Heads for an 85
Race Director
Joined: Jun 2004
Posts: 13,961
Likes: 707
From: WI
2.5" options? I had a local welder make mine since if I had bought something it would have needed welding on my header flanges anyways.
You could also put on an LT1 system, they are nice and sometimes given away.
Other places to buy systems:
http://www.corvettecentralexhaust.co...mance_dual.php dual exhaust for $250, I wouldn't pay $200 for those mufflers though.
http://www.allencorvetteexhaustsystems.com/ has systems
http://www.pypesexhaust.com/sys-vette2.html they were making one as well
You could also put on an LT1 system, they are nice and sometimes given away.
Other places to buy systems:
http://www.corvettecentralexhaust.co...mance_dual.php dual exhaust for $250, I wouldn't pay $200 for those mufflers though.
http://www.allencorvetteexhaustsystems.com/ has systems
http://www.pypesexhaust.com/sys-vette2.html they were making one as well
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
Would i get more performance out of this system
http://www.parts123.com/parts123/yb.dll?parta~partsort
or
this one
http://www.corvettepartscatalog.com/...oducts_id=7850
with these mufflers
http://www.corvettepartscatalog.com/...oducts_id=1349
http://www.parts123.com/parts123/yb.dll?parta~partsort
or
this one
http://www.corvettepartscatalog.com/...oducts_id=7850
with these mufflers
http://www.corvettepartscatalog.com/...oducts_id=1349
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
RE: your fastengineparts heads......looks like they are bare castings....in other words, you would have to purchase and install your own: valves (with seals), springs, spring retainers. By the way, MAM does carry front and rear 2-1/2" "Y" pipes (check online). You would have to add a straight pipe to replace the cat, or get a high flow cat. This year (85) has bolt in cats, not welded in.
Why don't we back up a minute....You are 17 and are looking at getting more performance from your 85. Tell us about YOUR mechanical ability. Have you ever pulled heads and replaced them...or worked on an engine before. Have tools, sockets, ratchet, open ends, torx sockets, torque wrench, timing light, volt meter...any type of manual for the car? How about your dad....does he have the experience in this area to help you?
Just to get to the heads, you need to disconnect the battery, drain the BLOCK, remove the plenum, runners, intake (disconnecting the fuel lines and electronics to the injectors), pull the distributor, disconnect the exhaust manifold. Not to mention you have to pull most of the things off the front of the engine, alt, air pump, power steering pump, move the air conditioning to one side. Remove the rocker arms and push rods....then finally pull the heads. You have to label everything marking exactly where the parts/bolts/wires /hoses/ sensors go. As an example, the torx bolts that hold the runners to the intake are different lengths and you need to know exactly which goes where. Don't think you can remember what went where. Take pictures and label the S**T out of everything. Your ability to do all these things will have a direct impact on your budget to add parts. No ability...
...and pay the man.
You can buy parts, but if you are not installing them yourself...then take the cost of the part and double it (or more) to have someone install your parts. Remember that not only do you have the base part, but gaskets, sealants, coolant and perhaps fasteners.
Take a look at Summit, they have some SBC 175cc Trick Flow heads $995.95 - $1149.95, Summits own brand cast iron for $649.00, Summit aluminum 170 cc heads for $879.95, Edelbrock heads for $1119 - $1173 and AFR 180cc for $1440.95.
Why don't we back up a minute....You are 17 and are looking at getting more performance from your 85. Tell us about YOUR mechanical ability. Have you ever pulled heads and replaced them...or worked on an engine before. Have tools, sockets, ratchet, open ends, torx sockets, torque wrench, timing light, volt meter...any type of manual for the car? How about your dad....does he have the experience in this area to help you?
Just to get to the heads, you need to disconnect the battery, drain the BLOCK, remove the plenum, runners, intake (disconnecting the fuel lines and electronics to the injectors), pull the distributor, disconnect the exhaust manifold. Not to mention you have to pull most of the things off the front of the engine, alt, air pump, power steering pump, move the air conditioning to one side. Remove the rocker arms and push rods....then finally pull the heads. You have to label everything marking exactly where the parts/bolts/wires /hoses/ sensors go. As an example, the torx bolts that hold the runners to the intake are different lengths and you need to know exactly which goes where. Don't think you can remember what went where. Take pictures and label the S**T out of everything. Your ability to do all these things will have a direct impact on your budget to add parts. No ability...
