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"Spotty" cam

16K views 19 replies 6 participants last post by  extinctmake 
#1 ·
I saw this advertised on ebay. At first I thought it was a reproduction 068 cam, then I read the description again after reading the specs.

Has anybody ever heard of Spotts Performance?

Here is the ebay ad:

The famous "068" high lift cam by Spotts Performance

My most popular cam for the person who "wants a little more cam"

This cam is like using the Ram Air 068 cam with 1.65 rocker arms, but for less money!* This cam has the same lift while using 1.5 rockers - so you can use all the factory rockers, springs etc.

Good idle with slight lope, makes good vacuum for power brakes. Works great for stock 389-455 (or stroker engines) but makes more power.
Most popular for 389-400 engines - but great for 455s
I have this cam in a heavy 74 Firebird with 455 and 6X heads and car runs 12's in quarter mile with no head porting!

I also have this cam in many 389 tripower engines - just ask around

Good for cars with AC and power brakes and stock rear gears. Makes excellent low end torque.

Works on high and low compression
9:1 or higher for 326/350/389/400 engines
8.5:1 or higher for 421/428/455 and 461 plus stroker engines)

Great for AC and power brake cars.
This cam makes power, while still using stock valve springs
or use my or VSH1 springs
(clearances must be checked by competent machine shop) .

cam specs:

288/298 adv duration
214/224 duration at .050
443/465 lift with 1.5 rocker arms
449/471 lift with 1.52 rocker arms
473/496 lift with my 1.6 roller rockers (see my other auctions)
112 lobe separation, 69 degree overlap
Intake Center line: 108 Degrees
Valve Adjustment: Zero Lash Plus ½ Turn

Works great for Q-jets or tripower - an perfect for any carburetor and intake combination - even dual quad. Cam requires poly locks for rocker studs.

Buy from a Pontiac engine builder! Bid in confidence - I've been building Pontiac's and supplying parts since 1979

Made by same company that supplies Melling, Crower, Summit and others - US made! Many of those company's do not supply US made lifters!!!
Note the lifters - these are the best - beware of lifters that do not look like these.
I have NOS lifters that are exactly the same as what I am offering,and these are the only ones I use in my engine builds.
Want to hear this cam? search on you tube for my Pontiac engine builds under spotperf* - this cam is in dual quad 428 video
Free shipping - in stock and* I ship quick!*
Bonus offer! free cam lube and new cam key included!


I have been thinking of using just the tried and true 068 cam for my 389 build.....if the machine shop gives it a good bill of health after its been cleaned and magnafluxed.
 
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#4 ·
Looks like a good cam and should be about what you are looking for. Your heads should have the stock rocker arm studs which means you will torque the rocker arm nuts. The cam states, "Valve Adjustment: Zero Lash Plus ½ Turn " which means you will need to go with something like these (just an example) Crower 86051-16: Sure Lock Rocker Nuts 3/8" Stud Diameter | JEGS

You can also convert your press-in studs with later style screw-in studs, but this will require more machining $$$. I think with the 1.5 rocker ratio (stock) and the 443/465" lift you should be OK with the stock rocker studs. However, if you do elect to buy this cam from Spotts, simply call/email them with the heads you will be using and get their recommendation on the studs and the locking nuts. I would also get their matching lifters and valve springs so as to have a complete and matched/compatible "kit".
 
#5 ·
Do you think the lifters he sells are true Pontiac lifters instead of the Chevy-type lifters some cam outfits sell with Pontiac cams?

I am leaning towards using the 068 cam for my build. It is a proven design and my goal is to restore my engine while making the necessary changes to burn low octane swill.

I was also looking at the Melling SPC-7 068 clone. But do you think I could get away with the higher lift (443/465 lift with 1.5 rocker arms vs. .407/.407 lift for the classic 068) with the Spotts 068 with 1.65 rocker-like grind?

I agree that getting the cam with a matched set of valve springs and other valve train pieces is the way to go. I plan on using the pressed in rocker arm studs. A bunch of the wise men on this site have told me I really don't need the screw-in studs for what I'm trying to put together.

I'll have to visit Spotts' web site and find out more about them.
 
#6 · (Edited)
"... I plan on using the pressed in rocker arm studs..."


