Pontiac - Boost Turbo, supercharged, Nitrous, EFI & other Power Adders discussed here.

          
Reply
 
Thread Tools Display Modes
  #1  
Old 01-07-2020, 09:34 PM
AIR RAM AIR RAM is offline
Senior Chief
 
Join Date: Sep 2002
Location: Homestead FL
Posts: 412
Default Camshaft suggestions for a 496ci TT

As some may already know I am building a 496ci TT. Just got the flow numbers back from the head porter so I am starting to look for a SOLID ROLLER cam for it.

Build:
455 .040+
4.5 stroke
72cc EDL Round Ports Perf / RPM 2.19/1.77 (flow 332/242 @ .650)
1:5 HS rockers
CP 4.191 Pistons 40cc dish
MPFI Single Plane with 105mm throttle body
Leaning towards Dominator EFI ECU

TH400 w/ GV overdrive (Stall yet to be determined leaning 2600-2800)

Plan to run 8-10lbs for a set of twins and have mild street manors.

I'm thinking max lift should be around .650

SPEED SAFE, NICK
Attached Thumbnails
Click image for larger version

Name:	FLOW CHART PONTIAC EDL.jpg
Views:	441
Size:	41.6 KB
ID:	528399  

__________________
"The grass is not greener on the other side, its just fertilized with different $h!t"
  #2  
Old 01-10-2020, 09:31 AM
Jay S's Avatar
Jay S Jay S is offline
Ultimate Warrior
 
Join Date: May 2018
Location: Nebraska City, Nebraska
Posts: 1,671
Default

I am still studying and learning in the boost world, it seems like people are not as willing to dive into cams for boost. FWIW, we usually use Bullet for most of the cams we do for most of our tougher cam projects. I talk to Tim. I generally have a good idea of what I am doing before I talk to him. I have seen several guys on different Boards that run something from Bullet for boost. Tim is very helpful.

http://www.bulletcams.com/Masters/ultradynemasters.html

Just looking at your head flows and the cid with 10lbs of boost I would call Tim and start with the R43 and R16 lobes. 290/304 254/267 probably on a 116 lsa with a fair amount of advance, probably 6. Starting place anyway, that is as small as I would do. 1.6 rockers minus the lash would be in that .65.

The MSP profiles are in that .65 lift range, but I think they are a little to aggressive for much of a street effort. I have a hyd roller profile with solids lifters from Bullet the with 1.65 rockers it about .630 lift. .3823 lobe lift A Crower SS 1.7 rocker would get the lift close to .650. Lash for that is around .010 for running that particular grind as a hybrid. Putting many miles on something I prefer that route. Just some things to look at.


Last edited by Jay S; 01-10-2020 at 09:34 AM. Reason: Edit
  #3  
Old 01-10-2020, 11:03 AM
Jay S's Avatar
Jay S Jay S is offline
Ultimate Warrior
 
Join Date: May 2018
Location: Nebraska City, Nebraska
Posts: 1,671
Default

Sorry I missed the 1.5 HS rockers. Probably looking at a MSP from Bullet. Guys run those on the street, but you have to be on top of maintenance. Maybe a r125 and a r116, 255,267 @ .050.

I usually use .26 x 28” flow x 8 for hp targets on NA pump gas engines, I use 110% eff of wider lsa rollers. Guys get up to .27-.28 on pump gas. That .26 puts this at 690 hp @ 7000 in N\A. So 10lbs boost with average eff it is just over 1000 hp? Better intercooling 1100?? In a stock 455 block , 4.5 stroke with splayed mains? Man I thought I was crazy. Lol, You probably need the deep skirted girdle worse than any of my engines. Probably need one like my boosted 389 project. It is probably the only girdle I am working on that would maybe keep that 455 block from turning itself into 2 4 cylinders. I am working on that all day today, I am hoping to show Tom V. some of the models in the next couple weeks. Then likely everyone else the end of this month or in Feb. Good luck with your project..

  #4  
Old 01-11-2020, 10:10 AM
taff2's Avatar
taff2 taff2 is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: South Wales in UK.
Posts: 2,172
Default

I wouldn't use any thing over a 4.00" crank in a high power stock block combo,preferably a 3.75" crank. An extra pound or two of boost will more than make up for the (maybe) less low down torque, and will be much easier on the stock block. Side loading is dramatically increased with long strokes. Rod length and piston height (and piston speed) can be better manipulated with shorter stroke. JMO.
The trend in turbo solid roller cams these days seems to be shorter duration but with massive/aggressive lift, spring eaters for sure. Necessary for very high hp though I suppose.

