Reply to "Fuel type"

quote:

Originally posted by George P:
Mike,

Issue #1:

I don't know if I've ever related this story before. Even before air pollution and catalytic converters became a predominant concern, there was a movement to remove lead from gasoline because lead was poisonous. That movement had great success in 1969. That's why 1970 was the last year for high compression engines at GM, and 1971 was the last year for high compression engines at Ford. The decision to prepare for unleaded fuel at both corporations predated the Muskie act.

I worked for the Los Angeles Department of Water and Power for 36 years. I once had to have a water sampling station installed for a pipeline that ran alongside a predominant Los Angeles freeway. That installation required an EPA soil sample, as all of my new installations required. They found lead in the soil. We had to remove soil up to a depth of four feet in order to find soil below the standard for lead contamination. There was a flippin' elementary school right next to where that sampling station was located!

Leaded gasoline was not good for folks ... this had nothing to do with air pollution ... lead was poisoning our environment, it had been poisoning us, and it was poisoning our children and grand children. Of course the oil companies opposed this, they spread propaganda insisting removal of lead would wear out engines faster. That was simply bovine excrement. One of the gasoline companies, my memory makes it difficult for me to be sure, but I think it was Sunoco, argued even back in the 1960s that lead provided no "cushion" for valve seats. I believe history has proved them to be correct.

I was around in the 1970s & 1980s when the lead was pulled from the fuel, working on other people's cars. Nobody had accelerated valve wear or seat recession problems. Everybody continued to drive their cars every day, and the cars were not wearing-out at an accelerated rate. 99% of the folks did not have the heads rebuilt & retro-fitted with hardened seats. Only the folks that took popular science magazine seriously. I shake my head sometimes when I read of people still worrying about it, after 4 decades. Cripes.

I don't remember one Cleveland engine ever having valve seating issues due to unleaded fuel ... ever. Well except for the fact that Ford put an aluminum coating on the OEM 351C valves from day one, intended to provide the seat with protection ("cushioning") the engineers thought would be eliminated when lead was removed from gasoline. But the process of applying the aluminum to the valve heads made the valves brittle, which is why the valve heads occasionally develop cracks and fall off their stems even to this day. The lesson here is not that unleaded fuel created problems ... not at all ... the failure of OEM 351C valves has been a far more catastrophic problem.

Issue #2:

The information relevant for you and I today is that valve material must be compatible with valve seats and valve guides. Stainless valves (and titanium valves too) are not as "tough" as steel valves, they must be used with iron seats or beryllium copper seats ... never hardened steel. Same goes for the valve guides, use stainless valves (and titanium too) with iron guides or bronze guides.

The big issue for owners of 351C powered cars is the OEM valves ... they must be replaced to avoid catastrophic failure issues. Most people use stainless valves for replacement. In those situations folks have had good results with the valves seating upon the iron castings, and the valve stems guided in bronze valve guides. Hopefully we can move-on beyond the topic of valves and valve seats now.

Issue #3:

I don't mean to infer I don't believe you. However, I'm hoping for a photograph! If you have a set of 4V heads with a June 1969 casting date (9Fxx) I NEED a photograph of that casting date. Please.

I have never run across or even read of "production" 4V cylinder heads cast that early. The earliest so far has been July 22 (9G22). Most castings are August 1969 (9HXX) or later. A picture of a 4V head casting with a June 1969 casting date would be a cool addition to the data Cleveland enthusiasts attempt to collect regarding the 351C.

Issue #4:

I don't intend to be argumentative, simply educational. There were no 1970 351 HO engines. Period. The 351 HO engines were solid tappet engines, they had an engine code of "R" in North American Ford & Mercury cars. The engine code "R" was assigned to a different engine in 1970, the 428 Super Cobra Jet.

In 1970 a 351 with four barrel carburetor was only available as an M code engine with 10:1 compression (advertised as 11:1), a small hydraulic cam, a small 630 cfm Autolite carburetor. It was called a 351 4V, it replaced a 351W engine with the same specification and the same power rating. It was equipped with D0AE head castings with nominally 63cc combustion chambers, and machined for a hydraulic tappet cam.

The 351C M code short block was identicle to the H code (2V) short block; it had two bolt mains (although that's truly not a durability issue), flat top cast pistons, a small light-weight crankshaft damper, a standard oil pan lacking a windage tray, and a single point distributor.