To me, that settles your cam choice. I wouldn't use anything bigger than an 068 clone, like the Melling SPC-7, with 1.50 rockers--1.52 roller tips max. This way you can get by with less spring pressure, which will be less likely to pull a stud.

Many might say they have used much bigger cams & higher spring pressures, with press-in studs, and have never pulled a single stud. Many others have not been so lucky. So, it's your call. How lucky are you ?

"...Do you think the lifters he sells are true Pontiac lifters instead of the Chevy-type lifters some cam outfits sell with Pontiac cams?..."

Paul is the real deal. Don't think he would knowingly sell poor quality parts. Many Pontiac guys now recommend the Hylift Johnson "R" lifters. Paul Knippen sells these.

https://www.facebook.com/PaulKnippensMuscleMotors/

Another lifter that may be a good choice, is the Crower Cam Saver. They splash extra oil on the cam lobes. Sounds like a good idea. Don't know who makes those lifters. Haven't read any bad reviews, so far.

http://www.jegs.com/i/Crower/258/66056X3-16/10002/-1
 
#7 ·
I have another question about the 068 cam. I have seen differing specs for the 068 cam. I have an old GTO source book that contains factory brochure info and advertisements with specs.

The 1965-66 389 Tri Power, 1967-68 400 H.O., 1969-70 400 Ram Air III, and the 1971-72 455 H.O. is listed using the 068 cam. The duration and overlap is the same for all of these: 288 degrees intake/302 degrees exhaust and 63 degrees overlap. What I find different is the lift. It isn't much, but for the 389 Tri Power the lift is listed as .409 intake & exhaust. The 400 H.O. and the Ram Air III is listed with .414 intake/.413 exhaust, and the 455 H.O. is .410 intake/.413 exhaust. The Melling clone is listed .409 intake/.408 exhaust. The duration for the Melling (part number SPC-7) is 212 degrees intake/225 degrees exhaust @ .050.

It isn't much difference, but it appears some of these 068 cams have different specs. Could rocker arm ratio differ, causing the difference?

I have one foot in the door towards using the 068 cam. Will it still be effective with a 9:1 compression ratio? I know the 1960s Pontiac engines that used this cam had ratios above 10:1. The 455 H.O. was 8.4:1, but my engine is a 389, so maybe the smaller displacement could be a factor.

I have heard about those cam saver lifters. The machinist mentioned using a different oil with ZDDP. He mentioned Brad Penn oil. The 068 doesn't have a really high lift, so maybe there is less stress on the lobes. It couldn't hurt to use the oil with the higher zinc content nonetheless.
 
#8 ·
Cam specs are not universal. One cam grinder cam use a different point on the cam lobe to get his/her advertised specs. Some measure advertised duration at tappet lift (hydraulic or solid) while other measure at valve lift, ie .006" lift at the tappet is .009" at the valve. Nothing you listed is enough to make any difference.

Factory SAE specs for the 4-speed HO "068" cam is Intake Lift @ zero lash - .414" +/- .011
Exhaust Lift @ zero lash - ..413" +/- .011" Int.Opens BTC @31, Int.Closes ABC @77, Int.Duration 288, Ex Opens BBC @ 90, Ex Closes ATC @ 32, Ex Duration 302, Overlap 63.

The outer valve springs are the same for both the intake/exhaust 63.3-69.3 lbs @ 1.5613" measured height - valves closed, 132.7-142.7 lbs @ 1.1473" measure height - valves open.

Inner springs show a slight difference for the open measured height for intake/exhaust 54.7-59.7 lbs @ 1.5213" measured height - valves closed, 118.6-128.6 lbs @ 1.073" measure height -intake valve open and 1.083" - exhaust valve open. (.010" difference noted, but unknown as to why. Possibly the seat cut in the head for the exhaust valve or the difference between the 30 degree seat of the intake valve and 45 degree seat of the exhaust valve.)

In Jim Hand's Pontiac book, he states that the Lobe Separation Angle (LSA) is 116 with the Intake Centerline (IC) being 113. LSA is the distance in cam degrees between the intake lobe center and exhaust lobe center. IC is the peak lift point of the intake lobe as measured in crankshaft degrees. The intake and exhaust may not always have the same peak lift point due to unsymmetrical lobe designs of the cam.

