Re: shorter pushrods???

[bgthomas@earthlink.net]

Hello Everyone

I continue to work on the TF 1500 engine for the TC which I have fitted with
a AEG122 cam and my head is 2.995" (76.07mm) thick. As I went to adjust the
valves I discovered that there is no clearance to adjust, even though I had
already fully backed out the screw to give maximum clearance when I attached
the rocker assy. Since the standard pushrod seems to go solid, my thinking
was that I would need a rod about .250" shorter. I figured this would put
me about in the middle of the adjustment range of the screw.

I know Moss sells shortened push rods for their cams, but when I called
them they could not tell me how much shorter they actually are. Also I
understand that some people have fitted spacers under the rocker support
bracket, but the impression I had was that it is better to fit shorter rods.


I also looked at Abingdon Spares catalogue. They show shims for the rocker
support and they also show a separate "TF" pushrod, which they describe as
solid. Does anybody know what difference in lenght there might be as well??
This is the first I had seen any reference to a unique pushrod for the TF.

When I mentioned this need for .250" to a fellow who is very knowledgable
about engines, although not about MG's, he could not believe I would need to
take that much off the length and was worried about the geometry of the
valve being so off that I would end up pushing the valve sideways too much,
quickly wearing out the guides.

Any and all enlightenment would be much appreciated.

Thanks again for all your help. It is really great being able to turn to
such a knowledgable group when I find myself sitting in the garage staring
at the car thinking "now what???"

Bob
TC EXU7388

[Jennifer and Hugh Pite]

Bob, the pushrods from engine # XPAG/TD2/17298 are shorter in length since
the adjusting screws are longer in length. This is from page A.32 in the MG
MIDGET TD and TF workshop manual. According to the manual, you cannot mix
the parts.
Hugh Pite TC, J2

----- Original Message -----
From:
To:
Sent: Wednesday, January 26, 2000 6:45 PM
Subject: [mg-tabc] shorter pushrods???


> Hello Everyone
>
> I continue to work on the TF 1500 engine for the TC which I have fitted
with
> a AEG122 cam and my head is 2.995" (76.07mm) thick. As I went to adjust
the
> valves I discovered that there is no clearance to adjust, even though I
had
> already fully backed out the screw to give maximum clearance when I
attached
> the rocker assy. Since the standard pushrod seems to go solid, my
thinking
> was that I would need a rod about .250" shorter. I figured this would put
> me about in the middle of the adjustment range of the screw.
>
> I know Moss sells shortened push rods for their cams, but when I called
> them they could not tell me how much shorter they actually are. Also I
> understand that some people have fitted spacers under the rocker support
> bracket, but the impression I had was that it is better to fit shorter
rods.
>
>
> I also looked at Abingdon Spares catalogue. They show shims for the
rocker
> support and they also show a separate "TF" pushrod, which they describe as
> solid. Does anybody know what difference in lenght there might be as
well??
> This is the first I had seen any reference to a unique pushrod for the
TF.
>
> When I mentioned this need for .250" to a fellow who is very knowledgable
> about engines, although not about MG's, he could not believe I would need
to
> take that much off the length and was worried about the geometry of the
> valve being so off that I would end up pushing the valve sideways too
much,
> quickly wearing out the guides.
>
> Any and all enlightenment would be much appreciated.
>
> Thanks again for all your help. It is really great being able to turn to
> such a knowledgable group when I find myself sitting in the garage staring
> at the car thinking "now what???"
>
> Bob
> TC EXU7388
>
> ------------------------------------------------------------------------
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>
>

[Bob and Carolyn Grunau]

Hi Bob, shorter pushrods are available from Crane Cams in Florida. I had to
use these pushrods on my race XPEG engined TC as the large cam lobes
required them. Crane should be able to give you the exact length.
Alternatively you can draw the end off your pushrods and shorten the tube.
Then re-install the end. Tig weld the ends to the tubes as required.
Easiest if you select pushrods that already have one end loose in the tube,
a not uncommon occurrence.
I am surprised that you need shorter pushrods with only 0.027" milled off
the head. Has anybody milled anything off the rocker pedestals? This could
cause your problem. Or possibly the cam has large lobes??
I have the Crane short pushrod part number somewhere but can't put my hands
on it right now. If desperate I can possibly find it.
regards, Bob Grunau

----------

> From: bgthomas@earthlink.net
> To: mg-tabc@egroups.com
> Subject: [mg-tabc] shorter pushrods???
> Date: Wednesday, January 26, 2000 9:45 PM
>
> Hello Everyone
>
> I continue to work on the TF 1500 engine for the TC which I have fitted

with

> a AEG122 cam and my head is 2.995" (76.07mm) thick. As I went to adjust

the

> valves I discovered that there is no clearance to adjust, even though I

had

> already fully backed out the screw to give maximum clearance when I

attached

> the rocker assy. Since the standard pushrod seems to go solid, my

thinking

> was that I would need a rod about .250" shorter. I figured this would

put

> me about in the middle of the adjustment range of the screw.
>
> I know Moss sells shortened push rods for their cams, but when I called
> them they could not tell me how much shorter they actually are. Also I
> understand that some people have fitted spacers under the rocker support
> bracket, but the impression I had was that it is better to fit shorter

rods.

