Original 427 SOHC Engine Rebuild

[Bart]

Hey guys, I have been given the task of rebuilding an original 427 SOHC for a friend of mine. The engine was running rough and upon investigation it was found to be leaking compression in between cylinders 1,2 and 3, indicating a blown head gasket. This engine has always suffered from detonation due to the less than ideal fuel we get here in Australia. The engine is now in pieces and I am about to start the process of cleaning all the parts and measuring everything up to see what is required.
It is going to be a no brainer that the compression will have to be lowered. I see on the Diamond website that they offer pistons that will drop the compression to just under 11:1, which should be O.K. with our "Premium Fuel". I will have to source a set of pistons and possibly a new set of connecting rods, from one of the vendors on this site hopefully, when the time comes.
When everything is clean and measured and we have a clear direction on which way we are going, I will no doubt have a heap of questions.
Here are some pictures of the engine and the offending head gasket:
SOHC1 by Chunga Gomez, on Flickr
SOHC2 by Chunga Gomez, on Flickr
Head Gasket by Chunga Gomez, on Flickr

[Heo]

Thats one torched gasket  Is the SOHC going in the 40
Deluxe in the background
I like the 32 roadster with a Y-Block whats the story on that

[machoneman]

Wow! Now that is one torched gasket! Jeesh, I crewed on injected/blown nitro and alky burning Hemis and never saw more than 1 or 2 torched gaskets, between cylinders....and you have 3 on one side alone! How did that engine stay running? 

[Bart]

The gasket is definitely the most damaged one that I have seen in my limited experience. The engine was running, but only just!!!!!

The 40 Coupe is pretty much stock. It has been lowered and has a mild flathead in it, which can just be seen sitting on the ground next to the SOHC. It has been converted to right hand drive as well.

The channelled 32 roadster is my Dads. It was built as a hot rod in the late 50's and was first registered as one in 1961. My Dad bought it in 1963 and it originally had a hot early flathead and running gear. He put a blown Y-block and customline gearbox and diff in it and drove it until 1977, when it was placed into the shed. He sold the blower setup and it sat until about 5 years ago when I dragged it out and got it going for him. It just has an old 292 in it, but it goes plenty fine for him.

[cjshaker]

That '32 Roadster is just plain cool!! I love vintage builds like that. I hope it never gets changed, unless you put a flathead back in it.

Good luck on the SOHC. There are a couple of builds of SOHC engines on the forum. Look them up and you'll find a tremendous wealth of information in them. But that doesn't mean you don't have to post about your build, because I'm sure everyone would love to see it come together.

[Heo]

The Roadster look much like the hotrods that where
built in Sweden in late 50s. With the fenderlaw
using 36 sparewheel covers for frontfenders

[cobracammer]

Hey Bart.  I have Diamond Racing Pistons in Mine with Eagle H beam Rods (Both pistons and Rods are forged).  Works well for me.  Dealing with Diamond was also a pleasure as I had a bit of back and forth with the ceramic coating and Teflon coating.  They were very responsive and professional.  Check them out!  http://www.diamondracing.net/

[Bart]

Bit of an update on progress. I have finally disassembled and cleaned everything. Wow, isn't there some parts to clean and sort on these things? Definitely a lot more time consuming that your regular FE, Y-Block or Windsor build.
This engine always seemed to have a lot of piston rattle noise, especially when cold. I measured the bores and got figures ranging from 4.234 to 4.238. This is with standard pistons so there is a fair bit of wear in the bores and with this excessive piston to bore clearance, no wonder it was rattling a bit!!! The crank is at 20 thou on the mains and 40 thou on the big ends. Thankfully is measured up O.K, no taper or out of round so it can go again. There is a sleeve in cylinder number one.
It turns out that the heads have been O-ringed at some stage of there lives. The head gaskets were copper/asbestos type, don't know if you should use these gaskets with O-rings or not? Anyway, the O-rings wont be going back and we will use some MLS head gaskets, Cometic etc.
SOHC3 by Chunga Gomez, on Flickr

I found some numbers and writing on the front of the block during cleaning. Do these mean anything to anybody or are they just someone's random cataloguing or similar?

 SOHC4 by Chunga Gomez, on Flickr

Another issue I has was with the rockers. The rockers are the stock Ford ones and when I disassembled the engine nine of the little elephants feet came off the end of the adjuster. Is it ok to just sit them back on the adjuster, with some lube to hold them, when reassembling the engine? Obviously the lash would have to be very excessive for them to jump out!!

