<html><head></head><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:16px"><div id="yiv7812607182"><div id="yui_3_16_0_ym19_1_1484178824986_81470"><div style="color:#000;background-color:#fff;font-family:times new roman, new york, times, serif;font-size:16px;" id="yui_3_16_0_ym19_1_1484178824986_81469"><div id="yui_3_16_0_ym19_1_1484178824986_82010">According to British Car Specialist's Tech Talk book, you should have 7 rows front to back of 4 holes spaced 1 1/2" off the longitudinal center line and 2 1/2" apart from each other front to back and left to right. The two rear holes should only be 1/2" deep and the rest only 1" deep. This is done with a 1 3/4" hole saw with the center drill bit removed. Not sure if this will make any difference with the size hole you have in your wood frame or not. I don't know how big or how deep you made the holes. Sounds like you need new foam, drill the holes again then you need to install some webbing over the hole for some support of the foam.</div><div id="yui_3_16_0_ym19_1_1484178824986_81984" dir="ltr">Mike MacLean </div><div id="yiv7812607182yui_3_16_0_ym19_1_1484178824986_71139"><span></span></div> <div class="yiv7812607182qtdSeparateBR" id="yui_3_16_0_ym19_1_1484178824986_81468"><br clear="none"><br clear="none"></div></div></div></div><div class=".yiv7812607182yahoo_quoted"> <div style="font-family:times new roman, new york, times, serif;font-size:16px;"> <div style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div class="qtdSeparateBR"><br><br></div><div class="yiv7812607182yqt4400418731" id="yiv7812607182yqtfd39134"><div dir="ltr"><font size="2" face="Arial"> On Wednesday, January 11, 2017 4:07 PM, Austin Healeys List <austinhealeyslist@gmail.com> wrote:<br clear="none"></font></div> <blockquote style="border-left:2px solid rgb(16, 16, 255);margin-left:5px;margin-top:5px;padding-left:5px;"> <br clear="none"><br clear="none"> <div class="yiv7812607182y_msg_container">A few years back I fixed up the BN4 seat bases with repro polyurethane<br clear="none">foam inserts and after only 2000 miles they are disintegrating because<br clear="none">the 'D' hole in the reproduction wood frame is too big and offers no<br clear="none">support to the foam in the middle of the seat. As a result the foam<br clear="none">has split around the edges of the D and the centre section that is<br clear="none">unsupported is breaking free from the rest. The foam was originally so<br clear="none">firm it was uncomfortable so I did the holesaw trick to reduce its<br clear="none">stiffness but this appears to have contributed to the disintegration.<br clear="none"><br clear="none">Is this a common issue? What are others doing?<br clear="none"><br clear="none">Attached are a couple of pics, one from an unrestored BN4 showing a<br clear="none">much smaller D hole, the other is of the repro part. I'm thinking of<br clear="none">remaking the base with the smaller D hole to try and stop the<br clear="none">prolapse.<br clear="none"><br clear="none">Andy.<br clear="none"><br clear="none">_______________________________________________<br clear="none">Support Team.Net <a rel="nofollow" shape="rect" target="_blank" href="http://www.team.net/donate.html">http://www.team.net/donate.html</a><br clear="none">Suggested annual donation $12.75<br clear="none">Archive: <a rel="nofollow" shape="rect" target="_blank" href="http://www.team.net/archive">http://www.team.net/archive</a><br clear="none">Forums: <a rel="nofollow" shape="rect" target="_blank" href="http://www.team.net/forums">http://www.team.net/forums</a><br clear="none"><br clear="none"><a rel="nofollow" shape="rect" ymailto="mailto:Healeys@autox.team.net" target="_blank" href="mailto:Healeys@autox.team.net">Healeys@autox.team.net</a><br clear="none"><a rel="nofollow" shape="rect" target="_blank" href="http://autox.team.net/mailman/listinfo/healeys">http://autox.team.net/mailman/listinfo/healeys</a><br clear="none"><br clear="none">Unsubscribe/Manage: <a rel="nofollow" shape="rect" target="_blank" href="http://autox.team.net/mailman/options/healeys/rrengineer.mike@att.net">http://autox.team.net/mailman/options/healeys/rrengineer.mike@att.net</a><br clear="none"><br clear="none"><br clear="none"><br clear="none"></div> </blockquote> </div></div><div class="yiv7812607182yqt4400418731" id="yiv7812607182yqtfd81331"> </div></div><div class="yiv7812607182yqt4400418731" id="yiv7812607182yqtfd38928"> </div></div></div></body></html>