Where to buy cam, lifters, springs?

[Joe L.]

Re: Where to buy cam, lifters, springs?

I've never seen any comparison data between OE replacement and aftermarket "trick" valves, but based on my knowledge of fluid mechanics, I don't think they would make much difference on a road engine - all out racing engines are another matter.

I have also never seen any evidence that a "roller chain" is any more durable or accurate than the OE link-type chain.

I don't recommend buying OE replacement parts from GM. They sell the same Federal-Mogul and Dana Corporation manufactured parts as NAPA and other auto parts outlets, but GM prices, even with a trade discount are probably higher.

GM doesn't make any of these parts. They are all purchased from outside suppliers, but conform to the original GM drawings/specs, and these same outside suppliers market the same parts through aftermarket marketing channels under their own brand names like Sealed Power.

Of course, big block parts always seem to be a lot more expensive than SB parts, whatever the source.

Duke

Duke-----


As far as OEM versus "hot rod" parts go, it all depends on the particular part involved. Sometimes, OEM-equivalent parts are the way to go. Sometimes, OEM-equivalent parts are not the way to go. Sometimes, "hot rod" parts are not the way to go. Sometimes, "hot rod" parts add extra cost which gains one nothing for a street engine, but cause no other detriment. Sometimes, "hot rod" parts are, basically, designed for racing purposes and can be detrimental for street vehicles. It all depends on the particular part.

For example, the OEM timing sets for most 66-91 small blocks are a Morse-style chain, aluminum/nylon cam sprocket, and sintered iron crank sprocket. These work well but a MAJOR design consideration for all the pieces is noise reduction. New car BUYERS might make a purchase decision based on engine noise. There's a durability rade-off, though. That's why for most truck applications GM used a roller-type chain, cast iron cam sprocket, and steel crank sprocket.

GM's first use of a roller-type timing set for a passenger car small block or big block application was the 1996 Corvette LT4. This was a full roller chain with steel camshaft and crankshaft sprockets. It was very expensive compared to LT1 or Gen I small block set-ups. I'm quite sure that GM didn't use it because the LT1 style set-up would have worked just as well. Remember, both LT1 and LT4 are STREET engines.

For Gen 6 big blocks, a single roller style timing set is used for all. However, camshaft and crank sprockets are sintered iron (for noise control). Cloyes, which manufactures the OEM sets for GM, makes a "HD" (i.e. "hot rod") set which uses the same chain but a hardened ductile iron cam sprocket with a hardened steel crank sprocket. It's a litle noisier, but more durable. Is it NECESSARY? Of course not, but I prefer it.

All Gen III small blocks (i.e. LS-series) use a roller type chain.

[Gene M.]

Re: Where to buy cam, lifters, springs?

So I guess that some "hot rod" parts DO have a place in street bound Corvettes based on price, quality and being of equal or greater performance to the original part.

Next time don't just bag all "hot rod" pieces in a blanket statement as being of no benefit. Modern aftermarket pieces have shown to in many cases to out perform in some way (lighter, better wear, cheaper, more flow, smoother, less fuel consumed, higher rev, etc) over the old tech 40 year old design original part.

Even if a simulated computer model program doesn't show improvement does not insure there is nothing to be gained. Head flow and port matching is very subjective in model software. And lighter undercut ss valves has shown power increases in actual practice, regardless if model programs prove it out of not. I say yes for "hot rod" parts and good old American creativity..............

[Duke W.]

Re: Where to buy cam, lifters, springs?

The only aftermarket part I recommend are Crower or new Eagle SIR rods to replace OE 327 rods, especially the early ones, which are weak.

As far as aftermarket "trick" valves are concerned, do you have any documented experimental data that directly compares these valves to OE on a restoration engine configuration - either head flow or dyno tests? So far all I have ever heard is talk - they "must be better." How about some proof?

