New Heart for Scarlet

[boofhead]

If anyone wanted to try out a big head small cam build for the exercise try a 5.0 HO Block standard including the camshaft and install a TFS225 High port heads with big intake and big exhaust primaries and see how it goes. Might surprise you.

[Dwayne]

If anyone wanted to try out a big head small cam build for the exercise try a 5.0 HO Block standard including the camshaft and install a TFS225 High port heads with big intake and big exhaust primaries and see how it goes. Might surprise you.

I'm selling all my bottom end bits cheap if anyone wants to give it a go.
https://www.gumtree.com.au/s-ad/stonyfell/engine-engine-parts-transmission/ford-5-0-motor-parts/1168480122

[boofhead]

While waiting for the next post here is a video to discuss

[ozbilt]

Just finished helping G with his meth addiction ...... sorry, meant meth addition .....

Sorry again, it was a unit to help him suck ......... sorry, I meant help his E car suck ........ I am not doing well here, I think I better sleep some

[Shaunp]

While waiting for the next post here is a video to discuss

My thinking is the cam was too small and the engine was too big to prove the theory entirely. With a bigger cam to allow more rpm I think the outcome would have been different, like wise if they had a smaller engine like a 302. Non the less the 165cc head surprised me, but I guess it shows an inherently good port and chamber design. In real terms if you look at the flow numbers on AFR's the 195s, the larger heads only exceed it beyond about 650 lift from memory and the 195 out flow most of the range at lower lift numbers.
I would like to see the same test with different cams on a small engine as well.

[nassi]

Just finished helping G with his meth addiction ...... sorry, meant meth addition .....

Sorry again, it was a unit to help him suck ......... sorry, I meant help his E car suck ........ I am not doing well here, I think I better sleep some

I understand that perfectly, E cars suck. Only problem is I thought Harlet sorry Scarlet was SC and therefore should blow, not suck.
Ohh, I think I see your problem.....

[boofhead]

While waiting for the next post here is a video to discuss

My thinking is the cam was too small and the engine was too big to prove the theory entirely. With a bigger cam to allow more rpm I think the outcome would have been different, like wise if they had a smaller engine like a 302. Non the less the 165cc head surprised me, but I guess it shows an inherently good port and chamber design. In real terms if you look at the flow numbers on AFR's the 195s, the larger heads only exceed it beyond about 650 lift from memory and the 195 out flow most of the range at lower lift numbers.
I would like to see the same test with different cams on a small engine as well.

Yes - the AFR165 did show how good the port design has become. it still flowed well beyond normal air speed hence the port design is quiet when it passes sonic chock. There is little more they could do to improve the port design. AFR and TFS are the only companies doing this level of development. if this was tried with an edelbrock 170 I would wager a very different result for worse The AFR195 has better low lift flow so improvement shown while the AFR220 was the right head it was chock on intake by to small ports on thr airgap as well exhaust restriction from the headers. Side note since the exhaust valve was smaller as well as header miss size and alighnment it was a problem. Also, the larger flow differences are at higher lift points then their cam was providing.

When building with a larger head the cam choice is more critical as it is less for giving.

[hybrid]

I did find it a bit weird that they sacrificed exhaust port valve size to go bigger with the intake valve.
I guess they have done their testing/research, but it just seemed a little strange to me.

[boofhead]

I did find it a bit weird that they sacrificed exhaust port valve size to go bigger with the intake valve.
I guess they have done their testing/research, but it just seemed a little strange to me.

Well they are limited to a 4 inch bore so you go down in exhaust valve size and use a longer exhaust duration in the camshaft spek to make up for it.

[Shaunp]

I did find it a bit weird that they sacrificed exhaust port valve size to go bigger with the intake valve.
I guess they have done their testing/research, but it just seemed a little strange to me.

Well they are limited to a 4 inch bore so you go down in exhaust valve size and use a longer exhaust duration in the camshaft spek to make up for it.

With the growth now of 4-1/8 and above cylinders , I wouldn't be surprised if they revise their Ex valve sizing i the future. the other option would be to Notch the top of the bores Ive done that on Holden Red motors, and MGB's as well to give valve clearance.

[hybrid]

I did find it a bit weird that they sacrificed exhaust port valve size to go bigger with the intake valve.
I guess they have done their testing/research, but it just seemed a little strange to me.

Well they are limited to a 4 inch bore so you go down in exhaust valve size and use a longer exhaust duration in the camshaft spek to make up for it.

Yeah, but many cams already go longer in the exhaust duration to make up for the supposed lack of exhaust flow in the SBF even with the regular sized valves.
But maybe the newer heads don't have the same exhaust flow issues, so it's not a consideration.

[boofhead]

I did find it a bit weird that they sacrificed exhaust port valve size to go bigger with the intake valve.
I guess they have done their testing/research, but it just seemed a little strange to me.

Well they are limited to a 4 inch bore so you go down in exhaust valve size and use a longer exhaust duration in the camshaft spek to make up for it.

Yeah, but many cams already go longer in the exhaust duration to make up for the supposed lack of exhaust flow in the SBF even with the regular sized valves.
But maybe the newer heads don't have the same exhaust flow issues, so it's not a consideration.

All depends on the head - most AFR heads have very good exhaust port flow felative to the intake at the same lift, for example close to 80% which is high while many other heads have less say around 65%. So different cams needed particularly on the exhaust side to allow the exhaust mass to be completely expelled at right point in time.

Edit'
so i decided to look at publish port flow figures for AFR165 and AFR220
at 500thou lift the AFR165 has a rlow ratio of 83%
while at 500thou the AFR220 had a flow ratio of 74%

Assuming the exhaust system is not a restriction,
The 165 head does not need extra exhaust duration. A single pattern cam is sutible.
Now in the case of the 220 it likely requires 6 to 10 deg split.

[gbx78]

While waiting for the next post here is a video to discuss

Good timing... to follow up from the end of that video and next episode on rocker arms..

Afr Stud girdle to suit heads, adjustment studs, comp cams magnum pro xd rocker arms

[boofhead]

Sexy stuff nice Christmas for you.

your rocker setup will not deflect much with the steel rockers and the stud girdle. Good choices especially given the 220lbs seat pressure and 600lbs per inch pressure.

[lukep6470]

Yes If I had to do mine now I wouldn't be using the LGM shaft rockers.

I looked them up the other day and he as doubled his price!!!