brodix and trickflow have in my opinion,the best looking castings and machine work, and in most cases have excellent heads
almost all cylinder heads out of the box need to have minor port and bowl clean-up work, so careful dis-assembly and inspection and cleaning is always a very good idea.
do yourself a favor and read these links
viewtopic.php?f=52&t=534&p=1042&hilit=bare+assembled#p1042
viewtopic.php?f=50&t=248&p=295&hilit=bare+port#p295
dart,edelbrock and AFR all come in a close second
some of the other stuff looks like its slapped together by drunk monkeys
Id suggest sticking to those 5 brands, your choice will depend on each application, no one brand or one cylinder head design fits all applications well.
which of the 5 I use depends on the application but BRODIX,AFR,TRICKFLOW. DART,EDELBROCK, in roughly that order for SBC, and TRICKFLOW,BRODIX,DART,AFR,EDELBROCK in roughly that order for BBC I feel are the best value,..I.E. price for what you get, now don,t get crazy telling me about posted flow numbers, because a decent engine builder takes that into account before selecting the heads he will use for EACH application, and only a fool would think all applications require the same heads, or that some brands don,t have some heads that are better than others in some applications, flow numbers alone don,t determine the best heads
the ADVANTAGE in buying bare heads is in that you get to select each component and the clearances that are too be used in the assembly process. with no parts paid for then thrown away, its seldom cheaper because you tend to buy much better QUALITY parts and take a good deal more effort in checking the assembly and clearancing process.
off the shelf heads normally use far less expensive parts and have noticeably less care taken in the assembly process simply because they are assembled in large batches and the price rather than getting the most potential from those heads is a big factor.
you generally don,t get the best bee-hive springs , titanium retainers,light weight valves on off the shelf heads
READ THRU THESE
http://www.gofastnews.com/board/technic ... lumes.html
viewtopic.php?f=52&t=796
viewtopic.php?f=52&t=322
viewtopic.php?f=52&t=534
viewtopic.php?f=52&t=389
viewtopic.php?f=52&t=333
viewtopic.php?f=52&t=92
the question as to if assembled heads or buying bare heads and adding your selected components to match your application comes up frequently
that's a common question and the answer unfortunately is.. that the most effective route to building a quality engine ,is to buy the bare heads and cam kit with matched springs and let a experienced machine shop assemble the components and do the required machine work and clearance work, because it makes little sense to pay for springs,retainers and valves that you, discard,and won,t be using, if your planing on upgrading those components.
assembled heads generally provide a good start point for a generic engine build, but once you carefully check the components used by the manufacturer, and find they don,t match your requirements the assembled heads don,t look like as much like an attractive choice
its unfortunate because finding an experienced machine shop that does work at a reasonable cost and in a timely manor is not easy to do, in most areas,
and because you take a significant chance of getting your project totally screwed if your machine shop doesn,t do good work, plus the total cost tends to be higher than just slapping heads you get assembled onto an engine and installing a cam, and trusting to the manufacturers specs and LUCK that it will function as intended, simply because it takes a good deal of time and knowledge, and specific tools, to check all the clearances, spring heights,coil bind, valve guide clearance,etc.etc.
that's mostly because assembled heads are sold at a price point, and the manufacturer will not know which cam or engine combo it will be used with,so the manufacturer won,t be selecting the best valves,valve guides, retainers, and springs available, but a component that's a compromise between cost and quality to maintain both a decent quality product but a low total price.
and components that will work with a fairly broad range of engine combos, while keeping the price as low as he can to remain competitive in the market place.
while you can select better valves and springs and retainers that exactly match your needs.
threads with a good bit more related info, and useful sub links
viewtopic.php?f=52&t=534&p=1042&hilit=bare+assembled#p1042
viewtopic.php?f=52&t=2826&p=7296&hilit=bare+valves#p7296
viewtopic.php?f=52&t=181&p=2342&hilit=bare+valves#p2342
viewtopic.php?f=50&t=321&p=2931&hilit=track+notes+pad#p2931
viewtopic.php?f=52&t=401&p=698#p698
viewtopic.php?f=52&t=389&p=6855&hilit=shrouding#p6855
viewtopic.php?f=52&t=2630&hilit=shrouding
now IM not saying you can,t get a good deal on assembled heads because obviously in many cases the out of the box assembled heads from name brand manufacturers like AFR,BRODIX,DART,EDELBROCK,TRICKFLOW,etc. will provide good service, but if your serious about maximizing a heads potential it should be rather obvious that exactly matched components with the correct clearances, spring load rates, etc. that match your application,provide some benefits over a random collection of similar parts, machine work done, a generic valve spring,and clearance work.
now if your building a fairly generic 383 SBC with, 10:1 cpr and a dual plane intake designed to spin in the 3000rpm-6300rpm band, with a mid range hydraulic roller of flat tappet cam,for a basic hot street combo then by all means go with a basic 195cc-210cc head designed to match your components after checking the valve train,springs etc. against your requirements, because your very likely to find what you need in an off the shelf head,but if your building a 13:1 cpr roller engine your very unlikely to get the same performance from an assembled head as you could get from a properly prepped head and valve train with light weight valves and springs on a solid roller combo designed to hit 7000rpm plus
IF YOU HAVE A SET OF REALLY DEEP POCKETS
http://www.speierracingheads.com/SRH2.50.htm
http://www.airflowresearch.com/super-chevy-apr-2010-210cc-sbc.php
almost all cylinder heads out of the box need to have minor port and bowl clean-up work, so careful dis-assembly and inspection and cleaning is always a very good idea.
