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MG TD TF 1500 - RE Laystall head

Will the person with the Laystall for sale please contact me salsburyrocketman at yahoo dot com. Sent you an email but haven't heard back. Let me know if the other person bought it and if not... Give me a phone # and I'll contact you directly

Thanks
W. A. Chasser Jr

You do know that the LL head is wider, and so stock carbs will not fit under the bonnet? And that you will have to run premium fuel?

(That being said, I have two of them, one original and one new...)

Tom Lange
MGT Repair
t lange

Tom,
1) The head is different, in that it extends out past the pushrods, but does it really extend the ports out farther? Can't be but a fraction of an inch? Not having one handy to compare with, it is difficult to visualize.

2) If that's the case, would you expect a blower interfere with bonnet, too? That would probably require custom support bracket and longer belt.

3) Compression ratio? Makes supercharging with Laystall even more of a challenge.


JRN JIM

I was not aware of this. Guess I will be Fabricating a blister for a side panel down the road. Re extending out past the pushrods>>> does this mean machining is involved to gain clearance for the pushrods or is there a fitment issue with the push rod side cover?. What is the compression ratio of the head with stock mowog pistons? I guess, if I wanted to supercharge this down the road I will have to get a set of 8:1 forged blower pistons built? Fuel not an issue
W. A. Chasser Jr

The stock head has one large cavity underneath where the pushrods drop through, but I notice the Laystall has the machined surface the full width, but shouldn't be any wider, just gives an appearance of extra width there.
The 1 1/2" carbs and stock manifold hit the bonnet even on a stock head.

Ports extedend farther out on the Laystall?
JRN JIM

Not the only head for the XPnG in town. Here's a X-flow made in The Netherlands ...

Gord Clark
Rockburn, Qué.

Gordon A Clark

Gord - how much?

Tom Lange
t lange

Tom,

Absolutely no idea, but I'm sure its greater than $10.

Gord Clark
Rockburn, Qué.
Gordon A Clark

Looks like you could adapt a set of webers to that Nice looking piece of billet. Who makes that?

For those who have shown interest in a Laystall contact Butch or Tom. I ended up and bought a NOS Laystall today From Lawrie Alexander. Dated Feb 1972. It was fully machined and shelved by its PO ( a friend of his) as a spare. Very trick porting, combustion chamber, cc'd and polished, trick valves and springs and retainers, mild milling to give a 8:1 compression. The manifold side had been shaved presumably to allow for the questionable hood clearance. It is and 1/8" wider the center of the head stud hole to the flange. It a beautiful looking piece and I almost hate to use it. Should go well with Len's 236/236 grind, and valvetrain/ roller lifters I will be springing for.
W. A. Chasser Jr

Gord that looks like air injection ports....are you sure we are looking a an Xpag head and not a B series?
MG LaVerne

No, LaVerne. I took this picture at Stoneleigh a couple of years ago. Definitely for an XPnG. It was on display at one of the many booths.

Unfortunately, I forgot to ask about source and availability.

For those interested, B&G are still selling the LL head and the last time I looked, they were advertising it on their web-site. But I believe it is still a 'special order' item.

Gord Clark
Rockburn, Qué.
Gordon A Clark

The Laystall head has all the same fitting dimensions as the original head except for the manifold gasket face which is about 10 millimetres (.4 inches) further out. I think the Laystall Compression Ratio was originally about 9:1 on a 1250cc engine. If the engine capacity has been increased, this will increase the Compression Ratio. A 9.0:1 head on a 1466 engine will have a 10.3:1 CR.

The Laystall combustion chamber is a different shape ... broader but shallower and the port behind the valve throat is more streamlined than the original but these factors do not affect fitting. The exhaust valves have 45 degree seats instead of the original 30 degrees.

I have been running a Laystall head (dated early 1950s) on my supercharged race TC for 42 years. I have never seen a modern repro' so I can not say if they vary from old ones.

oTCagonally, Bob Schapel
R L Schapel

Hi Bob,
Interested to know what CR you have on your SC TC. We have a X-flow head (same as on the picture from Gord in this thread)
We have a CR of 8.1:1 on our 1350cc XPAG, with a front placed Volumex SC. And Gord, the price was £2000, made in England. Just a couple of them was made and unfortunately I believe that most of them gave their owners trouble.We have been struggling with ours for some time now and after making special rollerrockers to handle problems with valve and pushrod distance, making the pushrodholes larger, welding the waterholes, and reducing the diameter, drilling new waterholes where the holes in the gasket were placed, and then welding and milling the area around the oilchannel three times to handle porosities and cracks.......!
We now hope that the X-flow head will be tight and are now concidering if we should decrease the CR with a thicker specialmade headgasket.
We are very much loking forward of testing the car on the road so we hope that the problems are behind us! :-)
Anders & Ingvar / Sweden

