MCS Length?

[GARY C]

Epoxy time... Moment of truth, I guess!

[cjperformance]

Good work, always great to see experimentation.

[GARY C]

Good work, always great to see experimentation.

We will see... I always forget how much I hate epox until I have it stuck to everything in site...

[GARY C]

Brief update on the "I Quit!" project.

No change in CFM or Air Speed with epoxy.

[steve cowan]

Gary,
did you try the intake manifold you are using-before and after?
what test pressure?

[GARY C]

Gary,
did you try the intake manifold you are using-before and after?
what test pressure?

Not sure what intake I am going to use yet, I have several.

Not sure what to look for or what I would do with it, it past test I know peak lift air flow goes down and air speed at the flange goes up and on these heads it is going to kneed epoxy...

I have not epoxied the other head yet and I am getting ready to pull an intake off an engine that I will probably use, so I can compare 3 different single planes and 1 Air Gap but since I am not going to dyno different intakes I am not sure it will tell me anything except for cfm and air speed.

[steve cowan]

Gary,
i have a set of sportsman 2 heads that are a work in progress in spare time.
i found misalignment with the roof of the head and intake (holley strip dominator as cast)
i raised the roof on the head and intake for better transition,i filled the floor of the cylinder head with epoxy and lost flow until i dropped the epoxy floor.pinch is at 2.3''
runner size 195cc,2.02 intake valve @ 86% throat.
intake i raised the roof to match head,epoxy long side at the flange and matched the short side of the runner,this is #1 cylinder long intake runner,just ran the burr over the manifold runner to de-flash.
on the bench it only lost 6cfm @ 0.650'' lift-have not checked air speed yet with intake bolted on.
like i said this a work in progress,hopefully i can get around 280 cfm with a runner size around 195-200cc.

[GARY C]

Gary,
i have a set of sportsman 2 heads that are a work in progress in spare time.
i found misalignment with the roof of the head and intake (holley strip dominator as cast)
i raised the roof on the head and intake for better transition,i filled the floor of the cylinder head with epoxy and lost flow until i dropped the epoxy floor.pinch is at 2.3''
runner size 195cc,2.02 intake valve @ 86% throat.
intake i raised the roof to match head,epoxy long side at the flange and matched the short side of the runner,this is #1 cylinder long intake runner,just ran the burr over the manifold runner to de-flash.
on the bench it only lost 6cfm @ 0.650'' lift-have not checked air speed yet with intake bolted on.
like i said this a work in progress,hopefully i can get around 280 cfm with a runner size around 195-200cc.

Yes I have done a lot of that on different head and intake combos but I don't have any dyno info before and after to know if I made it better or worse, one I did years ago had the head and intake combo within 3% of the heads alone, the heads flowed 317cfm, after some time talking with Wilson Manifolds head porter it turned out that I probably hurt shift recovery by making it to big.

I normally mock everything up on the block to be used with a .120 trim to fit gasket to raise the intake as much as possible and then raise the head port to match, once I get it mocked up on the engine I am guessing I will be raising these some so I haven't really got to carried away with the entry, I mainly wanted to see if I reduced the opening how it would effect air speed at the pinch and reducing it down to 2.05 at the opening has not hurt on the bench but who knows what it would do on a running engine?

There seems to be a complete disagreement in the industry over what % is needed for throat size and how that differs from say a low port 23* head vs a Highport 18, 15 or 12* type head, so chances are I will be grinding the epoxy out of the throat on this one head and save my self from a ton of possible unnecessary work as well as the possibility of it coming loose and trashing the engine.

[travis]

Brief update on the "I Quit!" project.

No change in CFM or Air Speed with epoxy.

So...if I am understanding this correctly, the takeaway from this is that as long as you have a decent transition from flange to PRP then that area really doesn’t matter on a flow bench with no intake attached?

My absolute novice thought at this point would be to see what the difference would be with a few different intakes attached. Then you may find that all that epoxy work is completely unnecessary.

Love the project name btw

[GARY C]

Brief update on the "I Quit!" project.

No change in CFM or Air Speed with epoxy.

So...if I am understanding this correctly, the takeaway from this is that as long as you have a decent transition from flange to PRP then that area really doesn’t matter on a flow bench with no intake attached?

My absolute novice thought at this point would be to see what the difference would be with a few different intakes attached. Then you may find that all that epoxy work is completely unnecessary.

Love the project name btw

All of the cylinder head/flowbench numbers that have been generated in the industry are for the head with a 1/2 radius (like clay) and with no intake.

Most of your intake design would be based on size and tapper, you can flow both together and I do just to see how the air speed is effected I just don't know of any info that would tell you whats good or bad with the exception of the intake being to big is a known bad.

For the most part what you will find with the intake attached is less flow and higher air speed, intake testing really needs to be done on the dyno and track.

The purpose of the epoxy and porting in general is to try to even out the size, shape and air speed without making the head to big for the CI and RPM you are shooting for, it may hurt peak rpm hp some but ideally it will help the over all tq curve, if I was starting from scratch I would use the 180cc head and port it to around 190ish so there probably would be no need for epoxy .

[MadBill]

Only a little O/T, but what epoxy did you use? (some of the better ones are NA here in the Great White North.)

[GARY C]

Only a little O/T, but what epoxy did you use? (some of the better ones are NA here in the Great White North.)

Z-Spar Splash Zone Compound, A-788, (AKA Green death) Here is where I buy... https://www.go2marine.com/product/79357 ... putty.html

I used Moroso A/B years ago on heads an intake but some let go after 21 dyno pulls, I like it better for ease of use if your just Flow Bench testing shapes and sizes but I don't trust it in an engine. Here is Professional Products (2 Big) intake with A/B.

[MadBill]

Thanks Gary. They even claim to ship to Canada!

[GARY C]

Thanks Gary. They even claim to ship to Canada!

Some of the pro guys say to coat the A-788 with this to better protect from fuels. https://www.walmart.com/ip/Devcon-2-Ton-Epoxy/20371007

[MadBill]

Are you planning to use it?