[updated:LAST EDITED ON 03-Feb-02 AT 08:47 AM (EST)]I recently purchased a complete engine that was advertised in the paper as a 302 HO froma 83 Mustang. I am just about ready to start reassembling the engine after boreing the block and buying all new internal parts. I was in the parts store the other day and this fellow I was talking to told me that Ford did not make a HO in 1983. That the engine I have is not a HO. First of all what is the difference between a HO and a regular 302. Second, How can I tell if it is a HO. The engines breather read 302 HO 4v, the valve covers are the aluminum type, double sprocket timing chain, 4 bl Motorcraft Holley. What else can I check to be sure which I have before I start assembling the engine? Also how many cubic inches will a 302 bored 30 thousand over be?
The "HO" 302 came out in the 1982 mustang. It had a double roller timing chain and a slightly higher lift cam. It still had a 2bbl carb and was rated at 157hp. In 1983 they still had the HO 302, but added an aluminum intake manifold and 4bbl holley carb. Horsepower for 83 was 175hp. You have to remember, HO 302 in those days was a big deal in a new car. The horsepower choices for the previous years was terrible, so the little effort the factory put into the 302 those years and the "High Output" designation was a big change. Looking back on it now, those engines were not much to brag about horsepower wise, although they were the beginning of what we have now. So historically you have a nice engine if you keep it dressed out like it was originally. But you could make major improvements on it with some aftermarket parts.
The firing order is differdnt on a 302 HO. On the regular 302 the firing order is 1-5-4-2-6-3-7-8. On the HO engine it is 1-3-7-2-6-5-4-8. On the HO for the models around 1990 there is 75 more horsepower in the HO engine.
I have changed the cam to a little stronger one and had some head work done. Also have added roller rockers and eliminated the smog stuff. Bored .030. Will the fireing order be different now than before?
Some of the HO's had the 351w firing order (this is the firing order previously mentioned). Some aftermarket cams have the 302 firing order, some have the 351w firing order. It is possible to have a 351w with a 302 firing order, and have a 302 with a 351w firing order depending on what you have installed. You had better check the part no. of the cam you installed so you know how to hook the sparkplug wires up (swapping the plug wires around is all you have to do).
actually 82/83 are pretty much the same...a block revisal mid year.and it'll have the 351W firing order...marine cam 260int and 273exh duration, .416lift intake, .444 exhaust.
82 had aluminum 2bbl and 83 had aluminum 4bbl.
it does NOT have flat tops from factory its only 8.4:1 compression and cast pistons..but if its been bored then that could be altogether different...its a good start though.
And don't forget Ford numbers it cylinders down the side (passenger) first, so PS side is 1,2,3,4, Ds is 5,6,7,8. Our GM friends like to number from front to back (PS side 1,3,5,7, DS 2,4,6,8). I have seen many a GM person put the plug wires wrong on their first Ford.
I don't know if you realize this, but the GM method makes sense, the Ford method does not. GM starts with the front most cylinder and calls it #1. Then looking at the crankshaft, they go 1 2 3 4 5 6 7 8 to the rear of the engine. A v8 alternates which cylinder goes to which cylinder bank, so that's why one side is odd and the other is even. I don't know how Ford came up with their numbers.
I understand the theory on why GM did it that way, but it doesn't make one more right than the other, just different. They could have numbered them from the back to the front, or from distributor to the other side.
I like the Ford way of doing it, but then I have been working on them since I was 14 years old.