When I was a kid reading car mags they would never do a comparison of the large oval port heads to the aluminum versions the article was about, only the peanuts. I always felt it was so people didn't see just how good the large oval ports were and to make the new heads look better..
Yes I agree,, These are average oval port 781s.If they had big valves and really worked on, I think you'd be shocked.How closely would have came To the expensive a f r's.
I'm positive if you tuned on that edl. you could get more horsepower.It was just slap it on there and make a pull, because I had a friend.Ask me to do it.
Love your channel thanks for the awesome videos. I'm currently duplicating this exact build for a 1 ton square body. My question is what head gasket did you use with the #781 heads? I was told there are water passage differences on the newer roller block.
That is true there is water passages between the cylinders at the bottom of the cylinder block ,it's possible to drill those out on any old head gasket but if you get a performance marine gasket it will have the holes and allow coolant to pass from the cylinder block into the cylinder heads between each cylinder at the bottom as far as the part number there's a bunch of different ones that'll work
Sorry for not giving you a more direct answer but the head gasket I've been using on this motor is multi-layered steel that you would never use on the street I've been using it because I can reuse it over and over again for testing( well you might use it if you was running boost)
Very informative video my man. I subscribed. Watching in Montana. Was wanting more information on the 454. Question which 454 is in a factory SS 454 dually pickup truck?? Is it factory performance?
only 50hp? Thats alot of power ...10% of a 500 hp motor, You also have to build a base to get the higher numbers..adding a cam that take advantage of the head flow will increase that.
well, there are 496s running around with AFR 265s and make 675....for a iron oval port thats starting to get a little bit of a stretch, not that they can be made to make power..vortecpro has proven that many times over the years
What a fantastic comparison that the magazines sponsored by the cylinder head manufacturers don’t want you to see! How much do you think the pocket port was worth?
AFR,, NO Edelbrock carb,,, definitely more compression,,at least 13.5 to 1.. set the total advance of the distributor back to 26° to handle pump gas,, resulting in 600-plus HP...
you DO NOT NEED 13.5:1 to make 600 with afr 265s man , they'll do it with 10-10.5:1 and a 240 duration camshaft and run on 91 setting the timing like that on a engine with that much compression is a crutch those afr are capable of 650-675 with an 850 on a 468-475-496
Awesome video's. I have a question. Are you going to do a comparison of the 186 steel heads versus the new 186 aluminums on the 400. I watched eric's flow comparisons between the two heads. Thank you
Very nice! I will say, I'm not a fan of Edelbrock anything. I do remember seeing air flow test on AFBs that show less CFM than advertised. I'm also a fan of the Quadrajet so some think I'm mentally deficient. Oh well.
Loved this comparison. I have a spare 454 short block and 2-3 sets of large oval heads sitting in my garage right now. Also have the ZZ502/502 cam brand new in the GM box too. Those heads really respond to bigger valves but, only if you do the necessary bowl work and unshroud the chamber around the bigger intake valve. Do all that and I bet the iron heads would be within 15-20 hp of the aluminum ones. A simple cleanup of the intake runners is all that's need. People don't need to go crazy on them. Nich, how much did you shave off the iron heads to get to 113 CC's?
The motor has 1.8 scorpion rockers, Ran with a one inch spacer and a edelbrock r p m intake air gap, And yes, with those items.It did beat the 502 in hp
@@dzperformance7360 I know the Edelbrock produced heads for the 502 weren’t great, but seeing a 502 HO as delivered and with these heads swapped on would be an interesting test. I have a 502 HT motor I’m swapping to Flowtek oval port heads and a Lunati .540 lift cam to try to wake it up some. Great work on the tests.
@dzperformance7360 I'm building a 496. The short block is done, I have a bare set of those 781's, but I've been looking at those AFR 265 heads. My compression should come in around 9.75 : 1. This engine is going in a 1985 K5. Comp hyd roller cam, air gap intake. RPM's 1800-5500. Duration 273 - 279....duration at .050 is 224 - 230. lift is .538 - .538. 110 lobe separation. It's not a huge cam, but it should work well for the vehicle this engine is going in as it will be mainly street driven.
Can you help me please. I see your heads on here say 113cc I've seen other people say 781 have 113cc chambers then other people swear they are 118cc. Can you please explain this.
keeping things the same is the way to do an accuarte compairson other wise your in left field. as in your buddy head porter. just saying. thanks for sharing your priceless knowledge.
