Cylinder Head Runner Size Selection - Summit Racing Quick Flicks

[@SummitRacing]

The other consideration should be intake runner size. 305 cid engines like a smaller runner due to the lack of bore size/cid and going to a larger runner 350 cid head will likely hurt low end torque production on your 305.

[@SummitRacing]

As long as the heads have a 1.94" intake valve or smaller most SBC 350 heads will work on your 305. The problem with using a 350 head though is that they typically have a much larger combustion chamber than a 305 head causing the compression to go down considerably. When making this change it is typically best to stick with a head that has a combustion chamber between 54 - 58 cc's to keep the compression up.

[@darrellsomers5427]

Doesn't it have to be fly cut to use a 4 inch bore head on a 283 or a 305 so the valves don't hit the block ?

[@m.pietro9087]

You should have an app for this selection.

[@HighPriest1776]

You recommend a smaller runner head for a 350 with 175-180 cc range to keep air flow up. I have a 305 so the difference would be about 157 cc and I’m having trouble finding heads like that for a sbc 305.

[@gabrielbryant892]

I am build a high compression 283 bored 30 over .it has trw pistons 12 to 1 .....the old 283 engines had flattop 10 to 1 with 58 cc power pack heads .I am wondering what I should get maybe 60 cc to slightly lower that compression .not sure what to do

[@rodneymartin2046]

Question. 1985 Chevy Corvette 383 stroker w/ 11.15:1 what cc runners should I be looking at. Street/Race. I want to keep my TPI.

[@robertog4351]

What about a 406 with a nice street cam ? What valve size 202 or 208? Over or under 200cc?

[@SummitRacing]

When choosing the proper cylinder head for any application there is far more to it than the compression ratio or which one tested as having more power. Cylinder heads should be chosen to fit the total package so, give us a call on the tech line and we will be happy to help you chose! 1-330-630-0240. Thanks for watching!

[@briandcarey3110]

I was thinking about about afr 195's, compression 10 to 1 , I got the retrofit thumpr cam a little over .500 on both sides plus 1.6 full roller rockers wich adds 30 points to the cam, some ppl say go with the 180's but I like the idea of switching to a bigger cam later on, it's a street car for now I want it to have good street maners, should I go with the 180's? It's a 383 stroker no forged internals

[@SummitRacing]

AFR is a quality cylinder head with good velocity. The 195cc intake runner has been a proven winner in many 383 combinations. Unless your vehicle is very heavy, the 195 Eliminators (or the 195 Enforcer if you're on a tight budget) would be my preference and give you room to grow. You will need a minimum stall speed of 2500 rpm and numerically higher gears with that camshaft to take full advantage of the combination.

[@rossgirdeen3247]

So a 175 cc intake runner to big for a 302

[@duramax78]

I have a lq4 and am gonna put at least 600hp to the flywheel, 6.0 litre how many cc approximately.?

[@SummitRacing]

Hi Ranjit, We would need to know camshaft specs and piston specs at least. Please give us a call at 1-800-230-3030.

[@paulthompson1654]

MCSA minimum cross section area =pushrod pinch . Cyl heads with inline valves ford windsor ,, chevy sb,, some Buick some Chrysler chev 400cu 220cc 2.2 sq inches ford 408 200cc 2.15 sq inches cc intake runner is for retail purposes ONLY engine builders use MCSA

[@infamousnova]

get the trickflow heads that are desgined for smaller bores

[@nikfish1]

How would increasing compression ratio effect low end torque and high end torque. Are there any advantages to lower compression, and if not then why do most companies offer heads with bigger chamber dimensions? Thank you

[@SummitRacing]

+Gas'n'Oil , Increasing compression ratio does increase torque output throughout the RPM range but, depending on fuel & ignition type, you run a greater risk of detonation. That’s bad for emissions and potentially detrimental to your motor!

[@donrutter6765]

A good article to read is a 2006 Hot Rod article by David Vizard called " Compression comprehension". The most effecient engine design runs at 200 psi of compression, whether its a 9:1 motor or a 14:1 motor. You choose the right duration cam to achieve the 200 psi.

[@duramax78]

Don Rutter David vizard is a genius.

[@75msmyra]

I have a 406ci flat top pistons and a pro comp mutha thumper camshaft what heads should I buy from summit ? 64cc combustion chambers or 72cc chambers ? I don't want detanation issues I wish your summit 72cc heads had bigger than 165 runners I'd probably buy those

[@donrutter6765]

Mutha thumpa is a botique cam designed to lope and is just a sales thing to yuppies. If you want a good cam call a good cam designer like Chet Herbert, tell them your goals, street/race compression heads etc. They will design a cam that will run circles around botique cams.

[@ghtrcp7554]

Is afr 220 ok on 383 with 142 blower? With 8.5:1 compression ratio. I dont want to go 210's. .. because ı have boost coming from blower...

[@donrutter6765]

Call AFR and ask them.

