Top End Install Time
Melting Slicks
Joined: May 2007
Posts: 3,246
Likes: 4
From: Bay Area CA
With his pistons so far in the hole, could some one run a compression calc to see what his options are, as far as final compression, with the different head gaskets? It's needed info, at this point i think. 50 mills in the hole, flat tops with dual valve reliefs. 
According to this site: http://www.csgnetwork.com/compcalc.html#
every 25 mills in the hole, cost you 1/2 point in compression ratio, every 50- 1 point, aprx. With 10cc for the dishes, 4.10 in head gasket bore dia, 0.015 compressed thickness, 64 cc head chambers, 4x3.5 bore/stroke, and 50 mills in the hole, it gives 9.233:1. Perfect.
According to this site: http://www.csgnetwork.com/compcalc.html#
every 25 mills in the hole, cost you 1/2 point in compression ratio, every 50- 1 point, aprx. With 10cc for the dishes, 4.10 in head gasket bore dia, 0.015 compressed thickness, 64 cc head chambers, 4x3.5 bore/stroke, and 50 mills in the hole, it gives 9.233:1. Perfect.
Last edited by RunningMan373; Oct 3, 2009 at 01:46 AM.
Burning Brakes
Joined: Jul 2009
Posts: 1,132
Likes: 14
From: A town SC
The only way i can think of finding true CR is to bring the piston to TDC and run a light coat of vasaline around the gap between the piston and bore and CC the top of the piston,CC the head pick the gasket he will use (the cc spec will be on the package of a good gasket. do the math and wala......vic
Racer
Joined: Dec 2008
Posts: 300
Likes: 0
From: Toms River NJ
The pistons being .05 in the hole is more about his squish than this CR. I know its really about both, but if he's just doing the top end right now he can change his CR (mill heads, felpro 1094), he cant change his piston depth. Then again, if it was running ok before redoing the top end, it should run better afterwards, it just wont be optimal. sorry, just kinda talkin to myself out loud here. Just keep the piston depth in mind when you go to rebuild the bottom end, redman.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
Redman76, is showing 165 to 175 compression with 76cc factory heads
an obvious by looking at the picture .039 or .041 gasket with a volume
of 9.1cc, he is now going to switch to a 64cc chamber heads with
an .015 gasket with a volume of 3.2 cc. He will end up with plenty of compression for a 219 .050 hydraulic cam.
Now he has said hopefully in a yrs time he wants to build a 383 short block. Can you give me the reasoning behind tearing a short block all apart doing all this machining to gain a tad more compression in an engine he does not even want to keep. he has no oil control problems
compreesion shows good the engine in general looks to be in good shape.
an obvious by looking at the picture .039 or .041 gasket with a volume
of 9.1cc, he is now going to switch to a 64cc chamber heads with
an .015 gasket with a volume of 3.2 cc. He will end up with plenty of compression for a 219 .050 hydraulic cam.
Now he has said hopefully in a yrs time he wants to build a 383 short block. Can you give me the reasoning behind tearing a short block all apart doing all this machining to gain a tad more compression in an engine he does not even want to keep. he has no oil control problems
compreesion shows good the engine in general looks to be in good shape.
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
The pistons being .05 in the hole is more about his squish than this CR. I know its really about both, but if he's just doing the top end right now he can change his CR (mill heads, felpro 1094), he cant change his piston depth. Then again, if it was running ok before redoing the top end, it should run better afterwards, it just wont be optimal. sorry, just kinda talkin to myself out loud here. Just keep the piston depth in mind when you go to rebuild the bottom end, redman.
I was reading a thread where you were asking about gasket matching intake ports. How did that work out for you?
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
How critical are the head alignment dowels? When I pulled my old heads off, I was missing one. I tried to remove the other one when cleaning the block surface. I was having some problems getting out and stopped before I destroyed it. It has some marks on it now. Can I just file/sand to get rough edges off, or do I need to replace. I have already bought some Felpro replacement dowels to at least replace the missing one, but was curious about the other. If I need to remove . . . any tricks????
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
How critical are the head alignment dowels? When I pulled my old heads off, I was missing one. I tried to remove the other one when cleaning the block surface. I was having some problems getting out and stopped before I destroyed it. It has some marks on it now. Can I just file/sand to get rough edges off, or do I need to replace. I have already bought some Felpro replacement dowels to at least replace the missing one, but was curious about the other. If I need to remove . . . any tricks????
Last edited by Little Mouse; Oct 4, 2009 at 12:55 AM.
