I just recently bought a set of 351w heads, and I have a few questions on them. First off the casting numbers on them are d5te-eb. I was under the impression that these heads came with 1.84/1.54 in. valves. I measure them and they appear to be 1.78/1.45 in. valves. They were made in '75. Does anyone know for certain what valve sizes these heads have. Also does anyone know whether or not the ports and combustion chambers are the same for the d5te-eb as the d0Oe heads? All my sources say they are the same (except for the d5te-eb heads have air injection) but mine seem to have the smaller valves. Another question I had is how smooth should the surface be in the area above the piston next to the combustion chambers. These areas appear to have had some rust which was removed and are a little rough. Its not too bad but its not smooth. Should I mill down the head surface slightly to smooth them over?
dave, my book says that a d5te-eb head has 1.84/1.54 valves with internal air injector ports. also 60.4 cc combustion chambers. my experience is that they are not going to be real smooth, sorta grainy.
Here is a link to a site that has the casting #'s so you can tell the valve size and the cc of the heads Link
Yes that web site is the reference which i used before I bought these heads. I noticed that all the interent sites are molded off of that one page! I measure the valves again today ( i am even using a dial calaper) and they measure 1.78in. I called ford and they could not even help me. I just recently purchased a performance part interchange manual from amazon.com. I am hoping it will give me the right information. Maybe I am measuring them wrong. I am measuring the diameter of the top valve surface. Is this right?
The 351w heads have 1.84/1.54 up to 74 after that they use the same head as the 302 1.78/1.45. The information is in , how to rebuild a small block book. It also gives the casting numbers but, it's at home.
Yes that web site is the reference which i used before I bought these heads. I noticed that all the interent sites are molded off of that one page! I measure the valves again today ( i am even using a dial calaper) and they measure 1.78in. I called ford and they could not even help me. I just recently purchased a performance part interchange manual from amazon.com. I am hoping it will give me the right information. Maybe I am measuring them wrong. I am measuring the diameter of the top valve surface. Is this right?
Well I know for sure they did not use the same heads as the 351w in 75-76. They started using the same castings in '77. My '75 351w heads have the heart shaped combustion chambers, which have less valve shroud than the 302 heads of '75. My engine is a '77 which has the large combustion chambers, small valves, and small ports. That is why I am changing them to the 351w heads. I chose the d5te-eb because they would be legal for my year ( i have to get emissions tests) and according to all the sources they had the same size ports, combustion chambers, and valves. Unfortunately I do not believe they have the same size valves.
The 75 heads are the smaller valves plus you will lose nearly 1 point in compression on a 302 73-76 years. Have them milled to get that back. Their chart is in error. Happens now and then.
LOL ya on the earlier 302s i will loose compression, but if my 351w heads are 60.4cc then I will gain about 1.2-1.5 compression points on my engine.
Not sure where your coming from but here is the info. On 73-76 302 the compession ratio is 8 to 1 with stock head volume of 58 cc. If you use a 60 cc chamber head, the ratio will drop. On 71,72 and 77 engines the ratios come out different. The reason why is the 73-76 engines have a higher block deck height that places the piston crown (deck clearence) into the bore about .022" +/-. That would suggest that at least .022 would need to be milled from the 60 cc chambers to get back over 8 to 1 compression. This is a not fully accurate amount vs compression, but illistrates the differences. Remember that the cylinder volume of a 351 is much greater than that of a 302 so the compression on a smaller cylinder will not be as high given the same chamber volume.
On some 302s the combustion chambers are 63 some are 58 some are 69cc. Mine are 69cc-70cc. The reason mine still maintain a higher compression ratio (8.4:1) than earlier 302s (8.0:1) is because mine has flat top pistons, unlike the 69-76s 302s which have dished pistons. If you look at them they look like they have a chunk taken out of them. Mine however only have the 4 valve reliefs. That is also why a good upgrade is to put '77 302 stock pistons in an earlier 302 (if they do not already have the flat tops). Like you said earlier the deck to piston distance will make a difference also.
Ok, that does make a difference in the discussion. Nothing like not knowing what's in the deck of cards! I have a 73 engine that has the block decked, using trw flat tops, plus milled and ported 73 heads for a calculated cr of 9.6. In any event good luck and remember that the volumes being delt with will control the CR regardless of what any reference says.
I looked up the deck height after being mention earlier, and here is a link of a site that might be useful. I know it has to do with the conversation .deck height clearance not too positive on the credibility of that site however
I have the exact same heads on the Turbo maverick. Chambers are 61.2 cc (after polishing), and they had 1.78/1.46 valves when I got them. The intake ports are larger than 302 ports, but the exhaust ports are the same lowly design. Thank God for die grinders! I had been using a set of '68 302 4v heads before, but changed over to these heads because I had been working on them for a while. I would guess a 40-60 HP increase (remember--this is at 10-12 psi manifold pressure.)
