mbruneaux Posted May 18, 2015 Report Share Posted May 18, 2015 (edited) When I bought my car I got three extra heads with it, not sure they are any good but maybe they might be worth something/keeping. One of the heads has an "M25" casting and two have an "11". Can anyone tell me what these are from? Thanks http://i984.photobucket.com/albums/ae322/mbruneaux/M25%20head_zpsfhebcdc4.jpg http://i984.photobucket.com/albums/ae322/mbruneaux/11%20head%202_zpshnrqkf5a.jpg http://i984.photobucket.com/albums/ae322/mbruneaux/11%20head%201_zpsqvfebfit.jpg Edited May 19, 2015 by mbruneaux Link to comment Share on other sites More sharing options...
87redcat Posted May 18, 2015 Report Share Posted May 18, 2015 Post up some pics if ya can. That'll help all the people in the know;) Link to comment Share on other sites More sharing options...
mbruneaux Posted May 19, 2015 Author Report Share Posted May 19, 2015 Pics added, thanks Link to comment Share on other sites More sharing options...
mbruneaux Posted September 12, 2015 Author Report Share Posted September 12, 2015 Referencing http://starquest.i-x.net/viewtopic.php?t=997&postdays=0&postorder=asc&start=0 The two heads that are marked "11" are mechanical heads but one has mechanical valvetrain and the other has hydraulic. Both seem well used so I doubt they were thrown together with out running for a while The M25 head is a hydraulic head. Link to comment Share on other sites More sharing options...
Funky Phil Posted September 12, 2015 Report Share Posted September 12, 2015 Well theyre jetvalve heads so thats not a good sign. Id look for cracks. Link to comment Share on other sites More sharing options...
ucw458 Posted September 12, 2015 Report Share Posted September 12, 2015 Yes look for cracks between the valve seats and spark plug hole. Also between the valve seats. Any cracks in those areas and the head is junk. If no cracks then those heads can be cleaned and rebuilt if necessary. Link to comment Share on other sites More sharing options...
mbruneaux Posted September 12, 2015 Author Report Share Posted September 12, 2015 How can one have hydraulic valve train if it's a mechanical head? Link to comment Share on other sites More sharing options...
Dad Posted September 12, 2015 Report Share Posted September 12, 2015 You can swap rocker shafts and arms between heads, just have to be sure Hydraulic rockers shafts are used with hydraulic lifters, the head castings them selves can be used mechanical or hydraulic. Link to comment Share on other sites More sharing options...
mbruneaux Posted September 12, 2015 Author Report Share Posted September 12, 2015 You can swap rocker shafts and arms between heads, just have to be sure Hydraulic rockers shafts are used with hydraulic lifters, the head castings them selves can be used mechanical or hydraulic. So, even if the head on the car is a "mechanical" head the hydraulic valve train will work? It does look like it was working on the other head so it makes sense. Thank you. Link to comment Share on other sites More sharing options...
Dad Posted September 12, 2015 Report Share Posted September 12, 2015 Just have to be sure it does not have the earlier long valves. Example 83 mechanical had long valves, square cut keeper grooves, then 84 had shorter valves, rounded cut grooves and valves where about .080 shorter in length, still mechanical but they lengthened the adjusting screw about .080, then about 86 they used same valves but converted to hydraulic rockers and shafts that had the extra holes to feed the lifters. Link to comment Share on other sites More sharing options...
mbruneaux Posted September 12, 2015 Author Report Share Posted September 12, 2015 (edited) Just have to be sure it does not have the earlier long valves. Example 83 mechanical had long valves, square cut keeper grooves, then 84 had shorter valves, rounded cut grooves and valves where about .080 shorter in length, still mechanical but they lengthened the adjusting screw about .080, then about 86 they used same valves but converted to hydraulic rockers and shafts that had the extra holes to feed the lifters. Were the hydraulic rocker arms different with the longer valves? Using the hydraulic cam and valve train on my head I won't have to worry about the adjuster screws, right? Maybe there is something I'm missing. I will pull the valves from the "donor" head and measure them. Edited September 12, 2015 by mbruneaux Link to comment Share on other sites More sharing options...
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