do yourself a favor and read these links
viewtopic.php?f=52&t=534&p=1042&hilit=bare+assembled#p1042
viewtopic.php?f=50&t=248&p=295&hilit=bare+port#p295
dart,edelbrock and AFR all come in a close second
some of the other stuff looks like its slapped together by drunk monkeys
Id suggest sticking to those 5 brands, your choice will depend on each application, no one brand or one cylinder head design fits all applications well.
which of the 5 I use depends on the application but BRODIX,AFR,TRICKFLOW. DART,EDELBROCK, in roughly that order for SBC, and TRICKFLOW,BRODIX,DART,AFR,EDELBROCK in roughly that order for BBC I feel are the best value,..I.E. price for what you get, now don,t get crazy telling me about posted flow numbers, because a decent engine builder takes that into account before selecting the heads he will use for EACH application, and only a fool would think all applications require the same heads, or that some brands don,t have some heads that are better than others in some applications, flow numbers alone don,t determine the best heads
the ADVANTAGE in buying bare heads is in that you get to select each component and the clearances that are too be used in the assembly process. with no parts paid for then thrown away, its seldom cheaper because you tend to buy much better QUALITY parts and take a good deal more effort in checking the assembly and clearancing process.
off the shelf heads normally use far less expensive parts and have noticeably less care taken in the assembly process simply because they are assembled in large batches and the price rather than getting the most potential from those heads is a big factor.
you generally don,t get the best bee-hive springs , titanium retainers,light weight valves on off the shelf heads
READ THRU THESE
http://www.gofastnews.com/board/technic ... lumes.html
viewtopic.php?f=52&t=796
viewtopic.php?f=52&t=322
viewtopic.php?f=52&t=534
viewtopic.php?f=52&t=389
viewtopic.php?f=52&t=333
viewtopic.php?f=52&t=92
the question as to if assembled heads or buying bare heads and adding your selected components to match your application comes up frequently
that's a common question and the answer unfortunately is.. that the most effective route to building a quality engine ,is to buy the bare heads and cam kit with matched springs and let a experienced machine shop assemble the components and do the required machine work and clearance work, because it makes little sense to pay for springs,retainers and valves that you, discard,and won,t be using, if your planing on upgrading those components.
assembled heads generally provide a good start point for a generic engine build, but once you carefully check the components used by the manufacturer, and find they don,t match your requirements the assembled heads don,t look like as much like an attractive choice
its unfortunate because finding an experienced machine shop that does work at a reasonable cost and in a timely manor is not easy to do, in most areas,
and because you take a significant chance of getting your project totally screwed if your machine shop doesn,t do good work, plus the total cost tends to be higher than just slapping heads you get assembled onto an engine and installing a cam, and trusting to the manufacturers specs and LUCK that it will function as intended, simply because it takes a good deal of time and knowledge, and specific tools, to check all the clearances, spring heights,coil bind, valve guide clearance,etc.etc.
that's mostly because assembled heads are sold at a price point, and the manufacturer will not know which cam or engine combo it will be used with,so the manufacturer won,t be selecting the best valves,valve guides, retainers, and springs available, but a component that's a compromise between cost and quality to maintain both a decent quality product but a low total price.
and components that will work with a fairly broad range of engine combos, while keeping the price as low as he can to remain competitive in the market place.
while you can select better valves and springs and retainers that exactly match your needs.
threads with a good bit more related info, and useful sub links
viewtopic.php?f=52&t=534&p=1042&hilit=bare+assembled#p1042
viewtopic.php?f=52&t=2826&p=7296&hilit=bare+valves#p7296
viewtopic.php?f=52&t=181&p=2342&hilit=bare+valves#p2342
viewtopic.php?f=50&t=321&p=2931&hilit=track+notes+pad#p2931
viewtopic.php?f=52&t=401&p=698#p698
viewtopic.php?f=52&t=389&p=6855&hilit=shrouding#p6855
viewtopic.php?f=52&t=2630&hilit=shrouding
now IM not saying you can,t get a good deal on assembled heads because obviously in many cases the out of the box assembled heads from name brand manufacturers like AFR,BRODIX,DART,EDELBROCK,TRICKFLOW,etc. will provide good service, but if your serious about maximizing a heads potential it should be rather obvious that exactly matched components with the correct clearances, spring load rates, etc. that match your application,provide some benefits over a random collection of similar parts, machine work done, a generic valve spring,and clearance work.
now if your building a fairly generic 383 SBC with, 10:1 cpr and a dual plane intake designed to spin in the 3000rpm-6300rpm band, with a mid range hydraulic roller of flat tappet cam,for a basic hot street combo then by all means go with a basic 195cc-210cc head designed to match your components after checking the valve train,springs etc. against your requirements, because your very likely to find what you need in an off the shelf head,but if your building a 13:1 cpr roller engine your very unlikely to get the same performance from an assembled head as you could get from a properly prepped head and valve train with light weight valves and springs on a solid roller combo designed to hit 7000rpm plus
IF YOU HAVE A SET OF REALLY DEEP POCKETS
http://www.speierracingheads.com/SRH2.50.htm
http://www.airflowresearch.com/super-chevy-apr-2010-210cc-sbc.php
Last edited by a moderator: