Dammit summit.......Dammit

[jeepsr4ever]

A nice fresh rebuilt 401 grenaded by a bad cast summit camshaft...roached bearings...dead dizzy gear...bottom of the dizzy chewed up.



They are getting a call tomorrow and a written letter with pics of all the damage.



Jeep still jumped a car though :?: even though it was knocking

[RustyJeep]

oh, this makes me very confident in the cam I have on the UPS truck.... :shock: :roll:

[jeepsr4ever]

was it a 8600 or 8601?

[Dusty]

I am sorry to hear that it cam apart on you like that. :(: I'd be frickin fumin and i imagine you are. A friend of mine from Vacaville has a Golden Eagle witht a new 304 that had a 8600 cam from summit that was cast improperly and roached the same way 6 moths after putting it in. Its been parked since March because of that too.

Summit gave him the :fist: for the most part and actually until recently he thought maybe it was an oiling problem that casued the gears to strip like that. more recently he discovered the problem was more involved and could be blamed on poor manufacturing.


Good Luck
Dusty

[tufcj]

I've been hearing some rumblings on the AMC Forum also. It seems in a effort to minimize machining, some of the lobes are cast too small, and the lobe surface isn't fully machined. I've heard of some returns. Check the lobes closely. :idea:


http://cgi.amcforum.net/cgi-bin/yabb/YaBB.pl?board=Engine;action=display;num=1086178935

Bob.

[Redemption]

lets just say summit has dropped out of the race for my cam choice.

[RustyJeep]

was it a 8600 or 8601?
It's the 8601.... :roll:

[FrankNB]

What else then??? I've checked the IFSJ forums, and that's pretty much what they all run over there... They mention that the Edelbrock is too mild...

[jeepsr4ever]

I am oging to run a 8600 in a 401 we have sitting here, if its bad the cam plug we are fabbing up withh keep it in check :wink:

[RustyJeep]

Looking at my 8601 sitting here, some of the cam lobes are still in "cast" form....making them rougher than a cob. I do believe these are all supposed to have a "machined" finish, eh? I am not going to use a summit stick....I am looking other places now.

[rollen dean montoya]

i generaly use crane cams but did use a trw cam on a buick 455 i installed
in a 67 firebird and had no problems. used crane cams in my other rebuilds(71 eldorado 500 v-8, 77 formula firebird 403 olds v-8, and a
friends 87 buick gnx 231 v-6 turbo). with shoddy quality control summit
needs to be stricken off the list on where to get parts!
later, rollen :lo1l:

[JMSII]

I have heard that Reed Cams are really good for AMC applications. I have not tried one personally, but a lot of AMC race guys like them.

Just my two-cent's worth.

[cjmike67]

I have run nothing but comp cams and have been very happy with them . I have no complaints about the product at all! :t:

[BRAD ARTHUR]

i done got the 8600 cam, its installed and just started the motor last night , runs good so far. purchased the cam begining of june. when did these bad ones start to pop up? followed jeeps forever suggestion, was going to go with the edelbrock. is there any thing i can check in preventive measures?

[rollen dean montoya]

1st look at the finish on the lobes. if ANY are unfinished(ruff) then
return and go with another bumpstick from comp, reed, crane or any other reputable company. just my opinion.
later, rollen :lo1l:

[jeepsr4ever]

Well I found the problem

the relief holes in the back of the cam were blocked by flashing and one summit cam we have here has no relief holes.................dangit, do I have to go through everything

[rollen dean montoya]

you might have to. i look at the bumpsticks before i walk out of the parts house. picked up a trw for the 67 firebirds 455 and it had a flaw. the #4
cam lobe was not polished correctly and trw happily shipped a new one to the house no charge. it also came with a hand written apolagy from the
inspector who missed it. but that was in the 70's.
later, rollen :lo1l:

[clarance49]

was it a 8600 or 8601?
Hey MC
I purchased a Summit 8600 cam this year on your recomendation for my 304 which is now rebuilt and ready to go. Are these cams any good or not? :oops:

[Mudrat]

Hey MC I purchased a Summit 8600 cam this year on your recomendation for my 304 which is now rebuilt and ready to go. Are these cams any good or not? :oops:

I can't say, but I can say 'don't shoot the messenger'. Summit has been a Name for years and (usually) has good stuff. I've gotten stuff from them for years with no problem. But I don't think they make their own cams, but contract out to their their specs. My guess from this thread is that they don't QA 100% of their products.

Mudrat

[clarance49]

Hey MC I purchased a Summit 8600 cam this year on your recomendation for my 304 which is now rebuilt and ready to go. Are these cams any good or not? :oops:

I can't say, but I can say 'don't shoot the messenger'. Summit has been a Name for years and (usually) has good stuff. I've gotten stuff from them for years with no problem. But I don't think they make their own cams, but contract out to their their specs. My guess from this thread is that they don't QA 100% of their products.

Mudrat
Hi Mudrat, I am not going to shoot the messenger. I talked to my engine builder and he said during the rebuild every thing worked as it should, he also said that a lot depends on how the cam is broken in.After all, he has to guarantee the engine! The guy whom rebuilt my engine does racing engines. :t: (Speery Engines Cedar Rapids,Ia)

[Mudrat]

Hi Mudrat, I am not going to shoot the messenger. I talked to my engine builder and he said during the rebuild every thing worked as it should, he also said that a lot depends on how the cam is broken in.After all, he has to guarantee the engine! The guy whom rebuilt my engine does racing engines. :t: (Speery Engines Cedar Rapids,Ia)
Roger that.

HEY!!! MC... did you figure out what happened?
Curious minds want to know :oops:

Mudrat

[clarance49]

Hi Mudrat, I am not going to shoot the messenger. I talked to my engine builder and he said during the rebuild every thing worked as it should, he also said that a lot depends on how the cam is broken in.After all, he has to guarantee the engine! The guy whom rebuilt my engine does racing engines. :t: (Speery Engines Cedar Rapids,Ia)
Roger that.

HEY!!! MC... did you figure out what happened?
Curious minds want to know :oops:

Mudrat

MC, Curious mind still want to know what happened. I sent an E mail to Summit and have had no replies yet. :!:
C49

[jeepsr4ever]

no oil relief hole in the back of the cam....

[clarance49]

no oil relief hole in the back of the cam....


Mc, I finally got a reply from Summit on my SUM 8600. I thought this guy was going to go postal with his reply! He told me to beware of chat forums, Geeeeez I thought I we were talking about Jeeps not just a chat room. :razz:
Summit definitely does not want to have any blame placed with thier cams. :!: He also said AMC people do not want to change from bridge pivot rocker arms to the adjustable which is required according to Summit this list goes on and on so think I will get off of my soap box. The more I read his E mail the more Po'd I get. :roll:
I trust your opinions and the work you have done for me now and in the future. =D>
C49

[jeepsr4ever]

Summit wants to cover their butt cant hardly blame them for that....HOWEVER telling us that it isnt the camshaft when it is and also not standing by their product will and has turned off alot of their customers. These "chat rooms" are where people of unbiased opinion can discuss their experiences. Summit is aware of Bulltear and so is comp cams and they both have members here. These companies do have great products but even with a small percentage of scrap that makes it out somebody will post their experience and we should not be silenced for having spoken our minds.....


-MC

FWIW I believe both of the cams are about equal in quality :mrgreen:

[79cj7duner]

somebody will post their experience and we should not be silenced for having spoken our minds.....

I think It's called the first amendment...????

I'm running an edelbrock in my 304 and I can't complain a bit about the cam.

My $.02

[jeepsr4ever]

haha yeah that cam is definately a good choice for a 304 :t: It was designed for use in a 304 :idea:

[John N]

Can we re-address one of the earlier questions? What's a good substitute for the 8601? I'm about to build a 360 for my Scrambler and thought that was the right choice.

[MC]

Tell me about your drivetrain John.

[John N]

It's a Jeep Scrambler, has a weak remanned 360 in it now (low miles), Howell FI on an Edlebrock Performer, DUI ignition, stock dog leg exhaust manifolds into a Y pipe single exhaust. Running a TF999 automatic, Dana 300 transfer case (new one on the bench going in soon with 4:1 gears, clocked, twin sticked), Dana 44 axles front and rear with 4.09 gears (ARB lockers). Tires are BFG M/T 33's, might go to 35's eventually.

The engine I'm about to rebuild is a (supposedly) '72 360. The head #'s are 3212993-1 with the individual rockers (are these studs pressed in or screwed?). The bores are in decent shape, but haven't been checked out completely. I can't find anyone with specific AMC knowledge in my area to build it, so I have to, pretty much, specify what I want....I'm looking for low end grunt off idle for off-road and decent street performance up to 5000 (okay I'll take up to 4500 rpm). I figure 300 hp should be possible on regular gas. Am I asking too much? All my friends are Chevy and I don't want to......
Thanks....