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Melting Slicks
Joined: May 2007
Posts: 3,246
Likes: 4
From: Bay Area CA
9.2:1 showed over 300 hp on a DD. Now, the stated stock C/R for a L48 with dishes is 8.5:1. Some engine builders say it's a false number, it's actually closer to 8.2:1. if the second number is correct, my set up is 9.2:1, which would make it dead on what Redman is building, with like parts. I would suspect like numbers,, ie: 320hp/400T. It will be a worthwhile build- as is, which i think is important. if it would have showed 8.0:1 or some such low number, pulling the block now, and building it probably would have been a better course. Your gonna be very happy with this build, might not see the need to upgrade. 
as a side note, i just installed full length headers on the 'Vette. The difference is great. Be sure to install full length headers on your build, Redman, if you don't already have them. i was hitting a wall at around 4k RPMs, engine really grumpy with all that back pressure. With headers, the engine sings up to the 5k rev limit i set on the MSD module, exhaust tone much smother and quieter, believe it or not. I got these cheapies, but hey, for 259 the fit perfect, and are ceramic coated
http://www.summitracing.com/parts/BIG-31106FLT/
as a side note, i just installed full length headers on the 'Vette. The difference is great. Be sure to install full length headers on your build, Redman, if you don't already have them. i was hitting a wall at around 4k RPMs, engine really grumpy with all that back pressure. With headers, the engine sings up to the 5k rev limit i set on the MSD module, exhaust tone much smother and quieter, believe it or not. I got these cheapies, but hey, for 259 the fit perfect, and are ceramic coated
http://www.summitracing.com/parts/BIG-31106FLT/
Last edited by RunningMan373; Oct 4, 2009 at 02:38 AM.
Racer
Joined: Dec 2008
Posts: 300
Likes: 0
From: Toms River NJ
What I got out of that thread was that if my intake manifold isnt absolutely perfectly shaped, i might as well sell the entire motor for scrap because its not worth building. not exactly helpful since I dont have $700 to lay down for a wilson cnc ported manifold. I reached a conclusion on my own, tho. All the negative effect of having a head port that is larger than the manifold port are going to be there whether the manifold is matched to the head or not. The size difference, regardless of the transition, will cause fuel to condense into droplets (to a certain extent), the air to slow down, etc. If the manifold isnt matched tho, there is added turbulence which only makes a not-optimal situation worse. So you might as well make the transition as smooth as possible. So I port matched my RPM Airgap, and I'm going to port match my Vic Jr. I havent had either of them on the motor yet, and they havent been on the motor previously, so I cant really give before and after scenarios (which would be a GREAT thread if someone made a couple trips to a dyno). Those are just my thoughts tho.
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
Thanks, I've got the Hooker side mount setup with STS baffles.
Sounds like you did a good job of reading between the varying opinions. I get so confused sorting through some of this stuff . . . 
What I got out of that thread was that if my intake manifold isnt absolutely perfectly shaped, i might as well sell the entire motor for scrap because its not worth building . . . If the manifold isnt matched tho, there is added turbulence which only makes a not-optimal situation worse.
Racer
Joined: Oct 2009
Posts: 374
Likes: 1
From: Forsyth Illinois
Lane.....glad that you got the parts so quickly,and you are happy w/them.If you wanna go the new header route....you know where I am.
Thank you for your purchase,and looking forward to seeing your build progress.
Kevin
Thank you for your purchase,and looking forward to seeing your build progress.
Kevin
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
Just a quick update . . . life has caught up to me (working on son's truck, water leak in house - repairing damage, hurt my back) and I have not been able to do as much as I hope, but here is where I'm at:
- Radiators painted and have all necessary parts to assemble radiator support.
- Block is prepped and ready to go. I replaced one missing head alignment dowel, painted some of the more visable areas of the block, and have chased all the threads in block.
I'll keep tinkering with cleaning/painting and start the assembly process soon.
- Radiators painted and have all necessary parts to assemble radiator support.
- Block is prepped and ready to go. I replaced one missing head alignment dowel, painted some of the more visable areas of the block, and have chased all the threads in block.
I'll keep tinkering with cleaning/painting and start the assembly process soon.
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
I have the radiator assembly painted and ready to drop back in. Also finished gasket matching intake to heads. I'm doing a fiberglass repair on the passenger fender well and then will be ready to shoot the engine bay and front crossmember with paint. Here are some pics of the radiator assembly:
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
Port matching went pretty good I thought. I bought a cutting bit for my die grinder and opened it up to the gasket edge; only went 1" deep; then sanded smooth. I don't know that I'll ever be able to tell the difference between matched or not, but I wanted to give it a try.
Dang it, barely work on the car this weekend. Seems like the closer I get to assembly, the more I see to do. The "while-I'm-at-it " will pay off once I get running again.
Dang it, barely work on the car this weekend. Seems like the closer I get to assembly, the more I see to do. The "while-I'm-at-it " will pay off once I get running again.
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
What????? It's only been two (more) months. 
I'm really getting close. Had a buddy help me get radiator and support in tonight. Heads are on, valvetrain adjusted, everything lubed and oiled and most cables, hoses, etc hooked up. Got some final work to do and then fire up. Probably next nice day I will be ready to break cam in. I'll post some progress pics tomorrow!!!
I'm really getting close. Had a buddy help me get radiator and support in tonight. Heads are on, valvetrain adjusted, everything lubed and oiled and most cables, hoses, etc hooked up. Got some final work to do and then fire up. Probably next nice day I will be ready to break cam in. I'll post some progress pics tomorrow!!!