...and pay the man.You can buy parts, but if you are not installing them yourself...then take the cost of the part and double it (or more) to have someone install your parts. Remember that not only do you have the base part, but gaskets, sealants, coolant and perhaps fasteners.
Take a look at Summit, they have some SBC 175cc Trick Flow heads $995.95 - $1149.95, Summits own brand cast iron for $649.00, Summit aluminum 170 cc heads for $879.95, Edelbrock heads for $1119 - $1173 and AFR 180cc for $1440.95.
Last edited by John A. Marker; Jan 28, 2009 at 08:29 PM.
Pro
Joined: Mar 2008
Posts: 702
Likes: 0
RE: your fastengineparts heads......looks like they are bare castings....in other words, you would have to purchase and install your own: valves (with seals), springs, spring retainers. By the way, MAM does carry front and rear 2-1/2" "Y" pipes (check online). You would have to add a straight pipe to replace the cat, or get a high flow cat. This year (85) has bolt in cats, not welded in.
Why don't we back up a minute....You are 17 and are looking at getting more performance from your 85. Tell us about YOUR mechanical ability. Have you ever pulled heads and replaced them...or worked on an engine before. Have tools, sockets, ratchet, open ends, torx sockets, torque wrench, timing light, volt meter...any type of manual for the car? How about your dad....does he have the experience in this area to help you?
Just to get to the heads, you need to disconnect the battery, drain the BLOCK, remove the plenum, runners, intake (disconnecting the fuel lines and electronics to the injectors), pull the distributor, disconnect the exhaust manifold. Not to mention you have to pull most of the things off the front of the engine, alt, air pump, power steering pump, move the air conditioning to one side. Remove the rocker arms and push rods....then finally pull the heads. You have to label everything marking exactly where the parts/bolts/wires /hoses/ sensors go. As an example, the torx bolts that hold the runners to the intake are different lengths and you need to know exactly which goes where. Don't think you can remember what went where. Take pictures and label the S**T out of everything. Your ability to do all these things will have a direct impact on your budget to add parts. No ability......and pay the man.
You can buy parts, but if you are not installing them yourself...then take the cost of the part and double it (or more) to have someone install your parts. Remember that not only do you have the base part, but gaskets, sealants, coolant and perhaps fasteners.
Take a look at Summit, they have some SBC 175cc Trick Flow heads $995.95 - $1149.95, Summits own brand cast iron for $649.00, Summit aluminum 170 cc heads for $879.95, Edelbrock heads for $1119 - $1173 and AFR 180cc for $1440.95.
Why don't we back up a minute....You are 17 and are looking at getting more performance from your 85. Tell us about YOUR mechanical ability. Have you ever pulled heads and replaced them...or worked on an engine before. Have tools, sockets, ratchet, open ends, torx sockets, torque wrench, timing light, volt meter...any type of manual for the car? How about your dad....does he have the experience in this area to help you?
Just to get to the heads, you need to disconnect the battery, drain the BLOCK, remove the plenum, runners, intake (disconnecting the fuel lines and electronics to the injectors), pull the distributor, disconnect the exhaust manifold. Not to mention you have to pull most of the things off the front of the engine, alt, air pump, power steering pump, move the air conditioning to one side. Remove the rocker arms and push rods....then finally pull the heads. You have to label everything marking exactly where the parts/bolts/wires /hoses/ sensors go. As an example, the torx bolts that hold the runners to the intake are different lengths and you need to know exactly which goes where. Don't think you can remember what went where. Take pictures and label the S**T out of everything. Your ability to do all these things will have a direct impact on your budget to add parts. No ability...
...and pay the man.You can buy parts, but if you are not installing them yourself...then take the cost of the part and double it (or more) to have someone install your parts. Remember that not only do you have the base part, but gaskets, sealants, coolant and perhaps fasteners.