Joe - is the nylon cam sprocket even available from GM or any other source? That thing was a disaster. I recall a recent thread on SB timing chains and the early wide link chain set with steel/cast iron sprockets is still available as is the later seventies narrow set with steel/cast iron sprockets. I belivieve both are available in the Sealed Power (Federal Mogul) product line.

I recommend the wide set for SB restorations.

Duke

[Joe L.]

Re: Where to buy cam, lifters, springs?

The only aftermarket part I recommend are Crower or new Eagle SIR rods to replace OE 327 rods, especially the early ones, which are weak.

As far as aftermarket "trick" valves are concerned, do you have any documented experimental data that directly compares these valves to OE on a restoration engine configuration - either head flow or dyno tests? So far all I have ever heard is talk - they "must be better." How about some proof?

Joe - is the nylon cam sprocket even available from GM or any other source? That thing was a disaster. I recall a recent thread on SB timing chains and the early wide link chain set with steel/cast iron sprockets is still available as is the later seventies narrow set with steel/cast iron sprockets. I belivieve both are available in the Sealed Power (Federal Mogul) product line.

I recommend the wide set for SB restorations.

Duke

Duke-----



The aluminum/nylon cam sprockets for either 1966 (wide) or 67+ (narrow) small blocks have not been available from GM for MANY years. The 67+ sprocket is replaced by a hardened, ductile iron sprocket (noise reduction is not so critical for SERVICE as it is for PRODUCTION).

The aluminum/nylon sprockets are, THEORETICALLY, available from Cloyes, Sealed Power, and others. However, try to buy one from any retailer, brick-and-mortar or web-based, and you'll come up dry.

Actually, these sprockets were never manufactured by Cloyes, Sealed Power, or GM. In fact, I have it on reliable information that only one company ever made them and supplied them to all the others, the GM-supplied versions with the GM part number embossed on them but otherwise identical to all the other brands.

A while back I was bound-and-determined to get some of these. I finally had to get them from a "non-traditional supplier" that I cannot disclose. But, to get them I ended up buying 10 EACH of the small block wide, small block narrow, big block wide, and big block narrow. So, now in addition to the NOS GM aluminum/nylon sprockets I acquired over the years [none for sale], I have FORTY of these things [none for sale, either].

Actually, the aluminum/nylon sprockets would be fine for engine restorations. For the kind of mileage and use these engines will ever see, they'd be "immortal". Would I ever use one? No. But that's because I'd never use a stock-type, Morse chain set-up. For small blocks, a Cloyes 9-3100 is the way to go---tried and "true" for a LOT of years.

[Michael H.]

Re: Where to buy cam, lifters, springs?

[quote=Joe Lucia (12484);396373].

Changed my mind. I don't think I want to be involved in this discussion.

[Joe L.]

Re: Where to buy cam, lifters, springs?

You may find this hard to believe but GM engineering recommended the nylon tooth cam gear for all of the Trans-Am racing engines for the 67-69 seasons.
That's exactly what we used and we never had a problem.


Most of the trouble started about the same time new cars were shipped with 195* thermostats instead of thr 180* that had been used for years before that. As I remember, that was about 1971?
Suppposedly, the increased temp had a drastic effect on the plastic gear.

Michael-----


The first use of the 195 degree thermostat was for the 1966 model year for Corvettes equipped with K-19. Thereafter, all Corvettes equipped with AIR were also equipped with 195 degree thermostats. During the 1970-72 period, Corvettes equipped with the controlled combustion system (CCS) instead of AIR may have used the 180 degree thermostat. I'm not sure about this.

[Robert M.]

Re: Where to buy cam, lifters, springs?

Joe,

I gotta ask the question for myself and others.

You've got 40 of those things, and you're not going to sell them or wouldn't use them.
Soooo, why buy them?

I'm curious.

[Joe L.]

Re: Where to buy cam, lifters, springs?

Joe,

I gotta ask the question for myself and others.

You've got 40 of those things, and you're not going to sell them or wouldn't use them.
Soooo, why buy them?