:thumbsup:
 
#9 · (Edited)
I appreciate your input Jim. That is some keeper information. All that said, I guess I should just focus on the specs of the actual "068-type" cam I select and not worry about the specs from GM back in the 1960s and 70s.

The cam I have my eye on his the Melling variant of the 068. This is part number SPC-7. I have noticed many Pontiacs are running around the streets with a Summit "Classic Cam," part number 2801.

Then there is that Spotts cam I started this thread with that is a 068 ground like a 068 using 1.65 rocker arms while still using the 1.5 rockers.

I still have to hear back from the machine shop regarding the condition of my engine, but he emphasized using a roller cam and I think that is excessive for what I'm looking to achieve with this engine. I want to present some flat tappet alternatives if we agree that he will build this engine for me.

Many thanks for the straight scoop on these Pontiac cams.
 
#10 ·
Your machinist may highly recommend the roller, but it is your engine and if costs are important, then he should respect that and not give you any crap over it. If he is willing to sell you a roller set-up at the same cost of a flat tappet cam/lifters, then tell him he can do it. If not, then there is no reason why he cannot build an engine with a flat tappet cam. If he is uncomfortable meeting your needs, then go elsewhere after you get all the parts checked out - simple enough.

My impression of this guy, based on your input, is that I would not allow him to build my engine until you have hammered out what will be going into the engine (parts), his labor costs, assembly, and a final tabulation of what the engine is going to cost you - to which you will hold him to it. Don't let him pull the "there may be some hidden items that I may run into while assembling" on you. That leaves him open to charging you more. Crank grinding, cylinder boring/honing, head rebuilding, assembly, etc. should all be set pricing so you know exactly what it will cost you for machining and all your parts will be known as to their costs and you can supply them to him rather than him order the parts - if you chose to go this route.
 
#11 ·
Absolutely Jim. I am willing to procure the parts. I know some places want to use their own parts, but I'm sure there is some mark up. I guess I will have to talk it over with him once I find out if my engine is a good core.

I have some items already on hand. I have a set of screw-in rocker arm studs, poly lock rocker arm nuts, cam bearings....little things. There are some parts I'd like to use such as a Melling 60psi oil pump and I am interested in the BOP one-piece rear main seal.

As for the roller cam, I don't know why he'd push for a roller cam and tell me he hasn't used a flat tappet cam in years. I am going to aim for a quality stock rebuild with dished pistons, his advice to use Eagle rods, and do something with the valves by either going with Ferrea stainless valves and/or hardened valve seats. The more I think about it, the more I am going to pick the Melling 068 cam. I will use the recommended Melling lifters, push rods, and valve springs with it. I think with my 3.23 gear, 4 speed, and stock AFB and recurved points distributor, this engine will run well using the tried and true 068 cam.

I guess we'll see when I hear back from the machine shop.

Here's some photos of what I'm trying to restore.
 

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#14 ·
From what I can see in your pictures, your parts don't look too bad, but that could change once you have them hot tanked and magnafluxed. But I think you should be OK.

If going with the "068" cam, you should not have a problem with the rocker studs pulling out. But if you plan to keep your studs and want a little insurance, you can have the rocker pedestals drilled and pin the rocker studs with a roll pin. This was done on early factory Hi-Po engines before screw-in studs were the norm. Aftermarket cam companies used to sell a kit to do just that when using some of their hi lift cams. Pinning them would eliminate additional machine work in milling your factory pedestals flat/square and drilling/tapping the pedestals so that the screw-in studs will seat correctly. Your machinist should be able to do this with little trouble and cost.

Make sure you also get a new aftermarket hardened intermediate oil pump shaft to replace the original when using the Mellings 60 PSI pump. If you have a little extra play money, Butler has a blueprinted 60 PSI Mellings pump for $159.95, part # BPI-M54DS-PRO. I purchased one for my 455 build and it looks great. Have not built my engine yet, but it will be going on it. Just feel safer using it, not that there is anything wrong with the standard Mellings pump as I have used these as well with no issues. Butler Performance - Pontiac Oil Pumps Oil Pans Dipstick Tubes
 
#15 ·
I already have a set of screw in studs. I didn't know there was more than tapping the holes for the studs. I will have to ask about pinning the existing studs.
I want to use a Melling oil pump. Not sure about the Butler one you mention. I'm building a mostly stock engine with a few minor upgrades.
 
