Tattersfield Head

[DBRoadster]

Hello All,

 

I recently picked up a Tattersfield Aluminum head for a Flathead 230.  Haven't CC'd the head yet, but was wondering if anyone knew off the top of their head (no pun intended  ) the combustion chamber size or the compression ratio it would produce for a '55 230 flathead with out milling any off.  It has a few very minor dings on the head surface that may cause me to mill a little off anyway.

 

Attached is picture of head.  I can get casting # of head later if that helps.

 

Thanks for the help guys!

[greg g]

I believe most of these heads provided between 8.0 and 9.0 CR depending on which motor they were mounted on. The 218 will be on the lower end of the scale (as the pistons doe not come up as high) and the 230 at the upper end. I got an Edmunds head with a bunch of pieces from a guy years ago, but it had a lot of casting imperfections and bleed coolant when the engine was running. You can check them with compressed air, by covering all the cooling passage holes with duck tape and pressurizing with low pressure compressed air and listening for leakes. I have seen it done with the compressor hooked up to the heater outlet.

[Plymouthy Adams]

I believe the piston position relative to deck surface is the same 218/230 as the only difference is the crank throw and the related rods length as the piston are also the same..thus the wrist pin position is out of the question..piston will be in the same position with either matched crank/rod set.  I believe if you look online at some of the older magazine now archived, Popular Mechanics..you will find Tattersfield ads lited and the ad may indeed mention the CR...I know Ihave seen older mags with  their ads..and the older mags also would tell you what the CR would be per amount shaved..these can be a good source for those tuning a period beefed up engine.

Edited February 10, 2014 by Plymouthy Adams

[Lumpy]

Nice looking head for sure. There is a way to figure out your compression mathematically, but I forgot how to do that. When I milled my iron head years ago I had to do all that, but my notes, as is my memory, is long gone. Can I ask what you paid for that, or what do aluminum heads cost when you can find them, generally speaking. ? When you find that formula and use it, be sure to take the true bore size into consideration. (if the engine has oversize pistons)

 

I would agree that any of the aluminum heads were high compression to begin with, so mill as little as possible. Trust me, (!!!) you won't be happy with anything over 8.0:1. If you need to lose compression, use a thick head gasket obviously, but also if you relieve the chamber above the valves, that will improve flow from the port and around the valves into the combustion chamber. Don't remove any metal from the squish area of the chamber.

 

All things considered, enlarging the combustion chamber in the head (in order to reduce compression) is more better than a thick head gasket, as the thicker the head gasket, the further the piston, at TDC, is from the squish surface, and that increases the tendency for detonation. In a perfect world, the closer the piston is to the squish surface, at TDC, without actually hitting it, is ideal. Generally speaking, .050" is the clearance between piston and head, that we try to get with flathead motorcycle engines. That allows the piston and rods to "grow" a bit when the engine is hot.

 

Okay, probably more information than you wanted, and not the information that you wanted. Too much coffee.

 

ken.

[martybose]

If you decide to use the head, make sure you check to see what length sparkplug thread you need.  I found out the hard way that my Edmunds head needed a longer length sparkplug that a cast iron stocker, and apparently that's fairly common with these alloy heads.

 

Marty

[Don Coatney]

Follow this link for some interesting reading.

 

http://books.google.com/books?id=ujMIXXdfWF0C&pg=PA25&lpg=PA25&dq=tattersfield+head&source=bl&ots=WJnkZEEfmj&sig=oFurklnQzQ-2duRBQ8RwAVb9I-s&hl=en&sa=X&ei=aQv5Up63KdO_sQT434G4DQ&ved=0CFAQ6AEwCQ#v=onepage&q=tattersfield%20head&f=false

[Plymouthy Adams]

CR is the squish of the stoke into the cylinder chamber...one needs to CC the head chamber, gasket thickness and piston below surface..the rest is mathematically the bore and stroke displacement of a single cylinder + the above CC into the head volume

 

find the CC with modeling clay and drop into a graduated cylinder and read the displacement..then convert to CI for the division step

[bob westphal]

Way back in the early sixties I bought a Edmunds head and dual intake set up for 97s. It cost me $10 because the head was warped. I took it to my school machine shop and milled it. I ended up with a 9.9 ratio. This head worked quite well as my '47 sedan was turning times in the high 15 second range with speeds in the upper 80s. Of course I used the highest ethyl on the market.