I'm curious.

Robert-----


OCD (obsessive-compulsive disease). It's that simple.

[Robert M.]

Re: Where to buy cam, lifters, springs?

Joe,

Good enough for me.

Thanks.

[Gene M.]

Re: Where to buy cam, lifters, springs?

[QUOTE=Duke Williams (22045);396361]

[Joe C.]

Re: Where to buy cam, lifters, springs?

[quote=Gene Manno (8571);396397]

........ either head flow or dyno tests? So far all I have ever heard is talk - they "must be better." How about some proof?

Flow testing by Edelbrock is good enough for me over somebody's computer model......
STAINLESS VALVES
VALVES
THE “PRO FLO” SHAPE
A MANLEY ORIGINAL
✓Up to 40% flow increase
✓Proven performance improvement on the flow bench
Test for: Hot Rod Magazine
Tests performed by: Edelbrock
Type of cylinder head: 1969 Camaro
AVAILABLE IN THREE SERIES OF VALVES
Series “Pro Flo” Designation
Street Street Flo
Race Race Flo
Severe Duty Pro Flo
AMOUNT OF INTAKE EXHAUST
NET VALVE IMPROVEMENT
LIFT IN FLOW intake/exhaust
.150" 42% 93%
.200" 37% 27%
.250" 25% 23%
.300" 12% 22%
.350" 7% 19%
.400" 5% 14%
A 69 Camaro head is same casting as a Corvette and many other Chevy's.
yes, "hot rod" parts DO have a place in our Corvettes

Gene,

Yes, I agree that certain aftermarket parts are an improvement over the originals.............especially considering the fact that technology, computer modeling, design, and numerical control machining have advanced 40-50 years beyond what was available originally. One must always consider that there are usually trade-offs involved with any "upgrade", although there are a few that are "win-win" (improved sealants, gasketing such as one piece oil pan gaskets). Many times, reliability is a key issue. If you are not overly concerned with reliability, as some here are (considering the fact that these old cars are not "grocery getters" and generally see limited use), then some modern designs are a definite improvement over original. One such item are certain fast action, low lift camshafts which broaden and flatten the torque band with no loss of horsepower. The tradeoff here, is that most of these may require stiffer valve springs and stronger valve train components. This may lead to accelerated valve seat recession, especially on the exhaust seats, unless hardened seats have been retrofitted as well.

It is unfair and inaccurate to make blanket statements labeling all "hot-rod" parts as snake oil.

RE: your Manley Pro-Flo (reduced diameter lower stem) valve flow data. The chart shows incredible net flow improvement at low lift! Exaggerated somewhat? Also, is the whopping 93 per-cent exhaust flow improvement @ .150" lift a misprint? Typical 1.6" exhaust valve flow @ 28 inches water column is about 100 cfm from a well ported 461 head. A 93 per-cent improvement would translate to an implausible 193 cfm! Can you post a link, or reference to the article where the figures came from?

[Michael H.]

Re: Where to buy cam, lifters, springs?

[quote=Joe Ciaravino (32899);396790]

RE: your Manley Pro-Flo (reduced diameter lower stem) valve flow data. The chart shows incredible net flow improvement at low lift! Exaggerated somewhat? Also, is the whopping 93 per-cent exhaust flow improvement @ .150" lift a misprint? Typical 1.6" exhaust valve flow @ 28 inches water column is about 100 cfm from a well ported 461 head. A 93 per-cent improvement would translate to an implausible 193 cfm! Can you post a link, or reference to the article where the figures came from?

I agree. Those flow numbers are... well, sorta wishful thinking, or advertising nonsense.

I was involved in some of the testing on narrow (5/16") valve stem valves instead of 11/32" for small block years ago. Tests showed absolutely zero improvement at any RPM with the thin valve stems. Also, the valve to guide clearance had to be reduced slightly to reduce side to side movement because of the smaller stem diameter. Don't waste your money on skinny valve stems.

