#1  
Old 01-23-2020, 10:43 AM
F ROCK's Avatar
F ROCK F ROCK is offline
Ultimate Warrior
 
Join Date: Jun 2003
Location: sicklerville nj 08081
Posts: 1,938
Default Newbie engine build questions.

I have a 455 block bored .030 with the cheaper sealed power forged pistons w/ flat tops.. (i'm not sure of the part #).
The block was not decked but my novice eye and a straight edge tell me they are all the way at the top.
I have unported 6X-4 heads that measured 92cc; and retain the stock valve sizes.
I have a 1972 iron intake and a Q-jet.

The online compression calculators that I have found produce a variety of results from 9.7:1 to 10.4:1.
No roller cam in the budget.
Car is a 1971 GTO, non A/C, 4 speed M20, 3.73 gears. I have another rear that has 3.08 gears, but the 3.73 is in the car right now.
The car has Ram Air d port iron headers and a 2.5 pypes system with street pro's and X pipe.
350-375 hp is fine as it's just a cruiser. street manners and reliability.

I had selected the ole melling spc-7 (068?) for the simplicity of retaining my stock valve hardware, and because of the horror stories w/ flat tappet cams.

I know this is a very small cam for this build but is it TOO small for a simple street machine?
I've been searching a lot on these forums and some say a cam too small can detonate and have tuning issues.


Last edited by F ROCK; 01-23-2020 at 11:30 AM.
  #2  
Old 01-23-2020, 10:52 AM
steve25's Avatar
steve25 steve25 is online now
Ultimate Warrior
 
Join Date: May 2008
Location: Westchester NY
Posts: 14,632
Default

Your Pistons should have part number L2359F > .030 on the top, which would have a valve notch volume of 6.7 CCs.

The most commonly used Fel Pro head gasket has a volume of 6.4 CCs.


Does your Block have Intake valve chamfers on the deck surface?

Many blocks that came with 2 bbl heads did not have the chamfers but to nail down your
compression you need to know that and the deck clearance even if it's only .010"

If your shooting for a 9.5 compression then you need a total CC volume above the piston at TDC of 100 CCs by my math.

Basically with your .030" over 455 every change up or down of 5 CCs from 100 CCs will change your compression by 1/2 a point.

__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!

Last edited by steve25; 01-23-2020 at 10:58 AM.
  #3  
Old 01-23-2020, 10:57 AM
track73 track73 is offline
Ultimate Warrior
 
Join Date: Nov 2006
Location: Munster In
Posts: 1,504
Default

With that compression, carburetor and gearing set up, I'd go with a Ram Air 4 clone with Rhode lifters. I don't think the lifters are that noisy and the are built on Johnson bodies .If you are worried about noise, buy some Mega Flow Mufflers. The Springs aren't that expensive. Do the heads have screw in studs?

__________________
1979 Trans Am WS-6 .030 455 zero decked
flat pistons
96 heads with SS valves
041 cam with Rhoads lifters 1.65 rockers
RPM rods
800 Cliffs Q Jet on Holley Street Dominator
ST-10 4 speed (3.42 first)
w 2.73 rear gear

__________________________________________________ _______________________________

469th TFS Korat Thailand 1968-69 F-4E Muzzle 2
  #4  
Old 01-23-2020, 11:05 AM
F ROCK's Avatar
F ROCK F ROCK is offline
Ultimate Warrior
 
Join Date: Jun 2003
Location: sicklerville nj 08081
Posts: 1,938
Default

The engine is at the shop right now.
I don't think the pistons were in the hole at all but I didn't measure; I just put a straightedge on the top and looked for light.
As I have read, it's not uncommon for the '71 and up 455's to be at or very near the top?
factory 4bbl engine, YY I think. I didn't notice any chamfers at the deck.
yes, screw in studs.

  #5  
Old 01-23-2020, 11:37 AM
steve25's Avatar
steve25 steve25 is online now
Ultimate Warrior
 
Join Date: May 2008
Location: Westchester NY
Posts: 14,632
Default

With those 3.73 gears even though there a tad too stiff for a street 455 atleast you will be far less likely to have ping issues if your compression is a tad too high for that 068 Cam.
If your going over to 3.08 gears with more then a 9.2 compression then a bigger Cam will be needed.

