ok...i know that there is more HP to be found using the roller cams such as the "hot cam" and the comp cam "xr" series....

since i'd like to keep my noisey gear drive, i'll prob stick to hyd cams...
if i use the 274xe instead of the current 268xe on my 350HO w/vortecs, will i see/feel any HP gains?

i don't want to give up the streetability of the 268xe...power brakes, descent idle...for my a/c etc.

input will be appriciated!



[This message has been edited by czar (edited 07-12-2002).]

I've run both cams (XE274 and Hot) with vortecs. The XE version ran 13.5 @ 101. As soon as the car is finished being painted, I'll post the results of the HotCam setup. Seat of the pants feels a lot stronger mid-range with the roller... Setup of everything else on the car has remained the same.

------------------
Bill Burke

'80 Camaro RS
ZZ4 Vortec w/ Hot Cam kit TH350, 3.73
'68 Corvette L-79
41K original miles
'02 Corvette convert.
Torch Red/Black

'68 Corvette L-79 (http://www.chevelles.com/showroom/68vette.jpg)
'80 Camaro RS (http://www.chevelles.com/showroom/Bills80CAMARO.JPG)
'02 Corvette (http://www.chevelles.com/showroom/CorvetteFront.JPG)

czar,
Funny thing you brought this question up... I was talking about this exact thing with my speed shop guy today! I was surprised he had some nice things to say about the vortecs (you just gotta know Gary to understand that statement...) and said those would work good on the 327 I'm planning to rebuild. I also asked him about the XE274 cam and the GM HOT cam...

FYI, check out the prices on getting ALL the parts and work done to convert to a roller motor for the HOT cam and it then becomes a much easier choice!

let's just say he didn't have many favorable things to say about the HOT cam and said the XE274 would be a lot better and pick up and easy 30 hp over the HOT cam. I know there are some guys here that like the HOT cam and that's fine, I don't want to start an arguement, just passing on some opinions.

So, to kinda pull my wholeplan together, it will be a 68 327 .040 over, vortec or Pro Topline heads, XE274 cam, Stealth or Super Victor mani (depending on the heads I go with...), headers, TKO 5-speed, 3.42 posi rearend. This will be in my Nova, so hopefully will work ok. This is my daily driver, so I can't get too radical with it!

edit- Bill, please keep us posted on the results of the new motor with the HOT cam!

Good luck,
Bill C.


------------------
Bill C.
Colorado Springs, CO

68 Camaro... someday!
71 Chevelle SS
70 Nova

[This message has been edited by BC (edited 07-12-2002).]

Heya BC http://www.camaros.net/forum/wink.gif

I know Gary too...I've noticed if he doesn't sell it himself, he doesn't like it. http://www.camaros.net/forum/smile.gif

Anyway, I'm a big fan of the HOT cam, and IMO, there's no way the flat tappet 274XE could compare with the roller HOT!

It does everything well, including good idle vacuum at this altitude.

------------------
Don~ ZZ430DropTop (http://hometown.aol.com/zz430droptop67rs)
~~~~and~~~~
70 RS/Z28 (http://hometown.aol.com/performancespecs)
67 RS/SS Convertible, 70 RS/Z28

The 268 will make better low end power than the 274. FWIW, Dyno 2000 simulations say that the bottom end power loss is bigger than the top end power gain.

BC,

My new 355 (hopefully will be firing next week!) has an XE274 and the Pro Topline 180cc heads. The heads appear to be top quality and the flow numbers are pretty impressive.

There is no conversion costs to run a Hot LT4 cam (or any other GM Roller for that matter) in a pre 86 block. I'm running the Hot Lt4 cam right now in a 79 non roller block. The only thing you need to do is get the Cam Retainer plate (which comes with the GM double roller timing chain for about $50), cut the ears off it, and use it as a spacer behind the timing gear.

You need to use a cam button and the only one that will fit is the kind with the removable spacers and bearing. It also has to be installed backwards, so the the small end that is normally against the timing cover is in the timing gear hole. This is because the timing gear bolts circle is smaller on a GM post '86 roller than on the Retrofit rollers. I also had to use Socket head bolts instead of hex head bolt to attach the timing gear so the heads would clear the edge of the cam button. Putting the cam button in backwards is not really that bad as it spreads the load out on the timing cover, over about twice the surface area.

The hot LT 4 cam costs about $175 from Scoggins Dickey, the timing chain cost me 49.95 from GM Performance Parts, the cam button cost me 4.95, the three 5/16" Socket head bolts cost me about $2.00.

Since no matter what cam you use you will need a set of retrofit rollers that cost is a wash, and is equal to or better than the cost of all the other parts.

So all in all it is probably a hundred bucks cheaper to use a GM cam instead of a retrofit cam. And as a side benefit you don't have to run a bronze timing gear on your distributor.

I've had some issues with this swap but they are due to the cheap offshore clone roller tipped rockers I bought. I managed to screw up some of the retainer grooves in my valves because the edges of the rockers were actually pushing down on the spring retainer instead of the valve stem. So this fall the heads come out for a new set of valves. But other than that the Cam is running just fine.


------------------
Mark Canning
1969 Indy Pace Car
350/300HP RPO Z11
My 69 L48 - 350/300HP Engine (http://www.townisp.com/~markcanning/camaro/transparent%20air%20cleaner3.jpg)

I say don't worry about the bottom end power loss if you use the Vortecs. I used the XE274 and just swapped to a Super Victor and the bottom end is more than adequate. I do have 3000 stall convertor. With the 2500 stall it was a much different engine. The convertor is a deciding factor on the cam. Less stall less cam.

------------------
GMPP 350 330hp Comp cam XE 274 Modified Vortecs Edelbrock Super Victor Manifold Holley 750DP D.U.I HEI Distributor B&M 3000 Holeshot Turbo 350 3.73's Eaton Posi

billscamino,

i'll anxiously await to hearaobut your ets!

bc,

i like the 5-speed on your set-up. let us know what you decide to do. ya see, my concern was if i stick with hyd's...will the 274xe be much better/stronger then my 268xe?

boddleproof,

i wanna hear how your rig runs when ya get it going too!

marc,

i have a roller block...no conversion would be needed....i just wonder how durable roller cams are....i've had hyds that ran 180,000 hard miles...

mello,

i still wanna know how your set-up runs or dynos....

thanks for the input!

Hey Don, Yeah I know Gary is a little biased... just gotta take the info for what it's worth! Have you installed the HOT cam in any of your cars?

Mark,
Well, I realize there are no actual machining changes that need to be made, but doing the roller bottom end versus the normal 'flat tappet' is quite a bit more expensive from what I've seen! I thought I once saw a complete HOT cam kit that came with the cam, lifters, retainers, pushrods, etc to do the conversion easily, but now I can't seem to find it! The roller lifters seem to be the big-dollar item in this whole swap... what lifters are you using? I guess I'm having a hard time with your numbers on the costs of the cams and lifters... the XE cam with lifters is about $175 and the HOT cam alone is almost $250! Then I still have to buy the lifters! I realize the rockers arms are about a wash...

czar,
thanks for the note on the 5-speed, still got a ways to go before that happens! I first need to get all the manual parts to do a manual tranny, then worry about the tranny! For now, the 700r4 will have to suffice!

Thanks for all the help guys,

Bill C.

The HOT cam kit comes with the cam, valve springs (LT-4), retainers, locks, spring shims, and 1.6 ratio aluminum bodied self-aligning roller rocker arms for $499.95. this is as listed in the latest catalog i received from Scoggin-Dickey. The cam by itself is listed at $175.50.

The GM hydraulic roller lifter kit comes with the lifters, lifter guides, guide retainer (spider), retainer bolts, and washers. This is listed at $192.50.

I am almost ready to drop in my Vortec-HOT cam 355. I have decided to go with the stamped self-aligning rocker arms with a ratio of 1.5 for the time being. This will give me a lift of .492. Maybe later I'll change to a roller rocker.

If you already have a block that is ready for the roller set-up I would definitely go that route. Where you start to run into more dollars is when you have to buy the retro-fit roller lifters. They are expensive and I have also heard reports of them being on the self-destructive side.

I was refering to the price difference of a GM cam vs the price of installing an equivalent Comp or Crane roller. There is no way you can compare the price of a roller vs a hydraulic or solid flat tappet cam. But then again you get what you pay for. I was just trying to tell those that worry about needing a post 86 roller block to run GM performance cams that they cams will work just as well in a non roller block, if you get the right parts. And yes the Retrofit rollers are by far the biggest cost. They run between 250 and 350 bucks depending on where you get them. GM roller lifters are much cheaper if you have a roller block and the spider setup in the lifter valley. The minimum price to install a Hydraulic roller in a non roller block is probably right around 600 bucks for everything, assuming your not doing anything to the heads (springs, machining guides etc). Which by the way Vortecs can only support about .420 inch lift in stock form, so either of these cams are not useable without maching the guides.

Heres two identical engines one with an XE 274xe, on with a Hot Lt4 Roller. Both are about 10 to 1 compression 350s, with a dual plane intake and 780 carbs, small tube headers with mufflers. (Actually I screwed up and the XE is 10.5:1 and the roller is 9.72:1 compression.) Both have the cam advanced 2 degrees. The rollor consistantly beats the XE by 30 HP all the way up to 4500 rpm, and by 90 ft lbs up to 4000.

http://www.townisp.com/~markcanning/camaro/GCS0013.jpg

The LT4 cam is the graph with just a line, red is HP, Blue is Torque. The XE274 is the line with the blue diamonds on it. The table on the left is for the LT4 cam engine.

Heres the link to the Hot LT4 Cam at Scoggins Dickey, 175.50 for the cam.

www.sdpc2000.com/cart.asp?action=prod_detail&catid=989&pid=1087 (http://www.sdpc2000.com/cart.asp?action=prod_detail&catid=989&pid=1087)

------------------
Mark Canning
1969 Indy Pace Car
350/300HP RPO Z11
My 69 L48 - 350/300HP Engine (http://www.townisp.com/~markcanning/camaro/transparent%20air%20cleaner3.jpg)



[This message has been edited by Mark C (edited 07-13-2002).]

i have the HOT cam kit and unported vortec heads on the late model 355 in my Nova- and love it. does everything well. it starts nice, has snappy throttle response, strong mid range and top end power to about 6500- but goes past 7000 if i want- and gets 16 mpg if i drive her right.
the main reason i even got the HOT kit was because my cousin worked as a parts guy at a Chev dealer, and i get it for dealer cost- think it was $400 or so for me. i bought a set of new Crane stock replacement roller lifters from Jegs for $170 or so, and used the GMPP single roller timing chain setup. I'd do it again in a heartbeat for everything but a tow truck.

------------------
1971 Nova(looks like 69 camaro from underneath!)
355sb, vortec heads, HOT cam,T-10 tranny, 3.70 gears 16X8" IROC wheels. 12" Corvette brakes on the way.
see pics here http://community.webshots.com/user/novaderrik

BC, yeah, I've been using the HOT cam for a couple of years now in the 67.

I agree with novaderrik, it does everything well.

Mild to wild.

A friend has a XE274 in his 383, and it runs great...it just has the normal low vacuum, aggressive ramp noise, lumpy idle.

------------------
Don~ ZZ430DropTop (http://hometown.aol.com/zz430droptop67rs)
~~~~and~~~~
70 RS/Z28 (http://hometown.aol.com/performancespecs)
67 RS/SS Convertible, 70 RS/Z28



[This message has been edited by ZZ430DropTop67RS (edited 07-13-2002).]

Well, Sounds like the HOT cam is a good way to go! Is there any machine work that need to be done to the early block to make the retro-roller lifers work, or is everything I need included in the kit? What need to be done to the heads to make the new springs work with the HOT cam?

Mark,
I'm just trying to figure out exactly what nneds to be done to put the HOT cam in an early block. I have the 68 327 in the garage and it has already been bored .040. The guy who gave it to me said it was knocking a little, but I found no evidense of this when I took it apart. It only had several thousand miles on it from what it looks like, so just needs to be freshened up and ready to go. It did have some 305 heads that I already got rid of, so I need new heads anyway. It supposedly had an LT1 cam in it, but no markings anywhere and I'd like something with a little more power. From what a lot of people have been saying, I'm really looking hard at the vortecs and putting in the HOT cam, I just want to know what is all involved up front so there are no surprises!

Derrik,
Have you got any dyno or track results from your setup? Sounds like it might be real similiar to what I'll end up with and since this will be going into my Nova...

Don,
So when you gonna let me test-drive the 67 so I can see if I like it?? http://www.camaros.net/forum/wink.gif

Thanks again for all the help,
Bill C.

Czar
Yesterday chassis dyno in Cheyenne Wy. 6,060 altitude. 305Hp and 410lbs torque at rear wheels and at this altitude. Air/fuel mixture ran between 12.0-13.0 and thats with a 750DP 66 primary and 84! secondary jetting. Great throttle response and drivability. Docile in normal use great idle but an animal all out. I would love to have it at sea level

------------------
GMPP 350 330hp Comp cam XE 274 Modified Vortecs Edelbrock Super Victor Manifold Holley 750DP D.U.I HEI Distributor B&M 3000 Holeshot Turbo 350 3.73's Eaton Posi

i personally have never dynoed it, but CHP had that buildup just like mine a few months back, and i remember 410 horses or so. it got put in a 12 second Chevelle.
i have had it together for 2 years now, and have had zero problems with anything- but i got used to the power, so i need more. looking at AFR 190 heads and a performer RPM Q-jet intake. desktop dyno tells me closer to 500 horses with that, and no loss of torque. and, yes, i know DD is a bit optimistic, but even 450 would be good, along with the weight loss going from iron to aluminum heads.

------------------
1971 Nova(looks like 69 camaro from underneath!)
355sb, vortec heads, HOT cam,T-10 tranny, 3.70 gears 16X8" IROC wheels. 12" Corvette brakes on the way.
see pics here http://community.webshots.com/user/novaderrik

[This message has been edited by novaderrik (edited 07-14-2002).]

novaderrick,

you got a strong combo going...will your nova hit 12's? you might be the on to convince me to go roller.....

mello,

awsome numbers...especially at 6000+ feet!!! i'm curious how your combo would do in the track...ya gotta run soon!

bc,

i'm jealous....wish i had the 700r like you & looking into the 5-speed. man, that will be the ultimate control!!!!

thanks for all the input guys!!!


