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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Push rods lifters rocker arms

Well it looks like I should replace my rockers if I'm going to replace the rest of the stuff. From what you guys have told me it's the best way to go. Does anyone have any experience with the product Moss has? They look realy nice. I just want to know if they are better than stock. And are they hard to install.
Terry B

Terry,
These are the cheep rockers.
http://www.harlandsharp.com/custom3.htm

http://cgi.ebay.com/ebaymotors/Performance-MGB-MGA-Roller-Rocker-Set-MGB-GT-Free-S-H_W0QQcmdZViewItemQQcategoryZ10076QQitemZ4596418437QQrdZ1QQsspagenameZWDVW

Moss Tuftrided shafts can be worth it also. £28 though

http://www.moss-europe.co.uk/MossUK/ProductList.aspx?SubSubCategoryID=MGB_UMGB-353

Cheers <MARK>
Mark Hester

Rocker Arm Specialties in Andersonville(?) California will rebuild rockers, and are also capable of re-ratio-ing (is that a word?) the arms. May want to give them a call....
greg fast

Terry - You might also want to talk to the people at Delta Camshaft in Tacoma, WA. Their web site is http://www.deltacam.com/ and the phone number is 800-562-5500. They refurbished the rockers on both our TD and MGB and both have been operating fine. Good luck - Dave
David DuBois

If you are replacing lifters and pushrods, you should consider MGB 18V series lifters and pushrods, they are less money and lighter. Lighter means less wear on yuor cam and a higher rpm before valve float. Happy Holidays, Bill
w.g cook

I appreciate your response but nobody has said if they have tried moss's high end rocker arm products.No they arn't cheap but when it comes to my A the best will only do.I figure if you buy the best you don't have to replace poor products later. If anyone has used moss's rockers I just want to know if they were difficult to install.
Terry B

Terry,
Not sure what you mean by moss high end rocker arm products.
Possibly quote the Moss part number, or link to it on their web site.

I use there roller rockers with 1.6 ratio in this 1860cc race engine.
http://freespace.virgin.net/marka.hester/pic107.htm

Cheers <MARK>
Mark Hester

The part I'm interested in is Moss #451-460 and #460-267,433-725. I was told the previous owner had a Fast street cam installed. #222-270. So I figured a high ratio rocker would be in order. I would be interested in opinions on this. Thanks Terry.
Terry B

Terry,
451-460 and 460-267 don't appear to be available on the Moss US or UK web site, so you may have problems ordering them.. what are these parts anyway?
http://www.mossmotors.com/
http://www.moss-europe.co.uk/

You might be interested in the spacers also AEH762/3 from here:
http://www.ukmgparts.com

There was oversize rocker shafts available at one time, but I can't find a part number for them now.

433-725 - tuftrided Rocker Shaft for longer wear, seems like a good idea, but at 3 times the price, I'd just keep replacing the standard one's.
Also the standard shafts are prone to snapping on the ends, so if you make the shaft harder. I assume it will snap easier. This is why AEH762/3 were invented.

Cheers <MARK>
Mark Hester

I stand corrected! The second part number is#460-268. The first number is for high ratio rocker kits the second is..strengthened rocker shaft outer pedestals the third was rocker shaft spacer set.This is from moss's new catalog which was sent to me not a month ago. So I would assume they are up to date.I figured if I do one part of the process why cut corners and pay for it latter? I would rather pay now drive longer. I just want to know what I'm in for as far as instalation. And if any one has done this and is there anything I should know so I don't screw up and have to do it all over again. I appreciate any help .
Terry B

Terry,
Still can't see those part numbers on their site, was it from a new MGA catalogue ? MOSS UK allows you to download the latest catalogue, but US don't.
I'm sure by the time you buy 451-460, 460-268 & 433-725 you may as well get the roller rocker set from

You might find some of the parts your looking for here also.
http://www.aptfast.com/APT_Parts/Bseries_Parts/b_Cam_ValveTrain.htm
Other useful stuff.
http://www.mgbmga.com/tech/mgb16.htm


Anyway.
It sounds like you want to do the job properly.
It's not much extra work to take the head off completely and in the process, up end it and poor some petrol or kero into the combustion chamber and check if the valves are leaking. Then you can just lap the valves a little by hand with some grinding paste if they are leaking.... Do a compression test first and you can check this. They should all be the same.

From you old thread you will know that some guys think you can change the rockers without taking the head off. It is possible, but I would say you've got a 50/50 chance of lifting the gasket and causing a leak most likely between 3 and 4 cylinders later down the track.
A head gasket is about £20 or less (or top end set), so it's not a costly exercise. You will need a torque wrench though, but you will need one of those anyway.

I've built about 20+ engine's so don't hesitate to email me if you have more questions.

Cheers <MARK>
Mark Hester

Terry, you cannot just bolt on a different ratio rocker arm without researching exactly what cam is in the engine, which valve springs are being used and whether the added lift will get you into serious and expensive trouble with coil bind.