Bob

[DBRoadster]

Thanks for the quick response and all the good info!

 

Found an old Tattersfield ad, see attached.  Reads it's an 8:1 compression head.  Hopefully I don't need to mill off any or if I do I can get by with not too much if any since the compression's so high already.

 

Remind me what the stock compression ratio is for a '55 Dodge 230 Flathead?

 

Like you guys mentioned I'll look into the cooling passage leak tests and if I'll need longer plugs.

 

Thanks again guys for sharing all your great knowledge!

[Lumpy]

The Chrysler flatheads evolved from very low CR's, like 5.5 or 6.0:1 compression ratios all the way up to about 8.0:1 on the 1950's engines.

 

If you mill just the minimum off your head to clean it up, I wouldn't worry about it too much. If you get up to 8.5:1 you'll be okay by running good gas and retarding your timing a bit, or run a weak spring in your distributor (or would it be stronger?) so that your advance drops out quickly when going to half and full throttle.

 

Lots of guys will talk about compression ratios over 8.0:1, (and an engine you are going to race is another story) but I have a little bit of experience with flathead motorcycles, and went through a lot of trial and error, and mathematical equasions with my 230 engine when I first got it, and milled the head. Just my opinion, but I think one will get the most power out of the engine, and have a well behaved engine if you keep the compression around 8.0:1. Again, I'm sure you'll live fine with 8.5:1 if you pay attention to all the other details such as timing, and your advance curve. If you get too much ping, you can always easily pull the head and enlarge your combustion chambers a bit.

 

Guys do and have run much more compression than that, but after 8.0:1 you start hitting a "wall" if you will, of diminishing returns. The more you retard your timing, the more power you lose, and the higher your compression the more you'll find yourself doing that, and past a certain point you will lose more than you gain.

 

I believe I'm running around 8.5:1 or a tiny bit more. I can run on regular if I go gently on the accelerator. I do have to run Premium if I want to use a lot of throttle....and I generally do run premium, or some booster as I don't drive the car all the time, and so can afford that. If I had to do it over, I'd stick with 8.0:1 as my maximum. On the motorcycle engines, 7.5:1 works best, but they are air cooled and get much hotter than a water cooled engine. So I really believe 8.0:1 is "ideal", and a bit more you can adjust for.

 

Just some thoughts.

 

k.

Edited February 10, 2014 by Lumpy

[DBRoadster]

Cool. Thanks for the info Lumpy.  Looks like what I found, mines around 7.4:1 factory.  As you mentioned 8:1 may be a good range for reliability without getting into a radical race engine.  Looks like that's the max the factory went.

[greg g]

Tim I mentioned that because the pistons in my 218 left about 3/32nds of uncovered cylinder at TDC and the 230 was nearly dead level with the top of the block. Not scientific by any means but a definite indication of a smaller Combustion chamber all other thing being equal.

[Lumpy]

I believe there is a reason the factory never went over 8.0:1...even though one can "get away" with more, that's really the "practical" limit. I know that the flathead motorcycle engines that were seriously raced, with full factory support, engineering, and backing never went above 9.0:1. 

 

How the top of the piston sits in relation to the top of the block, or deck, is called "deck height". Greg sounds like your 218 has about 3/32nds of "negative deck height". (if the top of the piston protrudes above the deck, then that is "positive deck height") I wonder why that is, a flathead works best when the piston comes as close to the squish area of the head as possible, as mentioned before as close as possible without the pistons banging into the head when the engine is hot and revving. Does the squish area on your heads protrude down into the bore...or is that really as close to the head as the piston gets? Are all 218's like that, or are those not the right pistons in the engine?

 

ken.

[Niel Hoback]

It does give you room to shave the block in case of warpage.  Possibly Greg's has been machined.

[greg g]

my 230 engine had .010 off the deck during the rebuild, but I do not think that made a naked eye visible change. As far as I know the 218 is/was stock. Maybe a difference from 46 to 56 as the 230 is from a 56. 6.6 compared to 7.6 stock CR. yep it is a negative deck height deal.

[Lumpy]

Well...that's very interesting. I learn something new every week! Well, I do know that the higher the compression, the closer you want that piston to the head, so it makes sense that a workable CR with a negative deck height would be 6.6:1 or somewhere around there....and the older those engines are, the lower the CR, generally speaking, so it does make sense.

 

ken.

