318 head porting for the average joe

[polyjohn]

A lot of work was done on 'big block' heads in the 70s with stock ports and iron intakes!

Most of the improvements were valve head angles and mostly seat angles...

This would infer that cam choice and initial flow through the port was critical.

Clearance around the valve heads in the first 100 thou of lift, is very important indeed...

 

[RustyRatRod]

Wild and crazy guy says...'' go flat ''...

View attachment 1715957510

150 cfm's, same as a 340/360 stock port!

Coolio, with a 1.500 valve...

View attachment 1715957512

I'm gonna go with a 1.550 as I have hardened seats already fitted lol...

200cfm's in, 150 cfm's out, PERFECTO...

Lordy. Has that exhaust port been flowed?

 

[ch1ll]

Is this thread dead? I’m looking for more porting knowledge and ideas.

 

[glhx]

I don’t know either. That first guy who was posting
wind n crazy was giving a lot of really good information. He got banned probably right after. probably for something minimal.
since then, I’ve not seen much on really porting these heads.
he seems like he was pretty close to giving the rest of the info

 

[polyjohn]

Most of the info necessary to port smallblock heads is covered in the first few pages!
I have done a set of 1966 273 closed chamber heads with 1.88 intakes.
This thread was perfect in helping me decide 'how far to go'...

Hogging out the ports is not needed as these heads flow excellently for daily drivers.
If you need more flow then go for a 360 head they are all practically the same...

Happy Christmas from England

 

[polyjohn]

Happy new Year to 318 head porters and other porters too lol.

I have no access to a flow bench as they are pretty rare beasties here.
I have built David Vizard home flow bench to ascertain 'valve opening' pressure drops.

I have a 1965 closed chamber head, which dropped a 1.88 valve so I've ported it out to 2.025 tulip valve.
It was cheaper than getting a new seat fitted doh...
By a strange coincidence the port chamber was greatly offset to allow easy fitting without shrouding, very like a 340 head,
Bowl blending isn't too bad either as the 318 port is rather small.

Will it be a head saver or a 'flat on its face' wrecked head???
Photo's to follow when my Android stops playing up DOH!

This is ken's 1.88 and the 2.025 goes right out to the exhaust valve like a 340 head does.
My favourite picture (lower) by WILD AND CRAZY GUY, a J head on the block, AWESOME work...

 

[Bakerlite]

I don’t know either. That first guy who was posting
wind n crazy was giving a lot of really good information. He got banned probably right after. probably for something minimal.
since then, I’ve not seen much on really porting these heads.
he seems like he was pretty close to giving the rest of the info

He's now known here as Moparoffical.

​

 

[polyjohn]

Thanx Bakerlite!

Those fingers have got me spooked lol.

Too much 'in-house' bickering on cylinder head mods these days?
Us wannabee head porters, like as much info as possible please!

Not all of 'want to' or have the inclination to buy aftermarket aluminums...
Head porting is an ART FORM and should be respected by all who partake of it...

Rusty 'J' heads are my favourite.
Grind till you make a hole and start again on another one...DOH!

 

[Dartswinger70]

When I think of all the ground up heads that will be out there now...Im just trying to get started with valve seat and guide equipment . machine shops are drying out it will be guys like me in his small garage installing valve guides for fellers from the car club a couple jobs a year...

 

[polyjohn]

Too true Swinger!

I bought all my guide reamers and k-line installers from a guy on Ebay.
I have got it down to a fine art now lol.

I only use my Mopars for a 1/4 mile at a time now!
Gas is £8 a gallon here for super 99 octane...

 

[polyjohn]

Biggest expense was the Vibro kit!!!
It pays for itself with the first 'half a dozen' heads lol...

 

[polyjohn]

Just need a valve grinder now...

 

[polyjohn]

Oh and maybe one of these, if the wife says 'YES'?

 

[volaredon]

Just need a valve grinder now...

View attachment 1716045200

I had one exactly like that one for a while... Took the motors off and over to a local electric motor shop and the "big" motor I wasn't worried about so much, can be replaced with something newer (I had something in the attic at the time that would have been perfect) but the other motor that spins the valve itself was junk. It worked intermittent for me, biggest thing it needed (I thought ( was to dismantle it and completely clean out the years of buildup, a new cord and maybe some new brushes and bearings. All stuff that can be matched up once pulled apart. But when they came back with a quote for $400 to send the armature to somewhere in Wisconsin to be rewound, I said " forget it" so mine went across the scale unfortunately.
I do know of a couple of guys who have valve grinders in their garage collecting dust, I've gone over to both of these guys places over the years and borrowed them....

 

[Bakerlite]

Thanx Bakerlite!

