AFR Heads Arrived- Quick Question
Thread Starter
Race Director
Joined: Dec 1999
Posts: 11,096
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From: Sierra Foothills CA
AFR Heads Arrived- Quick Question
I took delivery of the AFR 195s that I ordered about 6-7 weeks ago- real pretty! They're not for my Vette though cuz I think I'd have trouble bolting em onto my bigblock ;) They're for the 355 in my 70 Z28. I had the local head guru set em up w/ better valves & check tolerances on seats- they checked out fine.
I don't really want to disassemble everything to re-torque the heads after start-up. He told me that when assembling it's acceptable to torque them once, wait an hour, back off the bolts & re-torque, wait another hour, & repeat the process one more time. Has anybody done it that way and, if so, did you have any problems with sealing? I fully intend to do it that way since he's so well respected but I'm just curious to hear from anyone who's done it that way. Thanks. :cheers:
I don't really want to disassemble everything to re-torque the heads after start-up. He told me that when assembling it's acceptable to torque them once, wait an hour, back off the bolts & re-torque, wait another hour, & repeat the process one more time. Has anybody done it that way and, if so, did you have any problems with sealing? I fully intend to do it that way since he's so well respected but I'm just curious to hear from anyone who's done it that way. Thanks. :cheers:
Melting Slicks
Joined: Jun 2003
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From: A high school diploma fixing what a college degree broke TN
St. Jude Donor '03 thru '26
Re: AFR Heads Arrived- Quick Question (Les)
I dont understand how that method accounts for the expansion and contraction of the block/heads after starting up and cooling down? I have seen a similar method used on aircraft,but not anywhere there would be a heat buildup.Just my opinion,but to be on the safe side,I would re torque after running. :cheers:
Thread Starter
Race Director
Joined: Dec 1999
Posts: 11,096
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From: Sierra Foothills CA
Re: AFR Heads Arrived- Quick Question (comp)
:iagree: with LT1
Drifting
Joined: Oct 2000
Posts: 1,825
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From: Shawano WI
Re: AFR Heads Arrived- Quick Question (Les)
If you use a good quality head gasket, such as a Fel-pro 1003, then no retorque is required. Fel-pro actually recommends that you do not retorque their Perma-Torque line of gaskets. I have not retorqued a head in over 10 years and have not had a head gasket failure in that time span either.
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Drifting
Joined: Jun 2000
Posts: 1,955
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Re: AFR Heads Arrived- Quick Question (Pete79L82)
I didn't retorque my AFR195 heads, which were installed with FelPro (I think PermaTorque, whatever AFR recommended on their web site) head gaskets last January. Approximately 1000 miles plus 35 trips down the 1/8 mile and no problems whatsoever.
Jeff
Jeff
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: AFR Heads Arrived- Quick Question (no_radio)
Les - on all my aluminum head rebuilds I set the TQ value and then I drive it for about one week to do some settle in from heat cycles. Then I retorq them all.
I'm also using .020 copper head gaskets. Years ago I had a slight leak on the outboard head to block and ever since then I retorq. Once.
I'm also using ARP head studs instead of bolts.
I'm also using .020 copper head gaskets. Years ago I had a slight leak on the outboard head to block and ever since then I retorq. Once.
I'm also using ARP head studs instead of bolts.
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
Re: AFR Heads Arrived- Quick Question (Les)
Well, I'm happy with mine..but I had a rocker stud break on me last night (solid roller). Its poly lock bound up the one beside it and bent a pushrod, broke the lifter body, beat the valve up, and ruined the roller.
If i was you i'd replace their junk rocker studs.
Also, if you want to do a little grinding/porting you can get a fair amount extra out of them...
:cheers:
If i was you i'd replace their junk rocker studs.
Also, if you want to do a little grinding/porting you can get a fair amount extra out of them...
:cheers:
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: AFR Heads Arrived- Quick Question (VETDRMS)
VETDRMS - When you have big springs and cam it causes rocker stud deflection. If you place a straight edge along your studs and if any of them deflect over .030 when the valve is fully open you need a stud girdle.