Take a look at Summit, they have some SBC 175cc Trick Flow heads $995.95 - $1149.95, Summits own brand cast iron for $649.00, Summit aluminum 170 cc heads for $879.95, Edelbrock heads for $1119 - $1173 and AFR 180cc for $1440.95.
and please don't take that the worng way... he's really looking out for you, making sure you know what you are getting into.
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
RE: your fastengineparts heads......looks like they are bare castings....in other words, you would have to purchase and install your own: valves (with seals), springs, spring retainers. By the way, MAM does carry front and rear 2-1/2" "Y" pipes (check online). You would have to add a straight pipe to replace the cat, or get a high flow cat. This year (85) has bolt in cats, not welded in.
Why don't we back up a minute....You are 17 and are looking at getting more performance from your 85. Tell us about YOUR mechanical ability. Have you ever pulled heads and replaced them...or worked on an engine before. Have tools, sockets, ratchet, open ends, torx sockets, torque wrench, timing light, volt meter...any type of manual for the car? How about your dad....does he have the experience in this area to help you?
Just to get to the heads, you need to disconnect the battery, drain the BLOCK, remove the plenum, runners, intake (disconnecting the fuel lines and electronics to the injectors), pull the distributor, disconnect the exhaust manifold. Not to mention you have to pull most of the things off the front of the engine, alt, air pump, power steering pump, move the air conditioning to one side. Remove the rocker arms and push rods....then finally pull the heads. You have to label everything marking exactly where the parts/bolts/wires /hoses/ sensors go. As an example, the torx bolts that hold the runners to the intake are different lengths and you need to know exactly which goes where. Don't think you can remember what went where. Take pictures and label the S**T out of everything. Your ability to do all these things will have a direct impact on your budget to add parts. No ability......and pay the man.
You can buy parts, but if you are not installing them yourself...then take the cost of the part and double it (or more) to have someone install your parts. Remember that not only do you have the base part, but gaskets, sealants, coolant and perhaps fasteners.
Take a look at Summit, they have some SBC 175cc Trick Flow heads $995.95 - $1149.95, Summits own brand cast iron for $649.00, Summit aluminum 170 cc heads for $879.95, Edelbrock heads for $1119 - $1173 and AFR 180cc for $1440.95.
Why don't we back up a minute....You are 17 and are looking at getting more performance from your 85. Tell us about YOUR mechanical ability. Have you ever pulled heads and replaced them...or worked on an engine before. Have tools, sockets, ratchet, open ends, torx sockets, torque wrench, timing light, volt meter...any type of manual for the car? How about your dad....does he have the experience in this area to help you?
Just to get to the heads, you need to disconnect the battery, drain the BLOCK, remove the plenum, runners, intake (disconnecting the fuel lines and electronics to the injectors), pull the distributor, disconnect the exhaust manifold. Not to mention you have to pull most of the things off the front of the engine, alt, air pump, power steering pump, move the air conditioning to one side. Remove the rocker arms and push rods....then finally pull the heads. You have to label everything marking exactly where the parts/bolts/wires /hoses/ sensors go. As an example, the torx bolts that hold the runners to the intake are different lengths and you need to know exactly which goes where. Don't think you can remember what went where. Take pictures and label the S**T out of everything. Your ability to do all these things will have a direct impact on your budget to add parts. No ability...
...and pay the man.You can buy parts, but if you are not installing them yourself...then take the cost of the part and double it (or more) to have someone install your parts. Remember that not only do you have the base part, but gaskets, sealants, coolant and perhaps fasteners.
Take a look at Summit, they have some SBC 175cc Trick Flow heads $995.95 - $1149.95, Summits own brand cast iron for $649.00, Summit aluminum 170 cc heads for $879.95, Edelbrock heads for $1119 - $1173 and AFR 180cc for $1440.95.
Me and my dad rebuilt two motors in the last 3 years. One was my dads 350 from his truck (1994) and the other was my grandmas 3.8 from here 97 lesabre. The 350 had a blown head gasket and my grandmas car had a cracked head. (shes got a lead foot)
We have a lot of tools at our house (2 tool boxes) my dad used to own a oil change place, but often times did "side jobs" for people, rebuilding motors and such. And thanks for watching out for me, thats why i love this place, other people would probably tell me to use elmers glue to fasten the heads to the block and say good luck.
