AFR 195 heads installed...reflections and lessons learned ( a little long)
03-23-2003, 12:14 AM
#1
AFR 195 heads installed...reflections and lessons learned ( a little long)
First, let me say that I have not yet started the car. I realized after the parts store closed that I needed a 90 degree hose fitting and a vacuum plug. Tomorrow morning it should be up and running.
OK, the work was pretty straight forward. Tore it down yesterday after work. Started re-assembly about 1pm today. This included time to port match the intake to the heads (and gasket) and clean my headers up a little. This is an hour or two off the job if you don't opt to do this.
Some points of interest.
If you are using the stock heater hose fitting on the intake some fuel lines will interfere (Mr. Gasket hard line). This is why I need the 90 degree adapter.
If you are using the stock vacuum line fitting on an Edelbrock Performer RPM intake it will not clear a Speed Demon unless you run a spacer. If you run a spacer you won't clear the stock hood.
You can fit an Edelbrock RPM Air Gap intake with a Speed Demon carb under the stock 74 hood if you run a drop base and 2" air filter. I opted for an Xtreme K&N for more air flow with the short filter.
The stock '74 temp sensor is on the right passenger head. There are no provisions for this on the AFR heads. This sensor will plug into the other water port on the RPM air gap intake, and the electric lead will connect, even around big valve covers, if you bend the blade on the fitting a little bit. This actually looks pretty good because the outlet hose to the radiator hides the fitting a little bit.
The spark plugs appear to be a little bit lower in the head than stock heads. This makes the plugs easier to change, and gives more clearance for the spark plug boots than stock, but you may need to change your separators a little bit to make it look right.
The Haynes manual for '68-82 Corvette has a simple method for checking valve lash which only requires turning the engine over (360 degrees on the crank) once. Don't forget to turn it over once more when finished or your distributor will be in backwards when you install it.
You need to remove the headers to get to the lower head bolts. You can grease your aftermarket greaseable idler arm while the headers are off. I know this is true for a manual steering car with Hooker Super Comps. don't know if other setups make it impossible to grease this fitting with the headers on. It's also easy to change your oil filter with the headers off.
Stock length pushrods worked on my setup (undecked block, 1.6 Pro Magnum Roller Rockers, AFR 195 heads). They may work not for you, check the length. Don't re-use your stock pushrods with roller rockers. You need hardened pushrods with the AFR heads.
You have to torque the rocker studs. Read the instructions, I almost missed this step.
Flat-top pistons worked on my setup as far as piston to valve clearance. I haven't calculated compression ratio, but I have been getting Av Gas a few miles from the house for about 20 cents more per gallon than 93 octane, so it shouldn't matter.
The RPM Air gap ports required more material to be removed than I expected. It didn't take long, but consider doing this if you go with the 195 heads. Don't know about the 190 heads. According to AFR the biggest difference between the two is the port entrance size, where the 195s are setup for RPM type intakes, and Super Comp (1-3/4") headers.
If you port match, protect the surrounding area with duct tape or other tape to prevent unintended damage if the bit slips. Sears sells a couple good bits, and a 60-grit sanding drum works really well for finishing the cut. Takes off alot more material than I would have thought.
Use anti-seize on anything that threads into the heads or intake. Unless it's in the water jacket, then use thread sealant. AFR recommends ARP brand sealant, which is what I used. I also used the ARP sealant on ALL the head bolts. Many of them enter the water jacket, so they require it. Because of the difference in lubricity between moly lube and sealant I opted to use the sealant on all the bolts to ensure the pre-load on all the bolts was as close to equal as possible. This should help prevent blown head gaskets or warpage.
nickel based anit-seize is more compatible with stainless steel and aluminum than copper.
The valve cover mounting bosses appear to be slightly further apart on the AFR heads than stock. My GM Performance cast alumimum valve covers drag a little on the ARP valve cover mounting studs with the AFR heads...with the stock heads they slipped right on. Not a problem, just a note.
That's about all I can think of right now...I'll report out when I start and drive it, and post pics as well.
Jeff
OK, the work was pretty straight forward. Tore it down yesterday after work. Started re-assembly about 1pm today. This included time to port match the intake to the heads (and gasket) and clean my headers up a little. This is an hour or two off the job if you don't opt to do this.
Some points of interest.
If you are using the stock heater hose fitting on the intake some fuel lines will interfere (Mr. Gasket hard line). This is why I need the 90 degree adapter.
If you are using the stock vacuum line fitting on an Edelbrock Performer RPM intake it will not clear a Speed Demon unless you run a spacer. If you run a spacer you won't clear the stock hood.
You can fit an Edelbrock RPM Air Gap intake with a Speed Demon carb under the stock 74 hood if you run a drop base and 2" air filter. I opted for an Xtreme K&N for more air flow with the short filter.
The stock '74 temp sensor is on the right passenger head. There are no provisions for this on the AFR heads. This sensor will plug into the other water port on the RPM air gap intake, and the electric lead will connect, even around big valve covers, if you bend the blade on the fitting a little bit. This actually looks pretty good because the outlet hose to the radiator hides the fitting a little bit.