  #5  
Old 01-11-2020, 11:03 AM
v869tr6's Avatar
v869tr6 v869tr6 is offline
Ultimate Warrior
 
Join Date: Sep 2003
Posts: 1,128
Default

How much power are you trying to make? Myself I would use a smaller cam and more boost to make the power I needed but I drive a lot of miles. My new cam is a Bullet brand solid roller with 250 duration @ 0.050" and 0.593" lift. and a 4 - 7 switch. I went with Bullet because they had a core that they could grind and not cut thru the case hardening again because I drive the car a lot.

  #6  
Old 01-11-2020, 08:52 PM
AIR RAM AIR RAM is offline
Senior Chief
 
Join Date: Sep 2002
Location: Homestead FL
Posts: 412
Default

I would fist like to thank all of your input. This is going to be a ton of fun and I look forward to the challenge of keeping it all together....LOL


Quote:
Originally Posted by Jay S View Post
Sorry I missed the 1.5 HS rockers. Probably looking at a MSP from Bullet. Guys run those on the street, but you have to be on top of maintenance. Maybe a r125 and a r116, 255,267 @ .050.

I usually use .26 x 28” flow x 8 for hp targets on NA pump gas engines, I use 110% eff of wider lsa rollers. Guys get up to .27-.28 on pump gas. That .26 puts this at 690 hp @ 7000 in N\A. So 10lbs boost with average eff it is just over 1000 hp? Better intercooling 1100?? In a stock 455 block , 4.5 stroke with splayed mains? Man I thought I was crazy. Lol, You probably need the deep skirted girdle worse than any of my engines. Probably need one like my boosted 389 project. It is probably the only girdle I am working on that would maybe keep that 455 block from turning itself into 2 4 cylinders. I am working on that all day today, I am hoping to show Tom V. some of the models in the next couple weeks. Then likely everyone else the end of this month or in Feb. Good luck with your project..
Although I would love an engine that can sing at 7000 RPMs this build will NOT... LOL. I am looking at 6000rpms tops and my starting target is going to be 5500.... and may inch up to 6000 from their depending on how much power its making and how everything looks/sounds... Yes the block does have all new program mains... 3 center splayed mains as well as front and rear mains. I really do wish a girdle was available... I really dont understand why they are not. Sure with deep pockets everyone can afford an aftermarket block, however reality is, not everyone can. And even with the work I have into my 455, the cost do not come no where close to the cost of an aftermarket block... so that debate is all BS. A girdle would be a fraction to make and sell yet add strength where the factory blocks are lacking and would open the door to the little guys and allow them to reliably make high HP (900-1000 possibly more) builds

I would like to hear more about your girdle,

Quote:
Originally Posted by taff2 View Post
I wouldn't use any thing over a 4.00" crank in a high power stock block combo,preferably a 3.75" crank. An extra pound or two of boost will more than make up for the (maybe) less low down torque, and will be much easier on the stock block. Side loading is dramatically increased with long strokes. Rod length and piston height (and piston speed) can be better manipulated with shorter stroke. JMO.
The trend in turbo solid roller cams these days seems to be shorter duration but with massive/aggressive lift, spring eaters for sure. Necessary for very high hp though I suppose.
Yeah, this build was more of a long time plan that I made nearly 15 years ago. I purchased the 455 block with the intention of building a 500ci Pontiac on 15lbs of boost. As I have gotten closer to building it, the reality of the blocks being a limiting factor has convinced me that 15lbs was way to much boost... and 10lbs is also looking to be on the high side... LOL.

However, this is not a drag car and was never intended to be one. I am looking for a super docile idle with a fully muffled exhaust and artic cold AC. I dont want the sound of the car to give away whats under the hood... So the car will look like a well built show car on the street and unsuspecting will not expect the monster under the hood sitting next to them. I also intend to have a cooling system that is more than prepared to keep it all cool sitting in Miami traffic during rush hour.

The goal is to have a cam that makes for a very mild "Prius" like idle NA and then add 8-10lbs of boost on top of that. I was planning on keeping RPMS down below 6000 range.... We will see how things go as we add and turn the boost up.