[73hornut]

Those rocker studs are screwed in and don't need any guide plates for the push rods. I would drop in a 270 comp cam and lifters. 3/8 roller rockers and chevy studs. Replace the valve springs with some crane dual springs. New valve retainers and locks. Edelbrock shorty headers, and 2-2 1/2" exhaust. Should wake it right up!

[John N]

It's a Jeep Scrambler, has a weak remanned 360 in it now (low miles), Howell FI on an Edlebrock Performer, DUI ignition, stock dog leg exhaust manifolds into a Y pipe single exhaust. Running a TF999 automatic, Dana 300 transfer case (new one on the bench going in soon with 4:1 gears, clocked, twin sticked), Dana 44 axles front and rear with 4.09 gears (ARB lockers). Tires are BFG M/T 33's, might go to 35's eventually.

The engine I'm about to rebuild is a (supposedly) '72 360. The head #'s are 3212993-1 with the individual rockers (are these studs pressed in or screwed?). The bores are in decent shape, but haven't been checked out completely. I can't find anyone with specific AMC knowledge in my area to build it, so I have to, pretty much, specify what I want....I'm looking for low end grunt off idle for off-road and decent street performance up to 5000 (okay I'll take up to 4500 rpm). I figure 300 hp should be possible on regular gas. Am I asking too much? All my friends are Chevy and I don't want to......
Thanks....

How is this for a substitute for an 8601? It's from Engle:
P/N 5054-H Grind # K-54HYD
Valve Lift .501" & .501"
Adv. Dur. 260¬? & 260¬?
Cam Lift .313" & .313"
Dur. at .050" 214¬? & 214¬?
Lobe Separation 112¬?
.904" Lifter profile for low & midrange torque for milage & towing power from 1200-5200 R.P.M.

[redneckjeeper]

well gents i have the summit 8601 cam installed in my 360 that is in my 73 cj5 for about a year now and have not had any trouble what so ever out of it, sounds to me that someone did not do a very good job of inspection before putting parts in motor, I have been working on these things since 1967 and in all those years i have learned to inspect everything before installation of any part. I am not knocking on anybodys door step but you must check every part first and then more than likely you will not run into trouble.. Just my 2 pennies worth.. :t:

[eight]

I agree. From what I can gather, the problems are flashing in the oiling holes, and unfinished lobes. Both can be easily inspected. And if both are fine, the cam should be fine. But summit's not known to make the best cams anyway, they're decent and cheap.

John, that cam sounds more like a substitute for a K8600. But I think it will work great for what you want. A K8601 really is a big cam, its got 224 on the intake. Not gonna run good real low in a 360.

[AMX69PHATTY]

:idea:

Anyone ever looked at Lunati Cams ?
Building a 367 for my '69 AMX and used the Lunati #31702
.496 / .496 - 228 / 285 IN - 235 / 300 EX
but I have a 3000 stall 10 inch and 3.73 Gears and not after low end.

May I ask if you could elaborate on the Oil Relief holes in the back of the cam, how they should look, and what they do / how they work ?

--> Went and looked at the cam, are the 2 axial relief holes in the aft most journal there to allow any oil that may get behind the cam inbetween it and the freeze plug in the back of the block to run back into the block cavity and therefore not build up pressure and shift the cam forward ?

And about the Screw in Rocker Studs, I use the 7/16 size, Crane Roller rockers, and Poly Locks. I found that the Chevy Studs were too short and the Poly Locks were only on a couple threads at the top when the rockers were properly adjusted. Replaced them with slightly longer 7/16" studs from MOROSO that are for the 351 and Boss 302 Ford, and now that solved the problem and now have plenty of Poly Lock Thread engagement when properly adjusted and the Jam Set screw doesn't really stick out but a thread or two. MOROSO Studs #67820.

And it seems AMC's always have the tip of the Valve stem flush or below the top surface of the retainer. I messed around with different retainers and locks to get the Valve stem tip to just slightly extend above the top surface of the retainers. Anyone else noticed this and/or made this "adjustment" ??