Wouldn't summit 170's not show much improvement because i heard that the stock ones are around 165cc or does the 5cc really make a difference? I'm not very educated on the flow techniques of heads yet.
Last edited by Pwnage1337; Jan 29, 2009 at 08:11 AM.
Team Owner
Joined: Feb 2006
Posts: 24,460
Likes: 7
From: sw Ohio
I dont think you'll want those on your '85 if the bottom end is stock. 64cc is a big jump from the stock 76c. It will push your compression high enough so that you'll need to run premium, unless thats no biggie for you. You'll need a cam and intake designed to take full advantage of the heads you choose as well.
As far as exhaust goes i'd go with 3" dual pipes and have a local shop do it.
As far as exhaust goes i'd go with 3" dual pipes and have a local shop do it.
Last edited by Demonic85; Jan 29, 2009 at 08:44 AM.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
The size of the chamber affects compression. A smaller chamber will increase compression because it squeezes tighter. Target compression can vary based on your heads, block, goals, etc... Aluminum heads weight less and can handle higher compression (without detonation). Going to alum heads can allow for higher compression and less weight. Both equals more go power.
Intake runner is a measurement designed to help you understand how large the "hallway" from the intake to the valve is. Bigger hallways can create more flow, but the velocity of air in the hallway is also important. More flow with smaller hallway = better port velocity. If two heads flow the same, the set with smaller runners will probably feel more responsive. It's that port velocity that helps fill cylinders for efficient operation.
If you could find a 165cc runner that would flow 260cfm, you'd really have an AWESOME replacement for your stock heads. AFR gets this level of flow with 180cc heads. They probably flow the best for the smaller runner size, but cost more to get it. When you pay less, you get less flow for a given runner size. The ones you posted take 200cc to accomplish 260cfm. (Plus they might not really flow as advertised -- depending on casting variations.) That's why they aren't "as good".
Trickflow has a 175cc version that's milled to 56cc.*** They flow about 230-240ish. Your stockers are probably 180ish. I'm not familiar with conversion from iron to alum heads but, if you can go from a 65cc chamber iron, to 56cc alum, I'm guessing that raises your compression at least 1 pt. (Calculator can be found in this location. If you can improve head flow 50, 60, 70cfm.... that's quite a bit too. More flow + more compression = more power.
In general, 1cfm can make up to 2hp -- so that should help you understand the potential. A head with 20cfm more flow COULD develop another 40hp. Don't forget to compare all lifts too. The valve is NOT fully open during the entire intake stroke. Some of it's air must come during partial opening!!!
***Note: Most other heads come CAST in 65-74cc chamber volumes. They can be milled to smaller sizes for increase compression. Aluminum headed Corvettes run 58c chambers. But, their piston dish is probably different than yours.
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Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
with GREGGENN. Your 85 heads are only about 160 cc heads. They are cast iron. Almost anything you buy new today will outflow these heads. Depending on your goals, you way want to stay around the 9:1 compression to run regular gas.It looks like you have some experience (yourself and your dad) and the tools needed to tackle this job and others as you get into your car. Even with the experience you both have, if you do tackle this head swap remember to label each bolt, hose....everything. You will thank yourself at some point as you are putting things back together.
The information I emailed you has several links concerning heads. Check out the flow number for comparison. Try and buy the best flowing heads you can for the budget you have. Aluminum for the most part is better than cast iron. If you do have a problem with an aluminum head, you can often get it welded and machined and be back up and running. Not so with cast iron. Aluminum will warp easier when exposed to overheating.
Good luck on your quest for power....use it wisely.
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
So I'm looking for heads have a 65cc combustion chamber to keep compression the same, a 165/170/180cc intake runner, that flows about 250+ cfm and is made of aluminum? Any suggestions?
Race Director
Joined: Jun 2004
Posts: 13,961
Likes: 707
From: WI
I would look to reduce the chamber size, and raise the compression. This will gain HP and MPG but you'd probably need to use premium gas. The cost of that may be negated by the MPG gain. Have you thought of just putting on some good used 113 heads? The later year head would be an upgrade and you can get a pair for around $350. Remember to plan for new head bolts, intake gaskets, etc.