#16 ·
It's been about three weeks since I dropped my engine off to the machine shop. I know he is busy and he knows I'm no hurry. Maybe it takes a while to tank it etc.

In the meantime, I have been reading more about not just cam choices (Melling and Summit and Spotts), but pistons as well.

Three weeks ago I figured I'd use Ross dished pistons for my 389. The machinist mentioned a brand of piston I have never heard of. Anybody ever hear about or use Diamond pistons? The machinist said the Ross pistons are not as user friendly on a street engine and more noisy. Being that the pistons will be most expensive part of the engine, I should find out more about Diamond pistons and whether it is true that the Ross pistons are not what they once were. I always thought Ross has a great reputation.

The longer the wait to hear the fate of my 389, the more time I have to ruminate and kick ideas about what to do with the engine.

As always, I appreciate and value you guys' input.
 
#17 · (Edited)
I can't speak about Diamond pistons as I have never used them. Reading reviews online, they seem to be ok.

The problem I see is that their catalog shows nothing for the 389, but has the 400/455 pistons -but am sure they can custom make a set. In order to run the 400 pistons, which would be the simplest for your machinists to do, is you will need to bore your engine .060" over which could put it near its limits. Why bore the block .060" over if .030" or even .040" (using custom sized pistons) will work and it leaves you with another overbore in the future if need be. Not saying it can't be bored past .060" if the cylinder bores are sonic checked for wall thickness to support a larger overbore should you need it. You can also sleeve cylinders, but this becomes costly.

The next problem is that the pistons need to be for the 389 heads with the 17 degree valve angle and not the 1967 and up 14 degree valve angle. Now you may not have any issues with piston to valve clearances with the 068 cam or if you have deeper valve pockets in the piston tops. This must be measured/clearanced if you use the 400CI pistons with their stock valve relief locations with a 389CI head.

Then you have issues with compression. Most of the 400CI pistons are flat tops and you compression with the stock 389CI heads may be as factory - up around 10 to 1 compression which could mean racing gas. You want a dished piston top to lower compression so you can use the more friendly pump gas.

To address all three problems, 389CI .030" over piston, correct valve angle reliefs in the top of the piston, & dished to lower compression, you may be looking at a custom forged piston to which Ross, and I am sure others, can make. Costs will be typically more so you want to inquire as to pricing.

The old TRW, now Federal Mogul, pistons were a popular forged piston and suspect they still do the job at reasonable costs. These pistons are said to be heavy, but from what I have read it was due to a heavy wrist pin to make the piston/pin weight the same as the factory Pontiac cast piston/pin for a direct replacement. You can go lighter with a lighter piston pin. You will need to balance your engine anyway as you will be using forged rods, so a lighter pin should be a consideration. If the valve reliefs are near 6.6 cc's, you will have about a 9.6 compression with a 72 cc head. http://butlerperformance.com/i-2445...et-1959-1966-389cid.html?ref=category:1234820

If you gotta go .060" over, the Keith Black Icon forged pistons have the valve reliefs for both early and late heads which gives you 11 cc's for valve relief area which with a 72 cc head should put you in the 9.5 compression range. Further down is the "D" shaped piston top with 14 cc's which would put you at a better 9.2 compression as long as the valves have enough clearance and won't strike the piston. http://butlerperformance.com/c-1234...ternal-pistons-icon-forged-pistons-by-kb.html

You will also have to take into consideration the length of the rod you will be using, stock forged I-beam - 6.625", or aftermarket I or H-beam at 6.7" or 6.8" lengths. These numbers will have to be matched to your piston choice as the piston pin height has to be made to work with rod length.

HOWEVER, the best bang for your buck, and to have all your parts matched, and to get the compression ratio you need........may be the Butler 389 stroker rotating assembly if their is no additional hike in price if you need custom pistons. Let your machine shop talk with Butler and possibly build your engine with these parts. 2 strokers to choose from @ $1,898.00 (plus shipping). You can up your cubic inches for more torque and power while appearing stock on the outside and still go with the 068 cam. http://butlerperformance.com/c-1234...es-stroker-kits-389-blocks-421-480-cu-in.html

Price out the individual parts, forged pistons/pins, rings, forged rods, crank rod/main bearings, balancing, and grinding/polishing your 389 crank versus the complete Butler kit and see what the difference is in getting a good comparison on price/value.

