M_R_205 5 1 Cars Posted August 21, 2009 Basicaly i have been roped into helping a mate build a redtop mini and he has heard that the engines either came with a GM head or a coscast head, whats the diference and how can i tell which is which, is there any real pint in searching for a coscast head? Cheers for any help Paul. Share this post Link to post Share on other sites
James_R 3 Posted August 21, 2009 has coscast on the it under the no.3 exhaust port. Basically better alloy used for casting, early ones can take bigger valves without changing the seats, KS ones have been known to go "porous" but generally not an issue at all. Oh also ealry ones had forged Mahle pistons in them, but really no no difference if it's fairly std. Share this post Link to post Share on other sites
DrSarty 113 1 Cars Posted August 21, 2009 early ones can take bigger valves without changing the seats How on earth? Share this post Link to post Share on other sites
welshpug 1,737 Posted August 21, 2009 by cutting them to suit I would imagine? Share this post Link to post Share on other sites
James_R 3 Posted August 21, 2009 suggest you join migweb and have a hunt for info, it's the vx eqiv to this forum only more than one type of car But yes more meat in the seat to recut etc... Share this post Link to post Share on other sites
Liquid_106 97 1 Cars Posted August 21, 2009 has coscast on the it under the no.3 exhaust port. Or an easier way to check is: As mentioned, GM ones go porus more often than not so most will have had a 'porus mod' done to them. Coscast heads are worth between £200 - £250 apparently , compared to £50-£60 for a modded GM version. Friend had a GM head running 200bhp on ITBs, never had a problem with it Share this post Link to post Share on other sites
M_R_205 5 1 Cars Posted August 22, 2009 Thanks for the info guys, we picked up a coscast head today, i was shocked that he paid £200 for it considering it was just a std bare head! Paul. Share this post Link to post Share on other sites
