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roller cam selection for my monte ss

4K views 37 replies 8 participants last post by  redbandit98 
#1 ·
Yes, i am the guy that you hate because I started another cam thread. So be i need some help here. :confused: Ive putting together a 355 chevy for my monte carlo ss. It will have 3.73 rear gears, a 2k to 2500 stall, ~9.2 compression with the 62 cc iron vortec heads im putting on it. The block is still getting worked over at the machine shop. My plan is to get the shortblock done, and install some "upgraded vortec heads" from scoggin dickey. They have the bigger springs and the valve guides cut down to accept up to a .575 lift roller cam. I was going to go with the "hot cam" kit, but read if i use the 1.6 rockers that come with the kit, i would have to mill out my pushrod holes due to cleareance. I dont want to do all that. Im looking for bolt on and go. I called comp and they suggested a xr282hr. I think that may be a bit much for what im wanting. It will be strictly a street driven car. I do want it to have some growl to it, but I also want it to have plenty of vacuum since i will be running power brakes, vacuum operated hvac etc.. After all of this, i think a good option would be teh comp xr276hr cam using a set of stock 1.5 rockers. A nice roller cam with a little thump but good street manners. I may be totally off, and if anyone has better suggestions, please let me know. Also, im not dead set on a comp cam, thats just what i have been looking at. I had a lunati cam take out a 4k dollar ls1 that i built for my trans am so im not to hip on them.

EDIT: I forgot to mention that this will be a factory roller style cam, not a retrofit. Not that it matters a whole lot i assume. I have a factory roller one piece seal block to work with.
 
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#3 ·
Thanks for the suggestion. It looks pretty mild, which is really what i NEED, but I WANT something nasty..haha cant have both though. I used to have a crane compucam in my old truck and i thought it was a nice cam. I may end up going with one like the one you listed. I had a comp grind cam , think it was like a 268h or something in another vechicle, it was on a 110 lsa and it had plenty of vacuum. It was in a huge truck with massive tires and it had enough to run the brakes..i dont know. :sweat:
 
#4 ·
The off the shelf Comp roller cams that end with the # 8 are NOT a billet core,they are made from austempered ductile iron.I would not use one of these,period.If you want a Comp peice,they can supply you with a billet core,but I beleive it is a special order.And one very important thing to remember,make 100 % certain you have the correct valve springs,and check installed height and open pressure and coil bind.A better pushrod is also a good idea.I see you had trouble with a Lunati,but their Voodoo line seems to be very popular.Here is the phone number for UDHarold,who designs cams,call him and he can recommend one for you.
Guy


Harold is working for Lunati again and is making new profiles getting in touch with him is hit and miss he posted yesterday that his number is (662) 562-4933. You will also need to set aside time for conversation if you get through
 
#6 ·
I think that you are on the right track with the HR282 from comp. I am not sure if you have used roller cams before so they may seem radical when they actually will drive very well. The faster ramp rates and longer duration means you don't sacrifice anything on the bottom while getting more on the top.
 
#9 ·
SSedan64 said:
Austempered ductile iron is superior to steel at any given hardness level.
http://www.aditreatments.com/background.php
Interesting,but of course any manufacturer is going to say that their products are the best.The austempered roller cam core is still inferior to a true billet core.Something else that Comp Cams doesent advertise is that they recommend different valve springs for the austempered versus the billet.This is because the billet core can utilize a stronger spring,which is a good thing when it comes to roller cams.
Guy
 
#10 ·
I not taking a shot with comp but I do have issues with them. Tech help is spotty some are spot on others just read from the book. You have to specify eveything with comp from billet to a everwear gear to the fact you need a small base circle came when you do a 383 stroker chevy. There has been some core issues which you can see in other threads. I have some very good experiences with Crower, great product very good tech help. The other one which some top engine builders in the NE recomended to me, which really turned me on was Bullet Cam. On tech is Dave Patridge and he knows his product inside out. I swear he must dream about cam lobes. Really analyzes the situation with some various cam options with his personal recomendation. After installing his cam my car roars and it is streetable too. So that would be my choice.
 
#11 ·
ok, this probably changes things a bit, so I may have to start over or go a different route. I got a good deal on some pistons (practically free and brand new). I figured for the price I could make them work. They are a federal h423ncp. That is a coated -10cc dish cast piston. They are putting the engine together now. Its a standard deck height 350 bored .040 over. According to the charts with the pistons, i get 8.9cr with the 64cc heads and 9.41 with some 58cc heads. Obviously, I think getting the 58cc heads would be the way to go. I now need to find some good flowing heads and a cam that will match it. I would stick to the vortecs but I dont think an 8.9cr would yield that much power and make me use a very small cam? If i could get decent power from that, I could use 87 octane. I just dont know how much power im leaving on the table if i did go that route. Im not very knowlegable in the calculations.
 