Two GM engineers were convinced that there would be some major improvement in air flow with the thin stem valves but, unfortunately, it just wasn't there.
GM used King Engine Service cyl heads (Detroit) for much of their "off road" cyl head mod/testing at that time and they installed 5/16" valve in everything for a while. They eventually went back to 11/32".


If the back side of the valve is reshaped to increase flow, it occurs at the expense of added valve weight. If the chamber side of the valve head is shaped to match the back side, the increase in chamber volume eats up any gain in flow. Ya can't have it both ways.

The best modification for the valve is to remove (back cut) the unused portion of the seat with a 20* undercut on the back side of the valve head, narrowing the valve seat to match that of the seat in the head.
Modification closer to the C/L of the valve head showed absolutely zero improvement.
There just isn't a lot of free horsepower in valve design once the basic shape is similar to any GM HP valve, especially in any usable "street RPM range".

[Gene M.]

Re: Where to buy cam, lifters, springs?

Joe,
Yes that was from Manley web site.
Sorry I don't have more on it from Edelbrock.
Some of the extreme differences may be errors, I just cut and paste it. But the fact remains current technology of valve train parts and head porting and design is far superior to ways of 40 years ago. And is use full in rebuilding our Corvettes.
You are correct bigger valve springs to support some after market cams may be undesirable if not matched correctly with other components. A person has to be educated in one's selection of parts.
Thank you for your interest.

[Duke W.]

Re: Where to buy cam, lifters, springs?

I was thinking more in line of a carefully controlled independent flow or dyno test of a specific "trick" valve compared to a specific OE valve on the same head, both with identical seat geometry, and I think Michael's summary of GM testing pretty much tells the story.

The backcut on the unused portion of the valve seat is very easy to do, and should be part of any precision OE engine restoration where maximum power is desired. "How to Hot Rod SB Chevies" (which has been around for 35 years) has a good, detailed drawing of multiangle seat geometry including the backcut on the inlet valve, and I've been doing/recommending this for about as long for all restoration road engines (with inexpensive OE replacement valves) where the owner is willing to go the extra distance to get maximum top end power.

Yeah, those improvement numbers are suspect as is all advertising data, and as I asked before I have to ask: Compared to WHAT? They don't say what the baseline is, but that's typical and the reason why most marketing/advertising data is suspect.

The FTC doesn't have anywhere near enough staff to keep up with all the bogus advertising out there, but people seem to be willing to believe anything.

Duke

[Clem Z.]

Re: Where to buy cam, lifters, springs?

[quote=Michael Hanson (4067);396795]

I agree. Those flow numbers are... well, sorta wishful thinking, or advertising nonsense.

I was involved in some of the testing on narrow (5/16") valve stem valves instead of 11/32" for small block years ago. Tests showed absolutely zero improvement at any RPM with the thin valve stems. Also, the valve to guide clearance had to be reduced slightly to reduce side to side movement because of the smaller stem diameter. Don't waste your money on skinny valve stems.

Two GM engineers were convinced that there would be some major improvement in air flow with the thin stem valves but, unfortunately, it just wasn't there.
GM used King Engine Service cyl heads (Detroit) for much of their "off road" cyl head mod/testing at that time and they installed 5/16" valve in everything for a while. They eventually went back to 11/32".


If the back side of the valve is reshaped to increase flow, it occurs at the expense of added valve weight. If the chamber side of the valve head is shaped to match the back side, the increase in chamber volume eats up any gain in flow. Ya can't have it both ways.

The best modification for the valve is to remove (back cut) the unused portion of the seat with a 20* undercut on the back side of the valve head, narrowing the valve seat to match that of the seat in the head.
Modification closer to the C/L of the valve head showed absolutely zero improvement.
There just isn't a lot of free horsepower in valve design once the basic shape is similar to any GM HP valve, especially in any usable "street RPM range".

what ever happen to bill king ?? he did several sets of BBC heads for me