[Tigers] motor mount reinforcement

[Mark Rense]

Drilling works OK for most higher HP Tigers, although I had to resort to
chaining the engine on one car as the countersunk bolts pulled through the
metal plate after a suitable amount of abuse. I’d recommend using no bigger
than a 5/16” CS bolt, a 3/8” requires too big a countersink in the thin
upper plate. A Grade 8 ¼” will also work unless you’re banging more than
350hp.

 

Two tricks: drill the countersink hole to size, but drill the backside hole
and rubber at least 1/8” larger in diameter. This is to allow the mount to
move around without constantly pulling on the bolts. Second, drill the holes
at about  10° angle from perpendicular, the mount will sag down some when
the weight of the engine is on the mount.

 

If you don’t do these two things the mount will sag enough to put the bolts
into constant tension and you wind up with a mostly solid mount causing a
lot of vibration to be transmitted to the chassis.

 

Have fun.

Bugz

 

From: Tigers [mailto:tigers-bounces at autox.team.net] On Behalf Of Brad Huff
via Tigers
Sent: Saturday, April 04, 2015 9:01 PM
To: tigers at autox.team.net
Subject: [Tigers] motor mount reinforcement

 

Just checking to see if anyone has drilled through and bolted their motor
mounts to prevent separation and the accompanying  damage to their fan
shroud and hood. If so what method did you use. 1) drilling through the
plates, countersinking the heads of the grade 8 bolts and simply a washer
and nylock nut clamped tight on the backside or 2) a similar procedure
differing only in that you would drill a slightly larger hole on the exit
side and under the clamping washer place a neoprene washer to isolate the
bolt, washer, and nut slightly from the top plate to minimize vibration
issues. Is this over thinking the problem, that is, is the vibration caused
by the through bolts even that big of an issue? Thanks to all in
advance.-Brad

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