Thanks again

[Barry_R]

Too bad about the bore sizes.  I have a new set of stock stroke 10.5:1 Diamond SOHC pistons at 4.236

They could have been yours for a heck of a deal.
Tried to peddle them at two FE R&R events without a sale.

[Bart]

Too bad about the bore sizes.  I have a new set of stock stroke 10.5:1 Diamond SOHC pistons at 4.236

They could have been yours for a heck of a deal.
Tried to peddle them at two FE R&R events without a sale.

Just missed out didn't we mate, pretty close

[machoneman]

Bart, no pro engine builder here but...

I had earlier commented on how the f... one could torch so many tweeners on even one bank. Now I know how that could have  happened. My words of caution here relate to the o-ringed heads. They allowed the gasses to eat away at the gasket for any number of reasons (head bolts backed off, no retorque...and more).

Point is unless you intend to mill enough off each head to eliminate the grooves, I strongly suggest you keep the o-rings and at least use a SS wire gauge that sits only a tad 'proud' of the deck surface.

Why? This would replicate a deck without o-rings and give a MLS gasket an excellent perch. Otherwise, if you leave the grooves empty I'm afraid another set of blown-between-the-cylinders gaskets are in your future. JMO but I'd seen enough f...ed up nitro engines with similar blown-gaps to hopefully know what I'm talkin' about!

   

[Bart]

Bart, no pro engine builder here but...

I had earlier commented on how the f... one could torch so many tweeners on even one bank. Now I know how that could have  happened. My words of caution here relate to the o-ringed heads. They allowed the gasses to eat away at the gasket for any number of reasons (head bolts backed off, no retorque...and more).

Point is unless you intend to mill enough off each head to eliminate the grooves, I strongly suggest you keep the o-rings and at least use a SS wire gauge that sits only a tad 'proud' of the deck surface.

Why? This would replicate a deck without o-rings and give a MLS gasket an excellent perch. Otherwise, if you leave the grooves empty I'm afraid another set of blown-between-the-cylinders gaskets are in your future. JMO but I'd seen enough f...ed up nitro engines with similar blown-gaps to hopefully know what I'm talkin' about!

Thank you very much for the input mate, once this is together and back in the car, I definitely DO NOT want to have to touch it again!!!

   

[scott foxwell]

Bart, no pro engine builder here but...

I had earlier commented on how the f... one could torch so many tweeners on even one bank. Now I know how that could have  happened. My words of caution here relate to the o-ringed heads. They allowed the gasses to eat away at the gasket for any number of reasons (head bolts backed off, no retorque...and more).

Point is unless you intend to mill enough off each head to eliminate the grooves, I strongly suggest you keep the o-rings and at least use a SS wire gauge that sits only a tad 'proud' of the deck surface.

Why? This would replicate a deck without o-rings and give a MLS gasket an excellent perch. Otherwise, if you leave the grooves empty I'm afraid another set of blown-between-the-cylinders gaskets are in your future. JMO but I'd seen enough f...ed up nitro engines with similar blown-gaps to hopefully know what I'm talkin' about!

   

Really nothing wrong with leaving the grooves as long as they don't interfere with the fire ring or any particular embossed area. They actually give the gasket something to "bite" into and help keep it form shifting around in extreme conditions, even an MLS. Lot of guys used to do this intentionally, some still do. I wouldn't recommend doing it pro-actively, but I would not surface the heads as much as it would take to get rid of the groove, that's for sure. Especially a cherry set of Cammer heads like these. An MLS gasket absolutely does not want any wire sticking out of the groove, even a few thousandths and you may not have an option as to wire stick-up height...the wire dia. is dictated by the groove width, and how high it sticks up is a function of the groove depth. If it was done right, wire should stick up about 25% of gasket thickness. Some guys will put correct wire in the groove and then surface the heads. If leaving the groove open is not an option, that's the second best thing to do and can be done with copper or stainless wire.

[Bart]

Hey guys, the time has come to purchase pistons and I have just been browsing the Diamond catalogue on-line. They advertise a piston for a 4.250" bore with a 3.784" stroke, which is what I need. They say the "nominal" compression ratio will be 10.8:1, which will suite us fine. Can anybody steer me in the right direction as to where I might be able to purchase these? I live in Australia but have a shipping address in Indianapolis, IN.

Thanks, Bart.

[preaction]

Through Jegs or summit ?