[pflaming]

"Too much coffee. . ." , absolutely impossible to have "too much coffee". Tattersfield head, please define. Did it by any chance come out of Idaho?  Nice!    

 

 

Thanks Don. Interesting. (See post #18). 

Edited February 12, 2014 by pflaming

[Don Coatney]

Follow this link for some interesting reading.

 

http://books.google.com/books?id=ujMIXXdfWF0C&pg=PA25&lpg=PA25&dq=tattersfield+head&source=bl&ots=WJnkZEEfmj&sig=oFurklnQzQ-2duRBQ8RwAVb9I-s&hl=en&sa=X&ei=aQv5Up63KdO_sQT434G4DQ&ved=0CFAQ6AEwCQ#v=onepage&q=tattersfield%20head&f=false

 

 

"Too much coffee. . ." , absolutely impossible to have "too much coffee". Tattersfield head, please define. Did it by any chance come out of Idaho?  Nice!    

 

Follow the link I posted above

[Plymouthy Adams]

^{PP...there are two T's in the name...neither of them are silent}

[greg g]

three T's.

Tattersfield was one of the companies in the 40's and 50's that made speed equipment. mostly multi carb intakes and high compression heads. Like, Thickstun, Sharp, McGurk, Meter and Ellis, they were not as well know, and Edmunds, Offenhauser, and Fenton. Ellis mostly made dual carb intakes for the light truck trade, you see a lot of international truck stuff made by them, but they also got used on Car engines. Enter the names in an e bay key word and see what pops up.

[Plymouthy Adams]

the back to back was the implied reference to the T's....lol...

[Grdpa's 50 Dodge]

I guess I really dont understand compression ratio to drive ability to performance issues.

 

I bought an unmolested car once that had a 11 to 1 cr from the factory and it was just fine to drive.

 

Another guy says you get over 9 to 1  or even 10 to 1  and it doesnt work well

 

Now we hear if we get over about 8 to 1 its diminishing returns

 

Seems I is all corn fused

[martybose]

It's all a matter of squish control and engineering.  My flathead has 9 to 1 compression, runs 91 octane and just barely pings occasionally.  My Bimmer has 11.5 compression, runs the same gas, runs smooth as glass and has twice the horsepower and torque as my flathead despite being a smaller displacement.  Of course replacing that Bimmer engine would cost more than every dime I've invested in my 47 over the years, but that's modern engineering.

 

Marty

[1941Rick]

When you talk about high compression engine of today dont forget to talk about the technology driving it.....our flatties are just down right crude compared to the new ones.

[Lumpy]

Compression in a flathead engine, and compression in an overhead valve engine are two different animals, mostly because of how far the spark plug is from the piston. In a flathead, the flame-front is considered to be kind of "weird", compared to an OHV engine. On an air cooled engine, sometimes the spark plug can be relocated slightly.

 

But if you think about it, on a OHV, the spark ignites the fuel above the piston, on a flathead it ignites it off to the side, and therein is the (or one) advantage to a OHV, and why the flame front is "funny" or less efficient in a flathead chamber, and more prone to detonation.

 

You certainly can use up to 11.0:1 in a OHV, hemispherical chamber. Been there done that.

 

However, physics is physics, and there's is a limit to how much you can squeeze the air fuel mixture, before it just wants to detonate. Remember that the air fuel mixture does not explode, it burns. When it does explode, that's detonation and ping. That's why you can ignite the air/fuel mix before the piston reaches TDC....as you know I'm sure. 

 

Then try to remember that valve timing has a huge effect on compression. You might have a 10:1 static or mechanical compression, but valve timing can lower that quite a bit, leading you to think your engine runs fine on 10.0:1 compression, whereas it's actually only squeezing the air at around 9.0:1 or something like that....just kind of making up numbers here. How much the piston is really squeezing the mixture is dynamic compression, and it's often different (usually lower) than what the static compression is, as measured by chamber volume, bore, and stroke.

 

Or in other words there are a lot of variables...when I say 8.5:1 is about tops, I'm speaking in generalizations. (and It's just my opinion) I don't doubt that someone else is getting by with more. The more overlap you have in your valve timing....that lowers your static compression. Temperature increases the tendency to detonate. Aluminum heads dissapate heat better and can run more compression generally speaking. An engine pinging or detonating with a 190 degree thremostat might not with a 160. etc. etc. !!

 

????

 

ken.

Edited February 13, 2014 by Lumpy