@@dzperformance7360 Everything seemed to be pretty clear, cut and dry on this test. Notice how complainers and critics never respond. lol Did the afr swap on an 11-1 454 was night and day over the GM Ovals...once th eowne started to listen about tuning/timing with modern heads. . Kick arse engine you got with a baby cam that can be driven anywhere Disappointed GM put a small hyd cam in their "ZL-1".
rewatch the video only one change, heads, same 9.3 compression for both heads this guy is a professional engine builder makes power with the least expense.
![I.N "HALLUCINATION" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/n5B5q1Hwt_U/mqdefault.jpg)
When I was a kid reading car mags they would never do a comparison of the large oval port heads to the aluminum versions the article was about, only the peanuts. I always felt it was so people didn't see just how good the large oval ports were and to make the new heads look better..
Yes I agree,, These are average oval port 781s.If they had big valves and really worked on, I think you'd be shocked.How closely would have came To the expensive a f r's.
Those are great results! Interesting the see the difference between modern AFRs and some good quality iron 781s. I really enjoy your engine builds.
Thanks for watching!
@@dzperformance7360I second what he said. Terrific videos
Thanks for the results on the Edelbrock , I have always wondered how much difference it makes compared to the Holley !
I'm positive if you tuned on that edl. you could get more horsepower.It was just slap it on there and make a pull, because I had a friend.Ask me to do it.
Thanks for vid Nick! Your a great dude! Thats alot of info. Very valuable..
I appreciate that!
Love your channel thanks for the awesome videos. I'm currently duplicating this exact build for a 1 ton square body. My question is what head gasket did you use with the #781 heads? I was told there are water passage differences on the newer roller block.
That is true there is water passages between the cylinders at the bottom of the cylinder block ,it's possible to drill those out on any old head gasket but if you get a performance marine gasket it will have the holes and allow coolant to pass from the cylinder block into the cylinder heads between each cylinder at the bottom as far as the part number there's a bunch of different ones that'll work
Sorry for not giving you a more direct answer but the head gasket I've been using on this motor is multi-layered steel that you would never use on the street I've been using it because I can reuse it over and over again for testing( well you might use it if you was running boost)
@@dzperformance7360 thanks for the quick response do you have a part # by chance for the marine gasket?
Very informative video my man. I subscribed. Watching in Montana. Was wanting more information on the 454. Question which 454 is in a factory SS 454 dually pickup truck?? Is it factory performance?
Thanks for the sub!
Not positive , But I think it would have flat top pistons ?
Good video buddy!
Thanks!
That's a lot of cheese for only 50 HP!😯 But what if you stroke it and use the expensive heads?🤷 Great stuff, thanks for sharing.😎👍
Heads would give you about 50, stroke and compression would give you an additional 50hp, There you go 620 horse out of A very mild combination
only 50hp? Thats alot of power ...10% of a 500 hp motor, You also have to build a base to get the higher numbers..adding a cam that take advantage of the head flow will increase that.
well, there are 496s running around with AFR 265s and make 675....for a iron oval port thats starting to get a little bit of a stretch, not that they can be made to make power..vortecpro has proven that many times over the years
@@cuzz63 Yeah, that's very true, a bigger cam would take advantage of those high performance c.N c ported air flow research heads
What a fantastic comparison that the magazines sponsored by the cylinder head manufacturers don’t want you to see! How much do you think the pocket port was worth?
I can only guess because i've never did a direct a = b comparison,, But I would bet 10 to 15hp
Thanks for watching and thanks for the comments..
AFR,, NO Edelbrock carb,,, definitely more compression,,at least 13.5 to 1.. set the total advance of the distributor back to 26° to handle pump gas,, resulting in 600-plus HP...
Those are cool ideas !!! I'd like to try it.
you DO NOT NEED 13.5:1 to make 600 with afr 265s man , they'll do it with 10-10.5:1 and a 240 duration camshaft and run on 91 setting the timing like that on a engine with that much compression is a crutch those afr are capable of 650-675 with an 850 on a 468-475-496
Awesome video's. I have a question. Are you going to do a comparison of the 186 steel heads versus the new 186 aluminums on the 400. I watched eric's flow comparisons between the two heads. Thank you
Tuesday night !! I'm running that motor,,, I'm Calling my shot, I think those expensive heads are only gonna be worth 15 horses
Can you post all the dyno data, BSFC fuel flow numbers with the HP and TQ in the future?