That said,...........more to consider. :thumbsup:
 
#18 · (Edited)
You know what Jim? When the machinist recommended the Diamond pistons he mentioned boring the engine .060 to 400 cid.

I don't want to bore the block that far. Geeteeohguy already made a good point a long time ago to me that boring the 389 to 400 uses up the block and makes a hot running engine.

I know Ross can custom make the right style piston for a 389 vs. the 400 versions. I did check the Butler stroker kit that would turn my 389 into a 421 with a .030 bore. It is tempting considering the pistons, rods, crank, the whole rotating assembly would be matched and I would think would work without the angle issues you cited. Man, my rag top would be a lethal sleeper then.....

The machinist likes Eagle H-beam rods. He convinced me to abandon the thought of reconditioning my antique rods with ARP rod bolts.

As for compression, I really would like to keep it between 8.75:1 and 9.0:1. If it is higher than that, then the purpose of what I'm trying to achieve is all but defeated. I might as well get the Sealed Power 10.1:1 slugs from Rock Auto then and create a still to make 98 octane gas.

Now I'm kind of worried the machinist may not know the difference between a 389 and a 400. I will have to explain that using 400 style pistons with my old #77 heads is not a direct fit. I should contact Ross, but I want to wait until I find out how far my block has to be bored.

The challenge of rebuilding a 389 makes me wonder if I should build a different engine for my car if my numbers-matching 389 is a goner. I plan on selling the correct WT code 389 that's in my car now to help finance my engine project, but if my born-with engine is shot, I might lean towards switching to a 400 or even a 455.

But I really hope I can put my original engine back in my '65 GTO. I think what I have in mind for the original 389 would be a really neat upgrade for my car. Hopefully I will hear something from the shop next week.

Thanks PontiacJim.
 
#19 ·
Spotts is a very sharp, knowledgeable guy with a good reputation. I'll be using some of his parts in my rebuild.

PLEASE consider converting to screw in studs. 2 reasons: 1) They're just plain stronger, especially if you go to the larger 7/16's ones, which if you do 2) gets rid of the Pontiac 'bottleneck' (which is the point where they tend to break) and gets you into a truly adjustable system using poly-locks.

Which you're going to need If you're considering any sort of cam/valve train change that can easily also required different springs, machining on the heads to get the correct installed spring heights for them, etc.

I agree with what PJ says --- if your machinist can't adapt to your needs, wants, and how they relate to your budget then it's time to find a new machinist. That can be one of the most difficult and frustrating things about building a Pontiac --- all the people who "already know it all" and think they're "just like a chevy". They don't, and they're not. I know it's frustrating to have to wait and look and re-evaluate constantly, especially when you really just want your car done. But trust me, get this part "wrong" and any enjoyment you get out of having a completed car will be short lived at best, and you'll eventually wind up sorely regretting not taking more time to get it right the first time.

Bear
 
#20 ·
I agree with you Bear. I think I will have screw-in rocker arm studs installed. I actually have a set, but they are not brand new. I can just buy a new set and go from there.

Without knowing the situation with my engine, my preliminary cam ideas are either the Melling 068 clone, part number SPC-7, or maybe the popular Summit 2801 cam. My compression will likely be in the 9.0:1 range, so I need to consider that when selecting a cam.

I really am just trying to restore this engine more than hop it up. I think moving up a notch with a better cam is the extent beyond stock I am headed. I am going to get a set of the H.O. exhaust manifolds and I want to recurve the Delco distributor. Other than mods like the stronger Eagle rods and poly lock nuts for the rocker arms, I am trying to keep the engine correct. I am using the original iron intake and correct #3895S Carter AFB (500 cfm).

The majority of the changes from original is to allow the engine to live on today's fuel and no zinc oil. I also want to use some neat items like the BOP one-piece rear main seal and maybe the BOP one-piece rubber/steel oil pan gasket.

I hope this machinist can build this engine. The first thing I am going to convey to him, without insulting his intelligence, is to cite 389s are different than 400s in that a piston for a 400 isn't very compatible with a 389 cylinder head. I am willing to spend the money to have Ross make custom pistons for my application.

Maybe I will hear from the machine shop this week. And as always, I sure appreciate the input everyone has given me on this project.

I'll keep all you Pontiac friends in the loop.
 
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