View single post by Esprit2
 Posted: 05-01-2005 06:02 pm
PM Quote Reply Full Topic
Esprit2

 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 572
Status: 
Offline
For both front and rear seals,  insert them into the housings from the outside inward.   The open gap in the seal (between rim and seal lip) faces into the engine.

Tricks to make it easier:

The seal bores end in a sharp corner/ edge.   Use a sharp Xacto knife or utility knife to cut a slight chamfer/ lead that will help the seal get started.

Heat the housing to around 210° F.   The kitchen oven works,  but you may have to send your wife off to the mall or something first.   I've used the gas barbecue grill on low.   In either case,  don't trust the temp controls...   use a separate oven thermometer.

Remove from the oven and smear the bore with a sealant.   Smear the seal's OD as well.

Press the seal in while the housing is still  hot.   Move too slow and let it cool down and there's no point in going through the exercise.

These steps make it easier,  but not easy.   Sort of the difference between impossible and aggrevatingly difficult.   Especially the rear seal which is complicated by the need to be pressed in to a dimension (2.5mm / 0.100" from the inner face).   I've made a disc  0.100" thick that's a loose drop-in fit in the housing bore.   Lay the housing on a flat surface,   drop in the disk followed by the seal.   Drive the seal in until it bottoms on the disc.

The real solution is a hydraulic press.   Everybody needs one of those.

Where do you get your seals?   I've had trouble with the non-Lotus front seal from JAE.   They're gray and have a ribbed OD instead of smooth.   I destroyed three in a row before buying a Lotus-branded part...  which went in with minimal complaint.   From the markings on the face,  the Lotus part has a 67.71mm OD while the JAE part has a 68mm OD.

I'm not a big fan of using silicone to seal the housings to the block.   You'll get better results with Loctite 518 or 515,  Permatex Anaerobic Gasket Maker 518 (private label of Loctite 518),  Permabond A-136,  Loctite 504 (old technology),  Wellseal  or Permatex Aviation Form-a-Gasket 80017 (17 = package size,  4 oz bottle).   Don't use Permatex Form-a-Gasket No. 1  or  No. 2 in the little white tubes.

Use the gaskets.   If you insist upon not using a gasket,  the seal with 518 or A-136.

The stock screws for the rear seal housing are Allen drive button heads (at least on a Lotus engine).   I've had some trouble stripping the drive,  so I switched to hex-heads.   They work fine with the stock iron flywheel,  but interfered with an aftermarket aluminum flywheel.   Just a word to the wise.   If you switch to hex heads,  double check for adequate flywheel clearance.

Tim Engel