Yes,, I'm going Dyno testing on Tuesday night,, next weekend i will post whatever
@@dzperformance7360 Thank you
Very nice! I will say, I'm not a fan of Edelbrock anything. I do remember seeing air flow test on AFBs that show less CFM than advertised. I'm also a fan of the Quadrajet so some think I'm mentally deficient. Oh well.
Loved this comparison. I have a spare 454 short block and 2-3 sets of large oval heads sitting in my garage right now. Also have the ZZ502/502 cam brand new in the GM box too.
Those heads really respond to bigger valves but, only if you do the necessary bowl work and unshroud the chamber around the bigger intake valve. Do all that and I bet the iron heads would be within 15-20 hp of the aluminum ones. A simple cleanup of the intake runners is all that's need. People don't need to go crazy on them.
Nich, how much did you shave off the iron heads to get to 113 CC's?
All true,, The heads were flat milled .030 to get to 113cc.
Thanks for the input thanks for watching
@@dzperformance7360 love your channel Nick. Anything big block related and I'm all in. 😁👍
OK 👍 thanks
So a 454 with the same cam as a HO 502 made more power with worse heads?
I didn't say the heads was worse,
The motor has 1.8 scorpion rockers, Ran with a one inch spacer and a edelbrock r p m intake air gap, And yes, with those items.It did beat the 502 in hp
I'm probably not going to do it but you could put this top end of this motor on a 502 and get another, 40 hp
@@dzperformance7360 I know the Edelbrock produced heads for the 502 weren’t great, but seeing a 502 HO as delivered and with these heads swapped on would be an interesting test. I have a 502 HT motor I’m swapping to Flowtek oval port heads and a Lunati .540 lift cam to try to wake it up some. Great work on the tests.
Let me know how it works out on your 502 thanks for watching thanks for your input.
So what would those AFR 265's make on a 496?
600 to 730hp depending on cam, intake, compression
@dzperformance7360 I'm building a 496. The short block is done, I have a bare set of those 781's, but I've been looking at those AFR 265 heads. My compression should come in around 9.75 : 1. This engine is going in a 1985 K5. Comp hyd roller cam, air gap intake. RPM's 1800-5500. Duration 273 - 279....duration at .050 is 224 - 230. lift is .538 - .538. 110 lobe separation. It's not a huge cam, but it should work well for the vehicle this engine is going in as it will be mainly street driven.
Sounds like a sweet combination,, Let us know how it does
Can you help me please. I see your heads on here say 113cc I've seen other people say 781 have 113cc chambers then other people swear they are 118cc. Can you please explain this.
They were originally was 118cc
I had them surfaced milled down to 113cc
781 cylinder heads will vary on the cc of the combustion chamber.I've seen them from the factory 116 to 119cc.I've never seen a 113 that was factory..
If you mill the heads do you have to make other modifications?
Thank you for answering BTW
keeping things the same is the way to do an accuarte compairson other wise your in left field. as in your buddy head porter. just saying. thanks for sharing your priceless knowledge.
I don't understand what you're saying,, What are you trying to tell me?
😁
Your video could be great. BUT you need to do apples to apples . Please quit changing stuff ect the heads or blocks assembly. 😮
Thanks for your input.But I don't totally understand can you explain a little better?What I should been Improve on.Thanks for your feedback.
This video,, I may not Express myself well enough.The only change is the cylinder heads. with AFR.265 =571hp. with #781=515hp
@@dzperformance7360 Everything seemed to be pretty clear, cut and dry on this test.
Notice how complainers and critics never respond. lol
Did the afr swap on an 11-1 454 was night and day over the GM Ovals...once th eowne started to listen about tuning/timing with modern heads. .
Kick arse engine you got with a baby cam that can be driven anywhere
Disappointed GM put a small hyd cam in their "ZL-1".
Test results are clear as day and simple.
GM head results and afrs...what dont you understand on the video?
rewatch the video only one change, heads, same 9.3 compression for both heads this guy is a professional engine builder makes power with the least expense.