[@alexanderjones6173]

How do I get ahold of you guys at summit to get info on my build

[@SummitRacing]

Hi Alexander, you can give us a call at 1-800-230-3030!

[@uestraven]

+Summit Racing I recently bought 294cc aluminum heads for a 489 big block chevy. Are these intake runners too small or will they make up for the low end torque im losing with a single plane intake?

[@SummitRacing]

+Paul Cohen, We need some additional information from you. Can you please give our tech line a call? 1-330-630-0240. Thanks!

[@donnielovett]

I have a small block 305 with a big cam and high rise intake and i want new heads, ive heard of people use sb350 heads? And how would i go about getting vortec heads to work. And i was planning on having heads rebuilt.

[@donrutter6765]

Scoggin Dickey has the best deal on vortec heads. Best way to go. By the time you do all the machine work to fix an old set of fuelie 462 camel humps, it costs way more than a set of vortecs. Plus, you would spend a lot of time porting the fuelie heads to get equal horsepower or slightly more than stock vortecs.Iron eagles would be a better head, but also more money than vortecs.

[@SummitRacing]

There are many, many choices here at Summit Racing regarding small Chevy cylinder heads. Give us a call and we can help you chose the best set to match your combination. 1-330-630-0240

[@chrisangulo2329]

You send me a set of head 4 my 5.7 V8 92 buick roadmaster

[@marccres6619]

Well we did what you said and then we did afr,and blew all what th out said out of the water, not only did we go bigger but shaped like the new ls heads, with proper degree, a cam from the start , 9.5 to 1 carberated 470 hp 355ci your tech version we did 290hp ,well that says it all go to a good reputable builder tell them your budget and get more for your buck.

[@chev454]

I have a .030 over 350 chevy with 305 chevy heads crane energizer cam with a 284 duration with a 480 lift its mostly driven on the street whats a good cylinder head for the street.

[@turbodarealist4689]

CALVIN DENT vortec iron head is da way to go with ur combo

[@jono4316]

I have a 69 corvette 350 with 11:1 compression. What is the best head tested for the most horsepower outcome?

[@yourmom705]

Dart pro1 230cc with 2.08 intake valves

[@deerdestroyer2009]

If I have a Pontiac 400 I shouldn't put 455 heads on it then?

[@SummitRacing]

Hi deerdestroyer2009, While the 455 heads will physically bolt on and do have a slightly larger intake runner size and valve size, they also have larger combustion chambers. This is a potential problem due to it dropping your compression ratio dramatically. Grab some casting numbers and give us a call and we can help you find a piston for your 400 with those heads and get the compression ratio back. 1-330-630-0240.

[@KrOnIc343]

someone tell me why their isn't aftermarket cylinder heads for 4 cylinder engine. if so which comany makes them?

[@SummitRacing]

Dale Gribble, This would of course depend on the type of motor you plan on building. Give us a call, maybe we can help! 1-330-630-0240

[@KrOnIc343]

Summit Racing ok thank you so much! I appreciate it!

[@jackrabbit7389]

Not a huge market for 4 cylinders at least not as much as V8s

[@adamchrisman5795]

I've got a 355 with flat top pistions. With a 292 cam would 190 cc or 210cc be better? The engine is just for racing.

[@adamchrisman5795]

@Rabbi Schlomo thank you very much!

[@adamchrisman5795]

@Rabbi Schlomo I know this a awful question but how do you properly check the valve seal? Have a shop do It or am I able to?

[@donrutter6765]

Wrong cam for flat tops.

[@duramax78]

Adam Chrisman use air in the spark plug opening.

[@CensoredbyYouTube-1955]

190.

[@ak47popoff]

very cool!

[@darrellsomers5427]

What's with all this 305 stuff a 283 or a 327 is way better

[@curtthompson2787]

Instead of a 4 part series of 3 minute videos why not make 1 12 minute video?

[@SummitRacing]

Hi Curt, we appreciate your feedback. This is an older video. We have since improved our quality and format. Thanks for watching!

[@williamkirkland8582]

All ways chevy. Everybody knows that Summit is d school and needs to be put to pasture.

[@Moparmaga-1]

I'm a mopar guy & very tired of the lack of talk & part pricing. Jegs & summit are all about Chevy

[@duramax78]

Korie Creson cause they know the best.

[@mikeirish4668]

I have a 406 sbc w/9.5 -1 pistons! I would like to put a set of alum.heads W/ 2.08 intake valves .I also have Harland Sharp 1.6 roller rockers what is the best ratio camshaft for this combo ?

[@donrutter6765]

Depends on your goals. Assuming you will run street only, you will want a cam with more lobe separation angle (LSA) around 112-114 degrees. Around .525 lift, and around 270-280 duration max. The more compression you have calls for more duration. If the intake valve is open longer, you build less compression, the big pistons will restore that lost compression and gain more power. Long duration cams with low compression will rob power. If you are looking to buy heads, the Brodix site has a great chart to match the right CC intake runners to your compression/cubic inch engine.