littlebevan 1 Posted August 23, 2014 Just wondering if any of you guys know what all the different numbers mean on the 250 xflow heads? I have one head that has 8 written in Roman numerals cast into it next to the HF4. Can anyone shed some light? 1 littlebevan reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted August 23, 2014 It's a HF4 head...LOL But seriously check on the left hand side of the cyl head near 1-2 cyls for a code there.I'd suggest what you have is a early XE head that may be a C something head ? Thing about em is they all flow around the same but have different compression ratio's. Share this post Link to post Share on other sites
gerg 10,871 Posted August 24, 2014 A Geelong Foundry (GF) casting mark is an "F" inside a "G" which is just a modified Cleveland Foundry mark with the C changed to a G. The HF4 might be Honda Foundry, as Ford commissioned them to design them, but not sure for how long Honda made them before handing production over to Ford. Anyone shed some light on this? 1 agentkiwi reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted August 24, 2014 Honda did design and help Ford with the original castings and every single head was tweaked along the way to the final D head. The E heads are EFI and have the biggest inlet but lowest compression the C type heads have the most comp but suffer from poor chamber design and the early HF cast heads found on XD to early XE are my favorites thanks to the big open chamber but the castings are usually softer. 2 Gravelrash and agentkiwi reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted August 24, 2014 I reckon the roman numerals would be a date stamp of form. TBH I have never looked for them. I only look at the casting number and sometimes the HF number - out to the shed for a look now. I'm in the process of cleaning up a chamber of each head casting made and once I have done that I will post up a pic from unmarked thru to e2 as I now have everyone ever made plus one with a chamber that I have never seen before - which I think I posted in here once before. I'm going to make a frame for them and put them on the wall of the town shed - where I am setting up my workshop - so don't hold your breath waiting, you may well expire. 2 gerg and agentkiwi reacted to this Share this post Link to post Share on other sites
Mr Polson 10,214 Posted August 24, 2014 Yep HF means Honda Foundry. All xflow alloy heads have them that I've seen, up to 92 model. That was a HF8 head. Don't remember seeing any roman numerals though. 1 gerg reacted to this Share this post Link to post Share on other sites
littlebevan 1 Posted August 24, 2014 Ahh shit, they're tally marks not Roman numerals sorry guys. So that explains why so many HF heads split then. Share this post Link to post Share on other sites