The spark plugs appear to be a little bit lower in the head than stock heads. This makes the plugs easier to change, and gives more clearance for the spark plug boots than stock, but you may need to change your separators a little bit to make it look right.
The Haynes manual for '68-82 Corvette has a simple method for checking valve lash which only requires turning the engine over (360 degrees on the crank) once. Don't forget to turn it over once more when finished or your distributor will be in backwards when you install it.
You need to remove the headers to get to the lower head bolts. You can grease your aftermarket greaseable idler arm while the headers are off. I know this is true for a manual steering car with Hooker Super Comps. don't know if other setups make it impossible to grease this fitting with the headers on. It's also easy to change your oil filter with the headers off.
Stock length pushrods worked on my setup (undecked block, 1.6 Pro Magnum Roller Rockers, AFR 195 heads). They may work not for you, check the length. Don't re-use your stock pushrods with roller rockers. You need hardened pushrods with the AFR heads.
You have to torque the rocker studs. Read the instructions, I almost missed this step.
Flat-top pistons worked on my setup as far as piston to valve clearance. I haven't calculated compression ratio, but I have been getting Av Gas a few miles from the house for about 20 cents more per gallon than 93 octane, so it shouldn't matter.
The RPM Air gap ports required more material to be removed than I expected. It didn't take long, but consider doing this if you go with the 195 heads. Don't know about the 190 heads. According to AFR the biggest difference between the two is the port entrance size, where the 195s are setup for RPM type intakes, and Super Comp (1-3/4") headers.
If you port match, protect the surrounding area with duct tape or other tape to prevent unintended damage if the bit slips. Sears sells a couple good bits, and a 60-grit sanding drum works really well for finishing the cut. Takes off alot more material than I would have thought.
Use anti-seize on anything that threads into the heads or intake. Unless it's in the water jacket, then use thread sealant. AFR recommends ARP brand sealant, which is what I used. I also used the ARP sealant on ALL the head bolts. Many of them enter the water jacket, so they require it. Because of the difference in lubricity between moly lube and sealant I opted to use the sealant on all the bolts to ensure the pre-load on all the bolts was as close to equal as possible. This should help prevent blown head gaskets or warpage.
nickel based anit-seize is more compatible with stainless steel and aluminum than copper.
The valve cover mounting bosses appear to be slightly further apart on the AFR heads than stock. My GM Performance cast alumimum valve covers drag a little on the ARP valve cover mounting studs with the AFR heads...with the stock heads they slipped right on. Not a problem, just a note.
That's about all I can think of right now...I'll report out when I start and drive it, and post pics as well.
Jeff
03-23-2003, 01:05 AM
#2
Melting Slicks
Re: AFR 195 heads installed...reflections and lessons learned (no_radio)
Sounds like a great project. Let us know how she runs.
03-23-2003, 01:19 AM
#3
Re: AFR 195 heads installed...reflections and lessons learned (74 vert)
Thanks for the info. It is all the little stuff that you listed that people can use in the future.
03-23-2003, 01:24 AM
#4
Drifting
Member Since: Mar 2001
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Re: AFR 195 heads installed...reflections and lessons learned (74 vert)
Sweet deal Jeff. I didn't know they'd be in so soon. Or maybe It's been longer than I thought since I've talked to you. If you don't mind, I'd kinda really LOVE to swing by tomorrow and see how everything is going. I'l give you a call tomorrow.
Damn, I think I've just as excited as you are. If I keep my call..looks like I'll be following your footsteps..just with a bigger cam or so (which you plan to do don't you?)
-Aaron
Damn, I think I've just as excited as you are. If I keep my call..looks like I'll be following your footsteps..just with a bigger cam or so (which you plan to do don't you?)
-Aaron
03-24-2003, 10:03 AM
#5
Re: AFR 195 heads installed...reflections and lessons learned (Aaron-74)
OK, everything is installed and I fired it up. Right away I could feel and hear a difference. Sounds like a completely different car, much meaner.
I am getting an occasional backfire through the carb at idle, and sometimes when as I rev it at tip-in. I think I have the spark plug gap too wide, or I may need to re-adjust the valves. timing seems OK, but I will double check it.
Aaron74 and I took it out for a little test drive...WOW! Lost a little bottom end but from 1500 RPM on up it's really pulling, and is noticeably stronger and more rev happy. Didn't rev it past about 4000 or so, needs a new master cylinder which should be in today.
One more note...I wound up plugging the ports on the water pump and intake where the heater hose used to be (see above note about lack of 90 degree fittings to clear fuel line). I called Stewart this morning, they said as long as I am using their bypass type thermostat (which is required with Stage II pumps) this is not a problem. The benefit seems to be that the car warms up more quickly now. Before I had a problem with the car not warming up for like 15 plus minutes, not a problem now. We'll see if it develops any overheating problems, but that would just be an excuse for electric fans.
I'll post again when I get things sorted a little more, but will be pretty busy with work this week.
Jeff
I am getting an occasional backfire through the carb at idle, and sometimes when as I rev it at tip-in. I think I have the spark plug gap too wide, or I may need to re-adjust the valves. timing seems OK, but I will double check it.