I've owned three different kinds of stud girdles and this Crane cams is one of the better units on the market.
I've owned three different kinds of stud girdles and this Crane cams is one of the better units on the market.
Race Director
Joined: Dec 1999
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Re: AFR Heads Arrived- Quick Question (gkull)
VETDRMS, what do you mean? Just stick a grinder in there and start porting? I would not recommend this, most likely your head will flow less afterwards. porting is more of an art than a science, it takes years of practise to get the feel for what is right and what is not, combined with extensive flow bench testing. just attacking the walls with your grinder is a big NO.
The only heads you can do that with are stock heads or any other head that has terrible casting glash, large valve guide bosses and big ridges behind the seat. You can easily clean those thins up without the chance of messing it up, however that's not real porting. Porting is when you change the shape, volume and characteristics fo the port to get a gain in airflow.
The only heads you can do that with are stock heads or any other head that has terrible casting glash, large valve guide bosses and big ridges behind the seat. You can easily clean those thins up without the chance of messing it up, however that's not real porting. Porting is when you change the shape, volume and characteristics fo the port to get a gain in airflow.
Drifting
Joined: Jun 2000
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Re: AFR Heads Arrived- Quick Question (VETDRMS)
Also, if you want to do a little grinding/porting you can get a fair amount extra out of them...
Jeff
Melting Slicks
Joined: Dec 2001
Posts: 2,025
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From: Billings MT
Re: AFR Heads Arrived- Quick Question (Twin_Turbo)
Wow, a touchy subject that's for sure. Sorry if I was misleading, I wasn't implying he should attack them with a grinder. I was implying that someone who knows what they are doing can make an improvement without taking a horrendous amount of time in the process. The fact is the CNC work on the street heads isn't that great. Its primary benefit is having equal sized runners/chambers. Due to casting artifacts even the CNC program doesn't accomplish this, although it is very close. There are some "left-overs" in the CNC program that can be removed and "cleaned up."
Sooo, without going into a huge debate. Bolt them on and have fun, I'm sure it will run great.
:cheers:
Sooo, without going into a huge debate. Bolt them on and have fun, I'm sure it will run great.
:cheers:
Race Director
Joined: Mar 2001
Posts: 11,322
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From: Living in the Hartland
Re: AFR Heads Arrived- Quick Question (VETDRMS)
I bought CNC ported Trick Flow heads and the main gain was on the exh side but was noticable throught the lift range for both. Was def worth the $150 for the flow gains for someone who would have to pay to have them ported.
Race Director
Joined: Dec 1999
Posts: 16,945
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Re: AFR Heads Arrived- Quick Question (VETDRMS)
Wow, a touchy subject that's for sure. Sorry if I was misleading, I wasn't implying he should attack them with a grinder. I was implying that someone who knows what they are doing can make an improvement without taking a horrendous amount of time in the process. The fact is the CNC work on the street heads isn't that great. Its primary benefit is having equal sized runners/chambers. Due to casting artifacts even the CNC program doesn't accomplish this, although it is very close. There are some "left-overs" in the CNC program that can be removed and "cleaned up."
Sooo, without going into a huge debate. Bolt them on and have fun, I'm sure it will run great.
:cheers:
Sooo, without going into a huge debate. Bolt them on and have fun, I'm sure it will run great.
:cheers:
Le Mans Master
Joined: Apr 2000
Posts: 7,562
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From: B'Ville NY
Cruise-In III Veteran
St. Jude Donor '05
Re: AFR Heads Arrived- Quick Question (Twin_Turbo)
Is re-torquing(sp?) something that commonly done with aluminum heads ? On my 350 with the iron Sportman II's I have never had to touch anything on it :confused: The engine shop hasn't said anything to me about retorquing the new engine's heads (AFR's) but I know the felpro head gaskets they installed weren't cheap either at $72.