[This message has been edited by czar (edited 07-14-2002).]

To put a late model GM roller in a pre 86 block you need:

1) A GM Roller Cam. Note that the bolt circle on the nose of a GM Roller Cam is smaller than a retrofit, or flat tappet cam thus you need item 2.

2) GM Performance Single Roller Timing chain Kit. PArt Number 12371043 $49.95 This kit comes with the chain, both crank and cam gears, two different cam retainer plates and the bolts for the retainer.
3) Crane anodized Aluminum needle bearing camshaft button, Summit part number CRN-99164-1 $9.95

4) Retrofit Hydraulic Roller Lifters Your choice of manufacturer and brand, roughly $350.

5) 7.290" Long Valve Pushrods, your choice of manufacturer roughly $50.


Make sure you get a Camshaft with a fuel pump lobe if you have a mechanical fuel pump. My selections in order of preference is the Hot LT4, the ZZ4, roller or the Ram Jet 350 cam.

Hot LT4

Duration @ 0.050" 218 / 228
Lift: 0.525" / 0.525"
Lobe Separation: 112
RPM Range: 1500-6000

ZZ4 Cam
Part # 10185071
Duration @ 0.050" 208/221
Lift: .474"/.510"
Lobe Separation: 112


Ram Jet 350 Cam

Part # 14097395
Duration @ 0.050" 196/206
Lift: .431"/.451"
Lobe Separation: 109

This last one is supposed to be a real torque producer with a stock idle. I've got a brand new one siting on the shelf in my garage. It almost went in the car, but I went with the Hot LT4 (there is an LT4 cam as well)


The Timing gear kit comes with two different retainer plates, one for the ZZ2 and 3 style blocks and one for the ZZ4. The only difference is in the spacing of the two bolt holes. Take one of the retainer plates, cut the ears off it so that it looks like a large washer and use this as a spacer between the cam gear and the front face of the block. I also ground a set of 4 grooves into each face of the retainer to allow oil to get between the plate and the front face of the block.

Fit your cam button to the cam gear before installing it into the car. The button goes in backwards, Small end into the gear, large end against the timing cover. I had to open up the diameter of the center hole slightly to get the button to fit. Use a set of socket head bolts to attach the cam gear to the camshaft, since hex heads will hit the cam button. Insert the button into the hole and set you thrust just like a retrofit cam. I didn't do this but don't seem to have any issues with the cam walking. The GM Timing set does not have multiple keyways on the crankshaft so if you want to advance or retart your cam you will need to do it with offset keyways or cam bushings. Mine is installed straight up.

Everything else about the installation is the same as any cam swap. Some people say you need a fuel pump rod with the hardened end with a roller cam, but GMs cams are not the same billet steel as the aftermarket cams so I don't think one is necessary here. At least I didn't put one in, but anyone who feels one is necessary is welcome to do it. You also don't need a bronze distributer gear with the GM performance cams, the stock iron ones work just fine.

I'm also running some 1.6 roller tipped rockers that required new springs, but that is another subject. If you have pushrod retainer plates, make sure that you get NON-self aligning rockers, and that the pushrods do not bind in the retainer plates. Also make sure the roller sits on the valve stem and the arms do not touch the spring retainers at any point of the engine rotation, or you will be replacing valves.

My Hot LT4 is in and runs just fine, vacuum at 15.5 to 16" at 750 RPM, with just a slight lope. Much more power and better idle characteristics than my old 327/350 L79 flat tappet hydraulic cam. Keep in mind that my car is a weekend cruiser, The engine is essentially stock except for this cam and has the stock intake, 4bbl Rochester carb, and exhaust manifolds. It has not ever been to the strip since I've owned it and this cam suits me fine. It may be a bit to tame for someone trying to get into the 12's in the quarter mile. I'm not saying you couldn't get there with the right parts, just that my more or less stock setup won't.


------------------
Mark Canning
1969 Indy Pace Car
350/300HP RPO Z11
My 69 L48 - 350/300HP Engine (http://www.townisp.com/~markcanning/camaro/transparent%20air%20cleaner3.jpg)

Thanks so much Mark, that info really helps out a LOT!

Now I just need to win the lottery so I have some money!

Bill C.

Mark C,

I have a LT-4 Hot cam installed in my 355 that hopefully will be going in this weekend and I see that you say the stock iron distributor gear should work fine with this cam. I was under the impression that it required the GM "melonized" gear. I have an Accel billetproof distributor and was going to change the gear that was supplied with the distributor over to the GM piece, but if it isn't necessary I won't bother.