>
>
> I also looked at Abingdon Spares catalogue. They show shims for the

rocker

> support and they also show a separate "TF" pushrod, which they describe

as

> solid. Does anybody know what difference in lenght there might be as

well??

> This is the first I had seen any reference to a unique pushrod for the

TF.

>
> When I mentioned this need for .250" to a fellow who is very knowledgable
> about engines, although not about MG's, he could not believe I would need

to

> take that much off the length and was worried about the geometry of the
> valve being so off that I would end up pushing the valve sideways too

much,

> quickly wearing out the guides.
>
> Any and all enlightenment would be much appreciated.
>
> Thanks again for all your help. It is really great being able to turn to
> such a knowledgable group when I find myself sitting in the garage

staring

> at the car thinking "now what???"
>
> Bob
> TC EXU7388
>
> ------------------------------------------------------------------------
> GET A NEXTCARD VISA, in 30 seconds! Get rates as low as 2.9%
> Intro or 9.9% Fixed APR and no hidden fees. Apply NOW!
> http://click.egroups.com/1/915/0/_/60353/_/948941159/
>
> -- Check out your group's private Chat room
> -- http://www.egroups.com/ChatPage?listName=mg-tabc&m=1
>
>

[Skip Kelsey]

Bob:

The stock cyl. head is 76.75mm thick. 8.6 to 1 is 76.25mm thick,and 9.3 to
1 is 75.50mm thick. so yours is still within specs for the road. The TF
pushrod is very slightly shorter than the TC unit, plus the adjusters are
longer. This was due to the change from the TC cam with a .308 lift to the
TF cam with a .315 lift. I have put TF cams in TC/TD engines before and
didnt have the trouble that you are having. Are you using the TF grind, I
dont remember?
I have been using custom made pushrods made by Smith Bros. up in Bend,
Oregon.

Cheers:

Skip Kelsey.........................

At 06:45 PM 1/26/00 -0800, bgthomas@earthlink.net wrote:

>Hello Everyone
>
>I continue to work on the TF 1500 engine for the TC which I have fitted with
>a AEG122 cam and my head is 2.995" (76.07mm) thick. As I went to adjust the
>valves I discovered that there is no clearance to adjust, even though I had
>already fully backed out the screw to give maximum clearance when I attached
>the rocker assy. Since the standard pushrod seems to go solid, my thinking
>was that I would need a rod about .250" shorter. I figured this would put
>me about in the middle of the adjustment range of the screw.
>
> I know Moss sells shortened push rods for their cams, but when I called
>them they could not tell me how much shorter they actually are. Also I
>understand that some people have fitted spacers under the rocker support
>bracket, but the impression I had was that it is better to fit shorter rods.
>
>
>I also looked at Abingdon Spares catalogue. They show shims for the rocker
>support and they also show a separate "TF" pushrod, which they describe as
>solid. Does anybody know what difference in lenght there might be as well??
> This is the first I had seen any reference to a unique pushrod for the TF.
>
>When I mentioned this need for .250" to a fellow who is very knowledgable
>about engines, although not about MG's, he could not believe I would need to
>take that much off the length and was worried about the geometry of the
>valve being so off that I would end up pushing the valve sideways too much,
>quickly wearing out the guides.
>
>Any and all enlightenment would be much appreciated.
>
>Thanks again for all your help. It is really great being able to turn to
>such a knowledgable group when I find myself sitting in the garage staring
>at the car thinking "now what???"
>
>Bob
> TC EXU7388
>
>------------------------------------------------------------------------
>GET A NEXTCARD VISA, in 30 seconds! Get rates as low as 2.9%
>Intro or 9.9% Fixed APR and no hidden fees. Apply NOW!
>http://click.egroups.com/1/915/0/_/60353/_/948941159/
>
>-- Check out your group's private Chat room
>-- http://www.egroups.com/ChatPage?listName=mg-tabc&m=1
>
>
>
>