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
if i were taking the engine apart that much, i think i would just put in some really good heads. How much HP and TQ would i gain if i raised the compression? would it be that much more? and the car is going to be primarily street so i don't think i would want to run premium gas all the time, especially in summer lol.
Race Director
Joined: Jun 2004
Posts: 13,961
Likes: 707
From: WI
If you have an unlimited budget then buy the best heads there are. AFR would be fine. One point of compression can be around 10 HP. An engine is a matching piece for airflow. If you get super flowing heads they won't do much without a super flowing intake and cam to match. Plus you'll need the exhaust flow to keep up.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Drifting
Joined: Feb 1999
Posts: 1,772
Likes: 33
From: Bradenton Florida
The 85 Heads are probrably the worst thing on the car. About that same casting as a 305 chevy monte carlo from 1979. The piston on the other hand are forged. They are flattop with vlv reliefs(easy to bump up the compression).
Best head for the money is the AFR 180/190. That will wake up your 85!!!!(mild intake runner with great flow/Velocity)
The ultimate proven combo for a 85 vette is AFR190 heads, 219LPE cam and the superram. The convertor on the 85 is about a 20-2200 stall. So it will get by.... if needed.
Also the 85 Vette came with 24lb Bosch injectors. 86 up came with 22lb.
I did not read every post just glanced at a few.
Being a former 85 Vette owner and going from stock to fairly wild...I can add some input.
Best head for the money is the AFR 180/190. That will wake up your 85!!!!(mild intake runner with great flow/Velocity)
The ultimate proven combo for a 85 vette is AFR190 heads, 219LPE cam and the superram. The convertor on the 85 is about a 20-2200 stall. So it will get by.... if needed.
Also the 85 Vette came with 24lb Bosch injectors. 86 up came with 22lb.
I did not read every post just glanced at a few.
Being a former 85 Vette owner and going from stock to fairly wild...I can add some input.
Last edited by BOWTYE8; Jan 30, 2009 at 04:01 PM.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
The 85 Heads are probrably the worst thing on the car. About that same casting as a 305 chevy monte carlo from 1979. The piston on the other hand are forged. They are flattop with vlv reliefs(easy to bump up the compression).
Best head for the money is the AFR 180/190. That will wake up your 85!!!!(mild intake runner with great flow/Velocity)
The ultimate proven combo for a 85 vette is AFR190 heads, 219LPE cam and the superram. The convertor on the 85 is about a 20-2200 stall. So it will get by.... if needed.
Also the 85 Vette came with 24lb Bosch injectors. 86 up came with 22lb.
I did not read every post just glanced at a few.
Being a former 85 Vette owner and going from stock to failry wild...I can add some input.
Best head for the money is the AFR 180/190. That will wake up your 85!!!!(mild intake runner with great flow/Velocity)
The ultimate proven combo for a 85 vette is AFR190 heads, 219LPE cam and the superram. The convertor on the 85 is about a 20-2200 stall. So it will get by.... if needed.
Also the 85 Vette came with 24lb Bosch injectors. 86 up came with 22lb.
I did not read every post just glanced at a few.
Being a former 85 Vette owner and going from stock to failry wild...I can add some input.
And to boot the AFR's now will yield more power then the older 190's you used back years ago (you would think). I still do this day have never been in a C4 with the "popular" 383 combo, but I have always wanted 2.
Bowtye8 has been there, done that!
Drifting
Joined: Feb 2008
Posts: 1,267
Likes: 27
From: Texas
my 85 has been through completely
I kept the stock cam for mpg since this is my daily driver but did bump the compression up to 10.2ish with heads and new pistons.
cam got a lil love with 1.6 roller rockers as well.
But with the TPI intake completely stock its only a streetlight to streetlight car. It FALLS on its face at 4000rpm and no way around that.
But hitting peak Tq numbers at around 2000rpm is a fun feature
sry to thread jack but what grade fuel should I run with 10.2:1 compression?
Supporting Vendor
Joined: Sep 2007
Posts: 164
Likes: 36
if i were taking the engine apart that much, i think i would just put in some really good heads. How much HP and TQ would i gain if i raised the compression? would it be that much more? and the car is going to be primarily street so i don't think i would want to run premium gas all the time, especially in summer lol.