Aaron74 and I took it out for a little test drive...WOW! Lost a little bottom end but from 1500 RPM on up it's really pulling, and is noticeably stronger and more rev happy. Didn't rev it past about 4000 or so, needs a new master cylinder which should be in today.
One more note...I wound up plugging the ports on the water pump and intake where the heater hose used to be (see above note about lack of 90 degree fittings to clear fuel line). I called Stewart this morning, they said as long as I am using their bypass type thermostat (which is required with Stage II pumps) this is not a problem. The benefit seems to be that the car warms up more quickly now. Before I had a problem with the car not warming up for like 15 plus minutes, not a problem now. We'll see if it develops any overheating problems, but that would just be an excuse for electric fans.
I'll post again when I get things sorted a little more, but will be pretty busy with work this week.
Jeff
03-24-2003, 09:39 PM
#6
Re: AFR 195 heads installed...reflections and lessons learned (no_radio)
OK, sorted some things out this evening.
Rechecked my spark plug gap, which I set with the wrong tool. Most plugs were around .060", which is too much even for the MSD. I reset all to .045" which is what I ran before the upgrades.
Then check timing. ~10 degrees retarded at idle with vacuum advance...this explained ALOT. The distributor had rotated during one my hard runs. OK, retimed it and tightened the hold-down bolt this time.
The timing change got me back most, if not all, of the low-end power I thought I had lost, which was nice. Pulls nicely at any RPM.
Also, called Stewart Water Pumps...if you are running a bypass thermostat (required with Stage II water pumps) you don't have to connect the heater hose ports. So that solved the interference issue with the fuel line.
Took it out and ran a 4.8 second 0-60 (per my new GTech Competition Pro). Best before mods was 4.9, but I haven't touched the carb or timing curve. And the chambered exhaust absolutely screams...I can't believe it could be that restrictive with the amount of noise it makes. Would like to baseline open headers vs. the chambered and see the difference.
Hopefully some time to tune this weekend, too much work this week.
I'll keep ya posted.
Jeff
[Modified by no_radio, 8:41 PM 3/24/2003]
Rechecked my spark plug gap, which I set with the wrong tool. Most plugs were around .060", which is too much even for the MSD. I reset all to .045" which is what I ran before the upgrades.
Then check timing. ~10 degrees retarded at idle with vacuum advance...this explained ALOT. The distributor had rotated during one my hard runs. OK, retimed it and tightened the hold-down bolt this time.
The timing change got me back most, if not all, of the low-end power I thought I had lost, which was nice. Pulls nicely at any RPM.
Also, called Stewart Water Pumps...if you are running a bypass thermostat (required with Stage II water pumps) you don't have to connect the heater hose ports. So that solved the interference issue with the fuel line.
Took it out and ran a 4.8 second 0-60 (per my new GTech Competition Pro). Best before mods was 4.9, but I haven't touched the carb or timing curve. And the chambered exhaust absolutely screams...I can't believe it could be that restrictive with the amount of noise it makes. Would like to baseline open headers vs. the chambered and see the difference.
Hopefully some time to tune this weekend, too much work this week.
I'll keep ya posted.
Jeff
[Modified by no_radio, 8:41 PM 3/24/2003]
03-24-2003, 10:46 PM
#7
Team Owner
Re: AFR 195 heads installed...reflections and lessons learned (no_radio)
Sounds awesome Jeff. Which cam are you running?
And how much did the AFRs set you back? I'm debating those or Dart Pro1.
And how much did the AFRs set you back? I'm debating those or Dart Pro1.
03-24-2003, 11:42 PM
#8
Le Mans Master
Member Since: Oct 2002
Location: Las Vegas - Just stop perpetuating myths please.
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Re: AFR 195 heads installed...reflections and lessons learned (no_radio)
Now you really have our attention! :cheers: How's about some 1/4 times with that G-tech? And is your cam a secret? :confused:
03-25-2003, 08:32 AM
#9
Re: AFR 195 heads installed...reflections and lessons learned (cardo0)
No secret on the cam, just a Comp 268H (not XE) installed straight up, but Comp puts 4 degrees advance (I think) in most of their cams from the factory. Double roller timing chain...1.6 Pro Magnum Roller Rockers, Magnum hardened pushrods. Performer RPM Air Gap and Hooker Super Comp Headers, MSD billet distributor with 6AL, rev limited at 6000 RPM. I guess I need to update my web site to include all this stuff.
Haven't run a 1/4 yet because the rear master cylinder is leaking, no safe place to run a 1/4 and slow down with current brakes. Picked up a brand new Raybestos MC last night, but will be at a conference tomorrow and Thursday so it may be weekend before I can get it installed.
Also, I think the carb will need to be rejetted, but swapping jets and running the GTech again will confirm.
Jeff
Haven't run a 1/4 yet because the rear master cylinder is leaking, no safe place to run a 1/4 and slow down with current brakes. Picked up a brand new Raybestos MC last night, but will be at a conference tomorrow and Thursday so it may be weekend before I can get it installed.
Also, I think the carb will need to be rejetted, but swapping jets and running the GTech again will confirm.
Jeff