__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!
  #6  
Old 01-23-2020, 01:37 PM
chiphead's Avatar
chiphead chiphead is offline
Ultimate Warrior
 
Join Date: Nov 2004
Location: Aiken, SC
Posts: 5,182
Default

I use this calculator, it accounts for ring back volume, gasket volume, etc.

http://www.diamondracing.net/tools/

When I put in a 6.7cc piston dish and a Felpro 1016 gasket,0 deck, 92cc chambers, I get 9.7 CR. Maybe a little less if pistons are .005" in hole. (hard to see without deck bridge)

Use a cam with at least 230* intake duration and 112-114LSA.

__________________
I could explain all this to the girl at the parts store, but she'd probably call the asylum.

White '67 LeMans 407/TH350/Ford 3.89... RIP
Red '67 LeMans. 407/TH400/Ford 3.25
  #7  
Old 01-23-2020, 02:17 PM
HWYSTR455's Avatar
HWYSTR455 HWYSTR455 is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Manassas, VA
Posts: 14,658
Default

Quote:
Originally Posted by steve25 View Post
With those 3.73 gears even though there a tad too stiff for a street 455 atleast you will be far less likely to have ping issues if your compression is a tad too high for that 068 Cam.
If your going over to 3.08 gears with more then a 9.2 compression then a bigger Cam will be needed.
Quote:
Originally Posted by chiphead View Post
….Use a cam with at least 230* intake duration and 112-114LSA.
Totally agree with both of those comments, they are right on target.

What are you having done with it at the machine shop? Are those parts you listed already up there ready to be installed by the machine shop?

If so, ask how far in the hole the pistons are, and what the CC of the chambers are, and state to hold on going forward until you have that info.

When you say 'retain stock valve hardware', do you mean you have bottle neck studs and OE type rocker nuts? If so, convert while they are doing the heads, to straight studs and poly locks, you will be much better off.

Also, are the stock valves being reused? I would highly recommend you replace with some stainless one piece valves, as well as springs to match whatever cam you plan to use. If you stay within a 'range' of cam profiles, the same springs/setup can be used across them.

The typical hyd cam failures have been fading lately, and I hear less and less of those 'old' issues. So wouldn't be too worried about that as long as you maintain proper assembly (gobs of lube) and break in procedures.

Generally, wider LSAs tend to ward off det, and 114 would be a good choice. There's a number of grinds that will get you there, if you want suggestions, you can reply asking, sure there will be a good selection of suggestions provided. If you want trouble free, then stay away for fast closing ramps.

.

__________________
.

1970 GTO Judge Tribute Pro-Tour Project 535 IA2
http://forums.maxperformanceinc.com/...d.php?t=760624
1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car
https://forums.maxperformanceinc.com...ght=procharger
Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be
  #8  
Old 01-23-2020, 02:18 PM
HWYSTR455's Avatar
HWYSTR455 HWYSTR455 is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Manassas, VA
Posts: 14,658
Default

If you plan on going to 308 gears, that will impact your cam selection, so chose a cam for the 308s, and not the current 373s.


.

__________________
.

1970 GTO Judge Tribute Pro-Tour Project 535 IA2
http://forums.maxperformanceinc.com/...d.php?t=760624
1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car
https://forums.maxperformanceinc.com...ght=procharger
Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be
  #9  
Old 01-23-2020, 02:45 PM
HWYSTR455's Avatar
HWYSTR455 HWYSTR455 is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Manassas, VA
Posts: 14,658
Default

I will probably get blazed for this, BUT, I personally have used this cam with 'highway' gears, with a 9.5 SCR 30 over 455, and had no issues. It was very easy to tune, and worked good across the entire RPM range. It gives up a little early for my liking, but if you're going for a cruiser, it would be perfect:

https://www.summitracing.com/parts/c...w/make/pontiac

If you want to step it up a little, you can go to a 112 LSA, and slightly more duration, like this one:

https://www.lunatipower.com/voodoo-h...8-276-284.html

You would have to call and have them cut it on a 112 LSA, would take about 2 weeks, but it's a very common request and is no extra cost.

Don't pay attention to the descriptions, they are very generalized. In a 455 with 9.5 it would be fine.

.