For Valve Springs I use K-Motion Duals for years and have had good luck with them. Anyone else ever looked at K-Motion Valve Springs ? My understanding is they are a small family owned bussiness in Indiana, and I always try to support the small independent when I can.

Some thoughts and questions for what it's worth.
Thanks in advance for same.
Now if I can just get motorvated and finish buildin' this motor .......
Plenty of time now since I got fired on July 19th, there's just this money thing....
#-o

[giz]

I did't run the summit cam but had enough problems with my comp 268 the first cam sent out was missing the front keyway for the dist gear so they gladly replaced that the replacement cam had #4 journal +.01 oversized that was enough on new cam bearing to spin it. I hadn't miked the cam journals first but since it was tighter than the max size i called comp they said had I not already run it they would have swapped it out.all I wanted was a replacement i figured that the rest of the engine damage was my fault for not micing the cam,but no such luck I understand quality control isn't perfect but a little customer service would go a long way towards keeping a customer. I feel comp let me down and I can't recommond them but replaced it with a ENGLE cam and would recommond them.

Giz

[Goose]

Well Giz, Im with you.. There is a little thing called quality control..sheesh

[SHARPMACHINE]

Sorry to drag this thread back to life, but it has alot of good info... Could anyone show a pic. of a 8600 summit with transfer line problems?

I run a stock 8? 360 tf727, 3:55, maybee soon 4:11 gears and want to add a cam and junk yard tbi. Jeep is used for dunes, trails, mud and street (real multi-purpose vehicle hehe).

I would would like to know how to inspect the oil transfer lines when I get one. I do understand how to inspect the grind of the lobes.

thanks

[SHARPMACHINE]

any ideas of above post??

thanks :lo1l:

[AMX69PHATTY]

I'm no expert
in rear most journal axial holes free and clear to relieve oil from between cam butt and freeze plug
in front most journal a groove all around and/or a groove in bearing
one radial hole feeding one axial hole through front journal face
this hole lines up with a notch in aft face of cam sprocket, critical
chamfer around aft side hole of cam sprocket
clean second "keyway" through cam sprocket, eccentrc, dizzy
clean small oil holes radialy through dizzy
flat smooth heavy cam bolt washer seals against dizzy
cam bolt not to long as to prevent bottoming in cam

is this what you're talkin' ?

[46flattie]

Thanks to this post and a few others regarding the Summit (or anybody's) cams, I did a little more cam inspection than usual. Anyhow my new K8600 looks good regarding lobe surface, oiling holes and front journal grove, etc. (FWIW: I believe Summit indicated to me that Crane grinds their cams.)

One question though, at the edges of the lobe are sharp edges. (Not burrs, and not on the lobe surface, but rather on the side of the lobe at the 90 degree intersection of the ground surface and the cast lobe.) Should a guy carefully chamfer this?

[SHARPMACHINE]

Thanks to this post and a few others regarding the Summit (or anybody's) cams, I did a little more cam inspection than usual. Anyhow my new K8600 looks good regarding lobe surface, oiling holes and front journal grove, etc. (FWIW: I believe Summit indicated to me that Crane grinds their cams.)

One question though, at the edges of the lobe are sharp edges. (Not burrs, and not on the lobe surface, but rather on the side of the lobe at the 90 degree intersection of the ground surface and the cast lobe.) Should a guy carefully chamfer this?

Sorry to answer so late, but this is important.

Should not be necc. to chamf., but make sure the oiling holes are thare. It might be a good idea to run a pipe cleaner down the holes as well to make sure thare is no sand still in the cam.

[46flattie]

Thanks for the reply. Looking back it seems like kind of a dumb question, but I was being pretty anal when I assembled the motor, especially w/the cam due to some apparent issues others were having. Fortunately, I've never (knock on wood) had any cam issues in any of my motors.

[rockjeep]

my summikt 8600 cam in my 304 lasted about 8 hours

[73hornut]

Does anyone take the time to thoroughly clean the cam, before lubing and installing?

[Mudrat]

Does anyone take the time to thoroughly clean the cam, before lubing and installing?
Define "thoroughly clean" . . . shooting brake cleaner though the oiling holes and washing the outside down count :t: #-o

[tufcj]

I always run mine thru the solvent tank, rinse thoroughly, and blow dry with compressed air before applying the assembly lube. I do the same with cranks and rods. Engine blocks get hit with soap/water and pressure washer, all passages cleaned with brushes. Everything always has to be clean.

Bob
tufcj