Those fingers have got me spooked lol.

Too much 'in-house' bickering on cylinder head mods these days?
Us wannabee head porters, like as much info as possible please!

Not all of 'want to' or have the inclination to buy aftermarket aluminums...
Head porting is an ART FORM and should be respected by all who partake of it...

Rusty 'J' heads are my favourite.
Grind till you make a hole and start again on another one...DOH!

View attachment 1716045163

View attachment 1716045164

Ah, memories. I remember cutting up heads like that with a hand hacksaw.

 

[Hysteric]

Ah, memories. I remember cutting up heads like that with a hand hacksaw.

Done that.

 

[polyjohn]

This is where I ended up lol...

I guess every head is slightly different and nothing can be taken for granted with the bowl floor waterways?

The curve up from the valve seat is exactly half a 2.02 valve head, it was meant to bee!

 

[polyjohn]

I had some head sections from Harry Weslake's place in Rye Sussex UK.

They were probably T/A heads for the 305ci Nascar program for the 1971 Wingcars?

These were my own copies from a 1971 'J' head

 

[polyjohn]

I suppose the 'W2' head was designed by Bob Mullen and Harry got the 'W1' heads for the Bigblocks?

This head cutaway has the date stamped for 1970 Weslake, nice workmanship indeed...

 

[polyjohn]

So why was the 'W1' BigBlock heads not progressed?
They had proper cooling and a heat crossover like a passenger car head.
Open chamber as per the 906 head and the extra cooling passages like the motorhome heads of 76/78 etc.
Also had the strange taper seat spark plus also like the motorhome heads!

D-shaped exhaust ports became all the rage in the 70's...
If the fuel crisis had not have happened in 73 where would we be now with heads?

This engine and a few hemi heads is all that remains of the once glorious 'Mopar branch' Weslake Engineering of the UK

 

[Cudafever]

I injoy then pic's

 

[Bakerlite]

So why was the 'W1' BigBlock heads not progressed?
They had proper cooling and a heat crossover like a passenger car head.
Open chamber as per the 906 head and the extra cooling passages like the motorhome heads of 76/78 etc.
Also had the strange taper seat spark plus also like the motorhome heads!

D-shaped exhaust ports became all the rage in the 70's...
If the fuel crisis had not have happened in 73 where would we be now with heads?

This engine and a few hemi heads is all that remains of the once glorious 'Mopar branch' Weslake Engineering of the UK

View attachment 1716047455

View attachment 1716047456

View attachment 1716047457

View attachment 1716047458

Thanks for the pics, it's the best part of this thread.

 

[polyjohn]

Glad to help and further the knowledge of Mother Mopar.

The infamous Weslake was destined for Dick Landy's collection in LA.
So I flew over in 2004 to meet 'the man' and do a deal with him.
But I couldn't go through with it as I had become so attached to our UK treasure lol.
Before I got to meet the 'great man' he fell unwell and passed to the great dragstrip in the Sky.
I tried dealing with his son Robert but he was in all sorts of problems with Dick's brother.

Fast forwards 15 years and I gets a call from Don Garlits, ''have you still got the Weslake '426 wedge' Nascar engine''?
How he found out I still had it was a complete mystery?
So I said ''it was going to be in Landy's collection, but maybe better in yours''.

Then he asked me if I had any ''Mopars to sell''?
Yes actually I do, your old Charger 500!
He was amazed it still existed and I asked him if he would like to buy both?
(Guess I would want $90,000 for the pair, $75k for the Charger 500 and $15K for the one off Nascar development engine)?

''No'' he said, ''I'm happy to have them for the museum and display them for you''...

''Let me think about that Mr Garlits''...

(My name is billy not silly) methinks...

 

[4spdragtop]

Thanks for posting the cutaways John? Have you got any more you could photograph?
Im "trying" to home port X heads and very limited info out there. Pics help.
Thanks!

This is where I ended up lol...

I guess every head is slightly different and nothing can be taken for granted with the bowl floor waterways?

The curve up from the valve seat is exactly half a 2.02 valve head, it was meant to bee!

View attachment 1716047451

I had some head sections from Harry Weslake's place in Rye Sussex UK.

They were probably T/A heads for the 305ci Nascar program for the 1971 Wingcars?

These were my own copies from a 1971 'J' head

View attachment 1716047452

 

[polyjohn]

I had some J heads that were very rusty in the waterways and they broke through even with 'mild' porting!
So I made some cutaways for myself in the style of 'WESLAKE' lol.

It was welded by a pro shop but it still went through again DOH!
The first pic shows a narrow area behind the valve stem so bee careful here...

The exhaust ports were plesently 'FAT' everywhere.