There are lots of other places where the same amount of money as the rockers cost would stand you in better stead - have the head flowed, for instance.

If you don't want to go to all the trouble of researching and measuring, just replace whatever needs it - usually the rocker shaft and sometimes the rockers.
Bill Spohn

The Moss 222-270 cam is the Crane Cams part 342-0010. This is a very nice cam for street use. This is a fast street cam with 260/270 duration, nice idle and pretty good zip up near the red line. It is made from a new forging blank, not a regrind, and it has higher lift than a standard cam. Many regring performance cams have lift similar to a stock cam, just increased duration.

Standard cam lift is .355" at the valves. This comes from .250" cam lift x 1.42 ratio rcoker arms (stock).

This Crame cam gives .399" lift on intake and .419" lift for exhaust valves. A set of 1.60:1 ratio rocker arms will give .400" valve lift. So the Crane cam gives equal or more lift than the 1.60:1 rocker arms.

If you install both Crane cam and 1.60:1 rocker arms you get multiplied increase for valve lift, .450" for intake and .472" for exhaust valves.

Any time you do anything to increase valve lift or to reduce cylinder head height you need to check the resulting valve head clearance at full lift. In many cases (if not most) for the MG engines you may need to add clearance eyebrows in the top of the block for the exhaust valves (also for the intake valves on the 1500 engine).

Also pay attention to the cam timing specifications, which you may only find ou t about after delivery. The timing card calls for a slight change of cam timing from standard specificaton. If you're crafty you can do this with an offset woodruff key and skip the timign chain over one tooth, and no need for any special adjustable cam sprocket.

Installing a special cam or high ration rocker arms is not just a simple bolt in operation.
Barney Gaylord

Bill and Barney are right, if you swap the cam, it can take hours to setup correctly. I have a special rod that fits into the pushrod holes and I place a magnetic dial gauge on the end of it to do the cam timing. It takes hours, even with the adjustable vernier cam sprockets. Rotating the engine back and forwards many many times reading the 360 degree wheel that comes with he cam, until you achieve that manufacturers specifications.
I've Not tried the offset keys as a mate broke a key once flat changing during a 1/4 mile drag race. Game over for that engine.
With the standard valve springs, going from 1.425 to 1.6 rockers you won't get spring binding. Other springs though need to be checked.
If you maintain your standard cam but use more rocker ratio, just put at least 35" feeler gauge in, assuming you have the standard 17" already and rotate the engine by hand gently. You will find the engine goes tight if one of the valves is toughing... spark plugs removed obviously. Some people just dummy build the engine without the head gasket, but most gaskets are about 60" thick.

Engine building 101 !!!
Cheers <MARK>
Mark Hester

First off I must profess my ignorence of the British 1600 engine.Give me a 318 big block and I can walk through any rebuild.Some of the stuff you guys are talking about may as well be rocket science to me. My first MGA was some 32 years ago. A wife and 5 children facilitated it's demise for a family van. Bear in mind I'm not to old to learn. And I have the time and the cash to do it right! 55 years has taught me ,Save a dime.....Lose a dollar. I realy wish Mark Lester were my neighbor. Being an artist of well over 32 years I would definality want to institute the barter system. I't to bad the big pond is in the way.I don't realy care so much about speed any more. I just want a premo class MGA. Of course it is nice to blow the doors off of a usuper who thinks an A is just a pretty old mans car. And I must admit I am guilty of a few indescressions. I said I was old . Not dead! Any way merry x- mas to one and all and the very best in2006!!!!!!!Keep'em on the road brothers!
Terry B

"Give me a 318 big block and I can walk through any rebuild"

Uh..Terry - a 318 is a small block, not a big block, unless you are talking about non-Chrysler or .......
Bill Spohn

Boy bill what are you a scholl teacher? My remark about the 318 was just to make a point. From all I wrote you only comented on my mistake. Bill....it was just a figure of speach. Lighten up dude! You could have just wished me a happy holiday. If my text disturbes you,please don't reply. I sure didn't mean to cause you any sleepless nights. I must admit If you are a true lover of the MGA car you are like none I've met. Please by all means don't reply to any of my future inquiries about MG's. I wouln't want to offend you. Merry Christmas anyhow..Terry
Terry B

Terry, I have the Crane cam with the Harland Sharp 1.50 ratio rockers in my B. The stock dual valve springs were perfect for the task, as well as the 18V pushrods and lifters. The Moss rockers have needle bearings which can wear quickly. The Harland Sharp rockers have the stock type bushings which can be replaced, and last around 30,000 miles! Buying the Moss setup also gets you the beefy pedestals which aren't really necessary unless you have a high lift racing cam (in the .500s.)
Use solid spacers between the rockers, make sure to shim the pedestals for proper valvetrain geometry, and recurve your distributor to a 1100-3200rpm linear curve with 24 degrees of mechanical advance. You won't believe how much fun it is! By the way, lighten your flywheel while you're in there. You'll appreciate the extra effort!
Jeff Schlemmer

This thread was discussed between 11/12/2005 and 24/12/2005

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