__________________
.

1970 GTO Judge Tribute Pro-Tour Project 535 IA2
http://forums.maxperformanceinc.com/...d.php?t=760624
1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car
https://forums.maxperformanceinc.com...ght=procharger
Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be
  #10  
Old 01-23-2020, 03:02 PM
track73 track73 is offline
Ultimate Warrior
 
Join Date: Nov 2006
Location: Munster In
Posts: 1,504
Default

In my humble opinion, if you are on a budget and are looking for the horse power you stated,you can't got wrong with the (041) RA4 cam. With better springs, Rhodes lifters and Big block Chevy screw in studs you would have a reasonable idle and lots of power without a lot of expense. But it's your car do what you want. Just be careful about who's giving you advice. Remember free advice is worth what you pay for it

__________________
1979 Trans Am WS-6 .030 455 zero decked
flat pistons
96 heads with SS valves
041 cam with Rhoads lifters 1.65 rockers
RPM rods
800 Cliffs Q Jet on Holley Street Dominator
ST-10 4 speed (3.42 first)
w 2.73 rear gear

__________________________________________________ _______________________________

469th TFS Korat Thailand 1968-69 F-4E Muzzle 2
  #11  
Old 01-23-2020, 03:06 PM
67gtospud's Avatar
67gtospud 67gtospud is offline
Ultimate Warrior
 
Join Date: Aug 2012
Location: Seymour, Wisconsin
Posts: 1,549
Default

Quote:
Originally Posted by HWYSTR455 View Post
I will probably get blazed for this, BUT, I personally have used this cam with 'highway' gears, with a 9.5 SCR 30 over 455, and had no issues. It was very easy to tune, and worked good across the entire RPM range. It gives up a little early for my liking, but if you're going for a cruiser, it would be perfect:

https://www.summitracing.com/parts/c...w/make/pontiac

If you want to step it up a little, you can go to a 112 LSA, and slightly more duration, like this one:

https://www.lunatipower.com/voodoo-h...8-276-284.html

You would have to call and have them cut it on a 112 LSA, would take about 2 weeks, but it's a very common request and is no extra cost.

Don't pay attention to the descriptions, they are very generalized. In a 455 with 9.5 it would be fine.

.


I second the 276/284 cam choice if you're on the fence. I ran this cam on the 110 lsa in my previous 400, with 3.36 gears, and it was a great street cam and pulled hard from idle right up to 6k. On a 112 lsa in a 455 would make for a great, streetable engine with either 3.73 or 3.08 gears.

__________________
1967 GTO, 432 (428+.030), 4-bolt mains, factory Nodular crank, scat rods, icon dished pistons, Lunati HR 243/251@.050, .618/.622 lift, Edelbrock 72cc round port heads, 10.5:1, offy 2-4 intake, Edelbrock 650cfm carbs, Super T10 trans (2.64 first), BOP 10 bolt w/ Eaton posi and 3.36 gears
  #12  
Old 01-23-2020, 08:07 PM
ponyakr's Avatar
ponyakr ponyakr is offline
Ultimate Warrior
 
Join Date: Dec 2011
Location: North Louisiana
Posts: 7,621
Default

Seems like every time a similar build comes up, I'm the only one who ever mentions this Howards cam. I don't know anybody who has ever tried one. So, I'm just going by the specs.

The reason I always mention it is because it has real close to the same @ .050 lift specs as the 041 clones, but has less adv duration, which means the idle & very low rpm manners should be better than the 041, IF using regular(not Rhoads) lifters, on both.

I ran the 041/Rhoads on most all my mild bracket 455's & loved 'em. But, as has been mentioned MANY times before, LOTS of guys can't live with the ticking sound of the Rhoads lifters. So, if you're one of those guys, but want a bit more cam than the Crane mentioned, then this 410051-14 Howards MAY be a good choice, to use without Rhoads lifters.

https://www.summitracing.com/parts/h...w/make/pontiac

This Crane is a little bigger than the one mentioned, and looks to be similar to that Howards cam.

https://www.summitracing.com/parts/c...w/make/pontiac

A higher priced cam, that fits somewhere between the small Crane mentioned & that Howards, is the Crower 60243. Don't know why Crower cams are so much higher than most others. Maybe they think their grinds or blanks are better, in some way or ways. I have no idea.

