Summit Cylinder Heads

[nsuengineer06]

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Does anyone have experience with Summit brand cylinder heads? Specifically I am looking at a set of cast iron heads with 72cc combustion chambers, 2.02 intake/1.60 exhaust valves, 1.25" valve springs good to .520 lift and 165cc runners. Summit part number SUM-152123. The valves in these are bigger than the vortecs with only 5cc less on the intake runners. They will be going on a built & bored 327.

I have read a few times that the Summit brand parts are often good parts that Summit has just put their name on. I don't know who makes these, but the price is good and the flow SHOULD be what I'm looking for. Any comments, recommendations, experience?

[Gearhead dude]

I don't have any specific knowledge of these heads, but did you know that Summit Racing Equipment's parent company also owns TrickFlow?

[highperf4x4]

They are good quality heads. However that 72cc combustion chamber is a drag. I was going to ask you why you didn't go with the 64cc heads with the 2.02 intake valves but I just went to their site and they don't have them listed anymore. I was fixing to order a set myself for 299 each. Now I'm miffed!!!! I should have bought them sooner. The only 64cc heads they're showing now have the 1.94 valves. I'm gonna have to send them an email and find out what happened to the heads I wanted.

[nsuengineer06]

highperf4x4 if you get any info on that please let us know! I was wondering myself why they didn't offer the 64cc chambers on them cuz I'm sure they'd sell a lot more of those than the 72cc's. That's what I really wanted, but I figure if that's all I can get at that price I can just buy some domed pistons.. I'll have to check my clearances though.. don't want any boo boo's.. lol

[Tx Firefighter]

I've got them on my 327.

[jamesi20]

I got these a few years back and they are a good deal for the money.
http://www.summitracing.com/parts/WRL-011250-1/

and NO,they are not made in china as some have rumored them to be.still made in michigan.

[highperf4x4]

Originally Posted by Tx Firefighter

I've got them on my 327.

Did you get the 64cc with the 2.02 valves?

Originally Posted by nsuengineer06

highperf4x4 if you get any info on that please let us know! I was wondering myself why they didn't offer the 64cc chambers on them cuz I'm sure they'd sell a lot more of those than the 72cc's. That's what I really wanted, but I figure if that's all I can get at that price I can just buy some domed pistons.. I'll have to check my clearances though.. don't want any boo boo's.. lol

I sent them an inquiry about what happened to the 64cc/2.02 heads but they haven't responded yet. I'll let you know what they say when I hear from them. I hope they're not discontinued.

[jamesi20]

yes,64c.c.and 2.02 intakes. they have manley s.s.valves and when I got mine the runners were 220cc and now they are 200 but I doubt you would notice the difference in a street machine.

[highperf4x4]

Originally Posted by jamesi20

yes,64c.c.and 2.02 intakes. they have manley s.s.valves and when I got mine the runners were 220cc and now they are 200 but I doubt you would notice the difference in a street machine.

The heads I was looking at were Summit brand and they were less than 300.00 each assembled with valve springs that were good up to .500 lift.

[chevydog66]

I would try to get the 64cc chamber. The 72's are almost too big ya.

[westofb]

How about some patriot aluminum heads? These have the valve size you want, 64cc .
here is a link to them https://www.patriot-performance.com/...&cat=40&page=1

[lyrikz]

Originally Posted by westofb

How about some patriot aluminum heads? These have the valve size you want, 64cc .
here is a link to them https://www.patriot-performance.com/...&cat=40&page=1

I was goign to get those heads and 2 or 3 people talked me out of it.. Said i would have to send the head directly to the machine shop to get it checked over because there is issues with the casting... They actually said that i would have to do that with ANY aftermarket aluminum head. Thats why i went with the stock cast iron.....

Is any of that true, or were they just trying to sell me?

[joedoozer]

Don't get to bent out of shape about them being 72cc. 10;1 is the magic number for street use. If it is daily driver, and pump gas only. You will be glad you have the 72cc. A decent flat top piston with 2 valve reliefs and it should get you real close to 10:1, might even put you just over. Anything more than that and you end up running octane booster or mixing your fuel; 92 with some racing fuel. I didn't want to be hassled with that stuff on a daily driver. But it all depends on what you think is a hassle haha.

[highperf4x4]

Originally Posted by joedoozer

Don't get to bent out of shape about them being 72cc. 10;1 is the magic number for street use. If it is daily driver, and pump gas only. You will be glad you have the 72cc. A decent flat top piston with 2 valve reliefs and it should get you real close to 10:1, might even put you just over. Anything more than that and you end up running octane booster or mixing your fuel; 92 with some racing fuel. I didn't want to be hassled with that stuff on a daily driver. But it all depends on what you think is a hassle haha.

That's a negative. A flat-top piston with a standard .028" head gasket thickness and a 72cc combustion chamber is 8.75:1.......... if you drop to a .015" head gasket you can get 9.25:1 but then you run the risk of a blown head gasket the first time you overheat the engine.

[highperf4x4]

Originally Posted by westofb

How about some patriot aluminum heads? These have the valve size you want, 64cc .
here is a link to them https://www.patriot-performance.com/...&cat=40&page=1

That looks like an awesome deal but I've never seen a set of aluminum heads that cheap. They are cheaper than cast iron and that's a red flag.

Besides, people don't realize that the only advantage of an aluminum head is weight. A cast iron head will create slightly more power as it holds more heat in the combustion chamber. You're also alot less likely to damage a cast iron head.

[joedoozer]

Not quite sure how you come up with that. These pistons http://www.summitracing.com/parts/TRW-L2491NF30/ with a 72 cc head, and an 028 head gasket comes in around 9.5:1 according to my calcs. PHV is 3.40cc's so technically i guess its not a flat top, although the piston is "flat" on top. Scratching my head on why the compression distance is so small though.

[chevydog66]

Dart Heads are the best. I have 2 sets. Best aluminum used. Aluminum heads are more forgiving around the 11:1 comp. mark. Here's a bunch of info about the Patriot heads http://www.chevelles.com/forums/show...t=patriot+head

[highperf4x4]

Originally Posted by joedoozer

Not quite sure how you come up with that. These pistons http://www.summitracing.com/parts/TRW-L2491NF30/ with a 72 cc head, and an 028 head gasket comes in around 9.5:1 according to my calcs. PHV is 3.40cc's so technically i guess its not a flat top, although the piston is "flat" on top. Scratching my head on why the compression distance is so small though.

Actually you may be right. I might be thinking of a 76cc head like the stockers.

As for those pistons, the specs seem a little off to me.

[joedoozer]

They might be for 6 inch rods, now that I think about it. I cant find the ones for the 5.7's. But the rest of the piston is the same haha. Coming in at 9.5 or maybe even 9.75:1 should be real good for 92 octane.

These kinds of threads are great when you are trying to put an engine together, and picking parts. A lot of ideas and info in one spot. Here is a really good website for engine combos, although I think some of the HP numbers are a little exaggerated.

http://www.ryanscarpage.50megs.com/combos1.html

Another edit . I found the pistons I am using with the 72cc heads.
http://www.summitracing.com/parts/STL-H631CP/
These have the correct compression height.