#12 ·
Simple really ... just buy a set of Chevy factory aluminum FAST BURN heads and the " Hot Cam " ... then add the 1.6 roller rockers. Chevy says 430 HP.

They really make a LOT of power. Your lower compression will reduce the numbers a little ... but it still will make good numbers.





I have two of them ... and I am well satisfied.
 
#13 ·
well, i called the engine builder just now. I asked him if he had started and he said no, so i told him to deep six the dish tops and put the flat tops in it. I am just going to call scoggin dickey, order the hot cam kit with some heads, have them do the machine work and call it a day.
 
#15 · (Edited)
well, its too late for that now. I went and picked up the short block the other day. I just told them i wanted the flat tops in them, didnt specify a part number. Apparently they didnt deck the block any and used the 345np cast sealed power flat tops. (.040 over) I have a super crappy dial indicator and stand, but i did measure it 3 or 4 times and .040 from the center of the piston to the deck height is what i come up with. Does this sound right? I know its not good as ive read .050 total with gasket is where i need to be. What can i do to combat the issue short of installing new pistons? I havent bought heads or cam yet, can I have the heads milled some and use a thinner head gasket? Also with the cam, does this mean i will need to run a smaller cam since the compression wont be as high? Im not super worried about it as its just going to be a street engine, but I would like to do the best with what i have since its apart and i havent bought the top end yet.
thanks
 
#18 ·
redbandit98 said:
well, its too late for that now. I went and picked up the short block the other day. I just told them i wanted the flat tops in them, didnt specify a part number. Apparently they didnt deck the block any and used the 345np cast sealed power flat tops. (.040 over) I have a super crappy dial indicator and stand, but i did measure it 3 or 4 times and .040 from the center of the piston to the deck height is what i come up with. Does this sound right? I know its not good as ive read .050 total with gasket is where i need to be. What can i do to combat the issue short of installing new pistons? I havent bought heads or cam yet, can I have the heads milled some and use a thinner head gasket? Also with the cam, does this mean i will need to run a smaller cam since the compression wont be as high? Im not super worried about it as its just going to be a street engine, but I would like to do the best with what i have since its apart and i havent bought the top end yet.
thanks
You should check the deck height with the indicator close to the edge of the piston not the center.
 
#19 ·
Since it seems that you are building a bit of a performance engine,ditch those pistons and get ones that sit in the hole very little,say 0.005,use a composite gasket,say 0.035 or so,and this will give you close to an ideal quench area,which is anywheres between 0.050-0.030,(more or less).
Guy
 
#20 ·
i could re check the height and the reading would be a little different. Its still going to let me know that I got the "rebuilder" pistons and they are .020 down. That was the reason for me checking it to begin with. This, after i read all about it 3 days after the shortblock got home. :( I really dont want to change the pistons even though I know that would be the best solution. How much power I am leaving on the table if I was to just run with the current pistons with the smallest composite gasket (say a .020-.025) I could get ahold of? Also would having the heads milled help any?
 
#21 ·
redbandit98 said:
i could re check the height and the reading would be a little different. Its still going to let me know that I got the "rebuilder" pistons and they are .020 down. That was the reason for me checking it to begin with. This, after i read all about it 3 days after the shortblock got home. :( I really dont want to change the pistons even though I know that would be the best solution. How much power I am leaving on the table if I was to just run with the current pistons with the smallest composite gasket (say a .020-.025) I could get ahold of? Also would having the heads milled help any?
Milling the heads wont help the deck height. It will reduce the chamber size of the head. With the pistons you have now & 64cc heads I get 9.25CR. With 58cc heads I get 9.85Cr. Thats using a GM .028" gasket. But the quench/squish is .068", not good. You could pull the rotating assembly back out and have the block decked .020". The pistons you have come with 1.550" compression height, factory is 1.560". If you deck the block .020" & use the .028" gasket with the 64cc Vortecs you'de have .048" quench/squish and 9.66CR. Pretty good actually.
 
#22 ·
yes, i know milling the heads wont help the deck height, but i thought it may help out some. So bacsically the ONLY option is to have some different pistons installed or deck the block? I will try and see what I can come up with on it. I will ask again though since I have no idea. If i left it the way it was right now with the .028 gaskets will it run decent? By decent i mean will it work for a street motor with a decent size cam. I know it will hurt performance but how much are we talking about here?
 
#24 ·
If you want an inexpensive stock-type hypereutectic flat-top that's the correct height, the Speed Pro H631 costs maybe $50/set more than the H345 that's probably in it now. KB makes a couple of similar pistons (KB-120 & KB-228), but they're a little more expensive, around $200/set.
 
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