https://www.summitracing.com/parts/c...saAqlBEALw_wcB

The Summit 2802 is the cheapest decent 455 cam, IMO. Too small for most here. But should meet your hp goal of "...350-375 hp is fine...". It appears to be sort of a higher lift version of the current Melling SPC-3 cam.

https://www.summitracing.com/parts/s...RoCJdgQAvD_BwE

This one is in the same ball park as the 2802, but twice the price.

https://www.summitracing.com/parts/hrs-410141-12

If you wanna go a little smaller, but not all the way down to an 068 clone, or a Summit 2801, this Lunati might work. Should work great for under 5000 rpm operation.

https://www.summitracing.com/parts/lun-10510312/

Then there are some choices which are just a hair larger than the 041. For the power level you want, I don't think those are needed. And the fast ramp Voodoo cams seem like overkill for your power level, IMO.

Lots of choices.


Last edited by ponyakr; 01-23-2020 at 08:47 PM.
  #13  
Old 01-24-2020, 08:10 AM
79Poncho's Avatar
79Poncho 79Poncho is offline
Junior Member
 
Join Date: Mar 2006
Location: Brighton, MI
Posts: 11
Default

Quote:
Originally Posted by HWYSTR455 View Post

https://www.lunatipower.com/voodoo-h...8-276-284.html

You would have to call and have them cut it on a 112 LSA, would take about 2 weeks, but it's a very common request and is no extra cost.

Don't pay attention to the descriptions, they are very generalized. In a 455 with 9.5 it would be fine.

.
I don't want to hijack this thread, but since I'm building nearly the same setup, and am considering this Lunati Voodoo cam, would you recommend 1.65 rockers? I'm planning on re-using my Harland Sharps, but have concerns they may cause interference with this grind.

Thoughts?

Thanks, and sorry to the OP for jumping in here.

__________________
1979 Pontiac Trans Am
'75 Olds 350, Muncie M21, 3.23 Posi
  #14  
Old 01-24-2020, 08:31 AM
Cliff R's Avatar
Cliff R Cliff R is offline
Ultimate Warrior
 
Join Date: Nov 2000
Location: Mount Vernon, Ohio 43050
Posts: 17,972
Default

My first 455 was the same build, 6X-4 heads with minor clean-up (232cfm), TRW flat tops that came out at exactly zero deck w/o cutting the block, Crower rods, factory "N" crank, etc. I used Crowers version of the RAIV cam, part number 60919, high ratio rocker arms and Rhoads lifters. It idled with plenty of vacuum for power brakes, around 12" at 750rpms, strong power of idle, very efficient for normal driving, and cranked out 455.4 hp on the dyno. It was good enough for 12.0 second runs in the 1/4 mile at 112mph with 3.42 gears and DOT tires.

The final compression ratio calculated at 9.97 to 1 with a Felpro .039" head gasket. I had the heads cut slightly make sure they were flat and good sealing surface, they came in at 89cc. I put a LOT of street miles and drag strip runs on that engine and even used it for the KRE head testing and HPP and Popular Hot Rodding Engine Masters articles. It was fine on pump fuel, even 89 octane, and it never much cared or grumbled once on it.

I would NOT use less cam in it that 230 @ .050" for pump gas. Since I did that 455 we've done a number of others with iron heads around 10 to 1 compression and even did one with 1974 #46 350 heads that made 440hp on the dyno and we never did any porting of any kind on them.....Cliff

__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran!
https://cliffshighperformance.com/
73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile),
  #15  
Old 01-26-2020, 01:20 PM
HWYSTR455's Avatar
HWYSTR455 HWYSTR455 is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Manassas, VA
Posts: 14,658
Default

Quote:
Originally Posted by 79Poncho View Post
I don't want to hijack this thread, but since I'm building nearly the same setup, and am considering this Lunati Voodoo cam, would you recommend 1.65 rockers? I'm planning on re-using my Harland Sharps, but have concerns they may cause interference with this grind.

Thoughts?

Thanks, and sorry to the OP for jumping in here.
All I can say is you have to check. There's plenty of meat to clearance the HSs though, and a machine shop can back cut the area under the arm.

I used Crowers so there's no clearancing needed with those.


.

__________________
.

1970 GTO Judge Tribute Pro-Tour Project 535 IA2
http://forums.maxperformanceinc.com/...d.php?t=760624
1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car
https://forums.maxperformanceinc.com...ght=procharger
Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:30 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017