the One Lap of America event. Hopefully everything will be done and sorted out for the 04 event. Tranny issues are something I really expect once the engine is assembled, but I have a few tricks up my sleeve. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

LQ4somona

Alright my math says that I would end up with a fairly low compression ratio.
Bore Size: 4.125"
Piston Size: 4.122"
Stroke: 4"
Deck Height: 0.39"
Piston Ring Land: 0.275"
Piston Dome/Dish: 0 cc
Head Gasket Bore: 4.135"
Head Gasket Height: 0.054"
Cylinder Head Volume: 38 cc
Cylinder Volume: 875.964 cc
Gasket Volume: 11.883 cc
Deck Volume: 85.407 cc
Total Volume: 1011.341 cc
Engine Displacement: 427.64 cid
Compression Ratio: 7.47:1 <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Is my math fairly correct? Or did I miss something here? <img border="0" alt="[bang head]" title="" src="graemlins/gr_banghead.gif" /> <img border="0" alt="[bang head]" title="" src="graemlins/gr_banghead.gif" />

torchedZ

Can a resleeved block hold up with that much boost? I would think a C5R block should be used in a TT application. Cheaper route would be a 408ci iron block, but doesn't sound as cool and adds ~80lbs.

<small>[ March 03, 2003, 09:00 PM: Message edited by: torchedZ ]</small>

1CAMWNDR

iTrader: (21)

I say that instead of the short rod / meganegative deck height problem, sell your C5R heads to your friend and buy some Stage III 6.0 heads with 2.08 intake and 1.60 exhaust valves and buy some more reasonable pistons and rods. You may make some extra $$$ from selling the C5R heads.
I am no professional engine builder; but C5R heads and boost sounds like a bad idea to me.
Oh, and a 427" motor with Stage III heads, a solid cam, and a pair of hair dryers will make more power than you can ever hook up. <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" />

LQ4somona

After going through some of the other posts about resleeved blocks, I am beginning to lean towards running the C5R block, simple because I wouldn't have to worry about dropping a sleeve. I want to use these heads on the engine mainly for the airflow, and for the coolness factor of having an oddball engine combination. I have a thing about doing stuff differnetly than everyone else, although it usually goes against conventional wisdom to do so. <img border="0" alt="[driving]" title="" src="graemlins/gr_driving3.gif" />

Louis

iTrader: (7)

Honestly, the NA C5R will have more than enough for the 1 lap. Imagine an unrestricted C5R at lemans. Another thing to think of- you have to run a street tire, an MXX3 is what it used to be, not sure what it is now. You will have a hard time getting traction with a Goodyear road raceslick, much less a treaded street tire.

Some things to think about <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

scottywheels

You are better off wit the c5r block and ls6 stage 3 heads. you dont need monster heads because you are forcing the air. I mean im running an F1 blower at 15 psi through stage 3 ls1 heads and making good power.

LQ4somona

Loooking at cars that have been successful in One Lap at the race weight that I will be running and talking with a number of people who have ran in the event, it is a agreed that to try for not only a class win, but the overall title a vechile will need to be making around 650 to 700 relaible rwhp. Your numbers are very impressive, but I think that I just need more juice. I am also considering building a big inch SB2.2, something that was suggested by a friend. I mean those engines run a 6500++ rpm for 400-600 miles in NASCAR, so it is another possiblity.

LQ4somona

Why is everyone so down on my plan to build this thing? I mean yes, it will cost more than using a normal set of LS6/LQ4 heads, but that's a burden I am willing to bear. And the deck height will only be .390" negative. Most engines run in the .260-.240 negitive range so my negative deck height isn't all that bad. <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />

scottywheels

With 16 psi and the F1 id be around 700 rwhp. However I am going through the T400 so I should be around 625-650 rwhp. That is with ls1 heads. On a stock cube motor. The car is making over 570rwhp with just 8 psi on the F1 so I would think the c5r heads are great to talk about but not worth it in your case.

<small>[ March 05, 2003, 10:04 AM: Message edited by: scott ws6 ]</small>

CHRISPY

You can really hog out those C5r heads, there is a lot of material there <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Also I think cost/convenience wise the ported LS6 makes more sense.

With Ls6 heads flowing around 315cfm good valve sizes, C5R block, twin turbos you could meet your power goals EASILY <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Boost is a totally different ballgame <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Cheers,
Chris

LQ4somona

What type of flow numbers can a guy get from a set of these heads once they are ported? Who has actually ported these heads? Once these heads are ported, and the combustion camber work done how much larger will the cambers be? roughly?