Talk:Cam-in-block
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How about some pictures?
[edit] Removed
Remove the following (speculative and subjective without references):
- Simplicity
- By their nature OHC engines tend to be more complex than pushrod engines, particularly considering that an OHC V6 or V8 can have four camshafts. This adds cost, mass and increases the number of moving parts.
- Slight power advantages
- In any belt-driven OHC engine there is a residual loss of power through the belts that rotate the camshafts, a loss that would not happen in a pushrod engine.
Cam-in-block, or "Pushrod" engines as they are more commonly known, have become fairly obsolete, having been replaced by most mainstream automotive manufacturers.
Removed the following (speculative and subjective without references):
- Low-end torque
- Generally speaking, OHV engines are tuned to begin making power much sooner than their higher-revving OHC counterparts, to maximize the shorter overall powerband (see limitations, below). In combination with the ability to increase displacement while keeping the overall packaging compact, this can be and often is exploited for fuel efficiency, when mated to a transmission with a tall cruising gear; the extra torque keeps the engine responsive at low RPMs.
The production of torque has nothing to do with the type of valve actuation system used. IJB TA 15:11, 25 July 2006 (UTC)
Modified. See http://www.thecarconnection.com/Auto_News/Techno_Beat/In_Defense_of_Pushrods.S198.A7178.html for reference.
Again, the production of torque has nothing to do with the type of valve actuation system used. OHC engines can just as easily be made to produce large amounts of torque at low rpm, so this is not really an advantage specific to OHV engines. IJB TA 20:13, 30 July 2006 (UTC)
OHC torque: Consider Ford truck engines. IJB TA 18:48, 31 July 2006 (UTC)
Removed:
- Hydraulic valve lifters are easilly acommodated, with presurised oil readilly available from the gallery used to lubricate the crankshaft.
- For solid valve lifters, manual adjustment is easilly provided at the rocker arms where the pushrods are seated.
HLA systems were problematic in early OHC engines but this is no longer true, many OHC engines currently use HLA systems without problems. For many mechanical OHC systems the adjustment is provided on the rocker and is easily accessed simply by removing the head / valve cover. IJB TA 21:20, 4 October 2006 (UTC)
[edit] Does Not Reflect Industry Vernacular
I was surprised to find Flathead engine redirecting to Cam-in-block. I've dealt with engines for many years, and the term "Cam-in-block" has never been used.
If there are no objections, I intend to incorporate any good points of this article into the Flathead and other articles, and nominate this page for deletion. In the meantime, I will fix the redirects. --Alex 06:56, 29 July 2006 (UTC)
- What would be the reason for doing this? Searching for any of the "cam-in-block" configurations will bring up the correct article. Also breaking all of the configurations up into individual articles will likely result in stub articles. IJB TA 23:58, 29 July 2006 (UTC)
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- I see. No objections here. IJB TA 20:30, 30 July 2006 (UTC)
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I was the user who merged the articles and made pushrod, flathead engine, OHV, etc. redirects to this page. I originally posed a question at Wikipedia:WikiProject_Automobiles as to whether it would be worthwhile merging these articles, as I for one found the information contained within often repeated across these articles, and many of them were grossly inaccurate. Pushrod engine for instance discusses OHV engines, to the expressed exclusions of, say, engines with flat heads. Both are pushrod engines. And all OHC engines are, by definition, OHV engines too.
The goal was to create one, comprehensive article that discussed all engines with camshafts located within the block, thus trimming the fat out of the smaller articles and making it easier for the reader to find the information they want without having to search through five smaller articles most of which say roughly the same thing anyway.
I chose "Cam-in-block" as the title because, contrary to your assertions, it is industry jargon used to describe all engines with camshafts in the block. A quick google search will reveal that soon enough: the first couple links are wikipedia and the mirror at answers.com, but the rest are for the most part industry sites (notably GM and Chrysler sites). --93JC 17:53, 11 August 2006 (UTC)
Flathead engines are definitely not pushrod engines. The lifter.adjuster bears on the bottom of the valve stem. A pushrod goes between lifter and rocker arm in an ohv engine. There is no rocker arm (tappet) or pushrod in a sidevalve.
Cam in block is not that common a term. Never heard of "I-head". Side valves and overhead valves are quite different, while F-heads, or Inlet over exhaust engines are a combination of the two. "Valve Configurations" is what I was searching for to get here. If someone wants to merge this with pushrods, they would have to remove side valves (L heads).Seasalt 13:06, 11 October 2006 (UTC)
- Cam-in-block may be used rarely to describe these configurations but it is accurate. I-head is another rarely used term but it is also accurate. Really cam-in-block and I-head are just not the common household terms, but they are the accurate industry terms. My only concern with these articles on the cam-in-block configurations now that they have been separated is that they are titled by the common household names and not the accurate industry names, Flathead instead of L-head, Pushrod engine instead of I-head, though F-head is titled correctly. Also, I guess I do have an objection to merging cam-in-block with pushrod engine. To me it would seem best for this article to have simple descriptions of each of the cam-in-block configurations with links to the full article for each one, then to have those articles titled correctly and expanded. Then to simply have redirects on inquiries for pushrod engine to go to I-head, or flat head to go to L-head. Anyone else think this might work? IJB TA 04:07, 12 October 2006 (UTC)
Whether they are "accurate" or not, they are not exclusively "correct" either. I would leave it alone, and allow the Cam-in-Block to be merged with pushrod or Overhead Valve without flathead. Seasalt 08:06, 12 October 2006 (UTC)
- The names could stay as they are if that's what everyone here prefers. I just think that Cam-in-block should remain a separate article, there's no reason it needs to be merged. It works just fine as a description of engines that have the cam in the block. Although if it does remain a separate article I still think it should have simplified descriptions for each configuration. IJB TA 21:12, 15 October 2006 (UTC)