T Dahlberg

Hi Anders and Ingvar,
The current (1366cc) engine has been in the car for 19 years! I have had the head off twice although it is overdue to be re lapped to the block. I have only told my brother the CR and boost! The engine is only intended for racing although it should be OK on the road as long as it could use its usual Avgas 100 fuel. The previous (1250cc) engine was also in for 19 years but had more work done on it over that time. I didn't keep any secrets then. It should have had a CR of 9:1 but it would have been higher as the pistons protruded above the deck. The combustion chambers were 35cc each, gasket 4.5cc and head thickness about 75mm. I ran 8 psi boost from the Godfrey Marshall J 100 blower. If I revved it too high it would lift the head and lose water!

The current engine is "dry decked". All gasket holes are sealed and the water flows out the back of the block and into the back of the head. It still lifts the head (as black leakage marks show on the solid alloy "gasket" and black spatter on the water pump,) but it does no harm. I would like to use higher torque on the head nuts but I fear it might distort the poor old alloy head!

oTCagonally, Bob
R L Schapel

Wow I didn't expect this post to get so much attention. I learn something new every day. I'd post pics of my NOS head but I don't know how to resize pics on my new computer with windows 8. Miss my old XP
W. A. Chasser Jr

Just found that "Where the Rubber Meets the Road, Part 3", by Dave Barnett, refers to the new Laystall heads available from Brown and Gammons. He says the chamber capacity of the new heads is 40 cc, giving a CR of 8:1 on a 1250 engine and 9:1 on a 1466 engine. I guess Brown and Gammons themselves could give information on their heads.
oTCagonally, Bob
R L Schapel

£1695 from B&G, plus vat and £ to $ conversion. Shipping. PJ

Oh yeah, we pay no vat!
Paul S Jennings

Thanks RL for the info. I'm going to check the deck height and CC my chambers to double check. Mine has been decked. Lawrie measured it and I rhink I was wrong on the CR estimate. Think he said it was about 9.6:1 It clearly had been machined as there is some flashing in the stud and cooling holes that need to be dressed up. If anyone can tell me how to reduce the resolution on my pics in windows 8.1 I'll be happy to post pictures of my head
W. A. Chasser Jr

plan to send my short block in and have everything double checked and clean before reassembly in the next few days once my budget recoups from my moss motors order and head purchase. Been in touch with Len re his 236/236 cam and rocker setups. Hoping this will perk up the old girl when she is once back on the road.
W. A. Chasser Jr

Hi Bob,
You say that you would like to use higher torque on the headnuts.
How much?
/Anders
T Dahlberg

Somewhere on this site (a few weeks ago) I saw an image of a Laystal head article from a Dec 1952 Autosport Magazine. Later I googled Laystal and found a similar magazine on EBay!! (Should have bought a lottery ticket immediately!) I will include images, hoping they are clearer than those published before. My copy is slightly different in that it has "book reviews" instead of an advert for Laystal Chromhard liners. I hope it is of some interest .... the performance data, CR and material are mentioned. Will send images later. Can not seem to get both attached to this!

Anders, I would like to use 55ft lbs or more. (I have stronger head studs.) I was told to use 36ft lbs by an expert MG mechanic in about 1970. It is 8 years since I had the head off ... and I should have written down what I used! I think it was probably about 45 ft lbs. I emailed Brown & Gammons asking what was now recommended but have had no reply.

oTCagonally, Bob Schapel

R L Schapel

I look forward to it Bob
W. A. Chasser Jr

Hopefully this is page 1 of 2. Yay, I managed to re size the file .... trouble is I will forget how to do it tomorrow!!

Bob Schapel

R L Schapel

This is page 2 of 2.

Bob Schapel

R L Schapel

This was the title page of the older version I found. The next page (page 1) was headed "Reprinted from AUTOSPORT issue dated December 26, 1952" (The Magazine I got on EBay).

Some details and pictures of small piles of Laystalls can be found at www.xpagengineering.co.uk ...Maybe they are Brown and Gammons' source?

Bob Schapel

R L Schapel

Yes Bob, XPAG engineering does produce & sell the Laystall head.
I always use hardened flat washers under the cylinder head nuts.
Len
Len Fanelli

The TF that I bought in July has a Laystall head, and apparently solid lifters and an uprated cam. Ive been trying to gain tuneup clearances etc for this engine. XPAG Engineering gave me valve clearance spex and Tappet clearance spex.....what else do I need?
Frank Bice

Frank Bice - please contact me off-line.

Tom Lange
MGT Repair
t lange

This thread was discussed between 30/07/2014 and 15/09/2014

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