Ok so i have a motor out of a 61, and it is my understanding is that the process to convert to an unleaded engine is to change to hardened valve seats and upgrade the valves themselves. Well, the 430 i have is hard enough to find parts for, let alone find someone with specs to upgrade the valve seats. I don't know much about leaded motors, theyre a little beyond my time (born in 80;s ) Anyhow, is it reasonable to put stainless valves to it and run higher octane fuel? If so what kinda fuel would i be looking at? Pump 91-93 or like 100 octane from the airport ?I won't drive it much so that is always possible. Or, does the lead substitute stuff you can buy really work?

 

The lead substitute is costly and does not work well for high compression engines. Hardened valve seats should not be hard to find. Any good machinist should be able to fix you up. High octane fuel does not have lead in it.

 

If you are to put new valves, then you should have the seats as well. Running the old motor without lead will not cause havoc. The concern will be that the compression is high and the octane to keep it from knocking will need to be up in the 93 range.

--Mike

 

430! Now there's an interesting motor.

What I would do here, is have hardened valve seats put in, along with a full set of replacement valves, and new valve guides. It's the seats you have to worry about more than the valves themselves with unleaded, but if you're going to have it apart anyway it's a good idea just to get all new valves and eliminate any stem wear. Make sure your machinist actually looks up the spec for valve stem to guide clearance for the 430, as it can differ significantly from other motors. I found this out the hard way on an FE. Also make sure he looks up and sets the correct installed height for the valve stems.

The fuel you require depends on your compression ratio, the combustion chamber design, and camshaft timing. IIRC the 430 is one of those with the angled deck where the top part of the cylinder is the combustion chamber. I'd shoot for around 9:1 compression, maybe 10:1 if you use a big cam. If you rebuild it stock, I'd suspect you will be running the 100 octane AV gas in it.

There's a lot of ways a machinist can screw up a set of heads; make sure yours doesn't. The 430 is not that common a motor any more.

 

yeah no joke an i don't wanna buy another set of heads for it. Ok, now is there an easier way? Is there any MEL engines that were set up for unleaded? That i can pull the heads off of. When did lead go away? As for the rebuild...I am planning on keeping the motor mostly stock (it was 10.1 to 1 stock) find a tripower unit for it. Theyve been going on Ebay for $300-$400, and a rack of rebuilable holleys for $100 or so. Again, i don't need or want a hot cam, i'd actually prefer to keep it stock(for the tripower motors), but the tripower motors were up closer to 10.5 to 1. Its not gonna be a drag motor or stock car motor, just want to be able to afford to rebuild it, and drive it....

 

All engine families were converted to hardened seats during the MY 1973-74 production schedules in order to prepare for unleaded fuel introduction in 1975. Sorry I do not know of specific casting codes or part numbers related to the conversion.

 

well this family of engines' production ended in 68 IIRC so that puts me out...Unless you meant 63-64?

 

No, 73-74. Check with your machinist.

 

Some additional info:
http://www.chevron.com/products/prod...as/index.shtml

 

i would leave the seats personally. when i had my 71 460 built the builder, a very very reputable builder around here said re-seating and the risk of possibly ruining the heads wasn't worth it. he said the steal Ford used back then for seats and valves is really good and as long as i wasn't going to tow or put it in a motor home it would be just fine.
thats coming up on two years ago. I've ran it hard in two different vehicles and it's just fine.
it's a got 10.5/1 compression bored .020 balanced, mild cam.

 

my 7 litre has a 428 in it with over 90,000 miles, and has never been opened. my old 64 falcon had the valves redone at home twice, without hardened seats, and had over 600,000 miles on it before the trans went and i got rid of it, still purring like new. my old 65 falcon had 160,000 miles on it with 1 home valve redo, and never had hardened seats ,and still purred when sold. the 361 and 391 ft engines in the gas job dump trucks still have stock parts also, with over 500,000 miles each. so in my opinion, there is no reason for taking apart a good running engine just to waste money on hardened valve seats that are not needed.

 

well i wouldn't call it a good running engine, it doesn't run period which is the reason it is being gone through before i put it in thetruck and give her a shot. So you ran all those vehicles on pump gas w/ no additives then?

 

I have a 429 in my 69 T-bird. It still has the original seats in it. I had talked to Pony Carbs a while back, and they told me that all the lead additive does is gunk up the carb. I've been told by a reliable shop that changing the seats wouldn't be worth it unless I drove it hard ie: race, towing etc... They also said that the seats probably have enough lead deposit on them to last for a long time. Right now my Bird has 75,000 miles on it, and I'll put about 1,500 miles on it in a years time.

Mike B

 

We need to remember, that a lot of the later FE's, and all the FT's, had hardened exhaust valve seats from the factory (later FE's had induction hardened seats, FT's had inserts)! I've heard way too many stories of sunken exhaust valve seats in engines without hardened seats to ignore. Also, engines that were run with lead build up a coating on the valves and seats. This will allow you to run quite a while on unleaded. Problem is, one valve job and it's gone!

I say, better safe than sorry. Get hardened exhaust valve seats put in and you wont have to worry about it.