Quote:
Originally Posted by v869tr6 View Post
How much power are you trying to make? Myself I would use a smaller cam and more boost to make the power I needed but I drive a lot of miles. My new cam is a Bullet brand solid roller with 250 duration @ 0.050" and 0.593" lift. and a 4 - 7 switch. I went with Bullet because they had a core that they could grind and not cut thru the case hardening again because I drive the car a lot.
I honestly do NOT have a HP goal... I will be happy NOT to make more than 850hp LOL The intention is NOT to go for an ALL OUT effort build... I do plan on the 4-7 swap on the cam and ignition. It will be a Multi Port FI ECM car and running both a motor plate and mid plate to help keep twisting forces at bay... I may even add a solid center mount for even greater bracing to keep twisting forces down and brace the block between the frame.

The rotating assembly is nearly zero balanced and it will also be running an ATI superdamper... I also dont plan to introduce the boost for about a year after its been built and running on the street. I want to first run it NA so I can break it in without worry of blowing it up, validate the cooling sys and tune. Once everything is running reliably and ability to cool is validated I will start it on 5lbs of boost and work my way up to 10lbs from there...

So the cam I go with would really need to be a mild cam...

Thanks again for all the input!!

SPEED SAFE, NICK

__________________
"The grass is not greener on the other side, its just fertilized with different $h!t"

Last edited by AIR RAM; 01-11-2020 at 09:09 PM.
  #7  
Old 01-11-2020, 11:39 PM
v869tr6's Avatar
v869tr6 v869tr6 is offline
Ultimate Warrior
 
Join Date: Sep 2003
Posts: 1,128
Default

My factory 400 block is filled to the bottom of the water pump holes and a Pro Gram eng. caps on the center 3 mains. 4.5" stroke and the short block has been together for 10 years with it a 20 psi most of the time on the dragstrip, 16 to 18 on the street. The cam is a flat tappet hyd. with 0.488 lift and 224/232 duration @ 0.050" and it only really make power to about 5600 rpm with the boost at 20 psi.
At 20 psi it makes about 800 at the tire at 5300 rpm and well into the 900 range on torque. Good luck on your project, you will love boost. Turbo Pontiac's to the front.
And I should mention my old 455 2bolt short block that still has factory bolts, with worked cast rods, cast factory crank and a set of Ross pistons went 6.02 at 120mph to the 1/8 mile, with a bunch of boost.


Last edited by v869tr6; 01-11-2020 at 11:45 PM.
  #8  
Old 01-12-2020, 08:42 PM
Jay S's Avatar
Jay S Jay S is offline
Ultimate Warrior
 
Join Date: May 2018
Location: Nebraska City, Nebraska
Posts: 1,671
Default

Sorry I must have plugged in a number wrong. Max power on a N/A engine with a 110% eff at .26 hp x cfm x 8 is 690 hp @ 6343 rpm. Not sure how I cam up with 7k. Then I come up with just over 1000 hp with 10 lbs of boost.

With heads flowing 330 + and the big cid and stroke you probably do not need a lot of cam or a lot of boost for the street.

The boost engines I have done were 318 LA Mopars with 214/224 cams, .443/.465. We did boost from single digits up into the lower 20s. Small cam but comparatively slightly bigger than a 224/232 would be in a 4.5 stroke Pontiac. We started with a stock head, and moved to ported heads eventually. We played with different turbos and A/R ratios. N/A the engine made max power with that little cam at around 5200-5500. There was a couple turbo variations we tried that peak power moved to 6000. We did some experimenting without the waste gate with some high octane fuel and the power band was very flat, and didn’t fall of until some place past 7500 rpm. I don’t see any issue making the big cubes and small cam work. It appears to me you could get by with a lot less lift than .65 on boost if your serious about putting miles on your car. Maybe could do a programable waste gate with a smallish cam and make the turbo work harder at the top end, that might be the best of both worlds.


Last edited by Jay S; 01-12-2020 at 08:44 PM. Reason: Edit
  #9  
Old 01-12-2020, 09:13 PM
AIR RAM AIR RAM is offline
Senior Chief
 
Join Date: Sep 2002
Location: Homestead FL
Posts: 412
Default

Quote:
Originally Posted by v869tr6 View Post
My factory 400 block is filled to the bottom of the water pump holes and a Pro Gram eng. caps on the center 3 mains. 4.5" stroke and the short block has been together for 10 years with it a 20 psi most of the time on the dragstrip, 16 to 18 on the street. The cam is a flat tappet hyd. with 0.488 lift and 224/232 duration @ 0.050" and it only really make power to about 5600 rpm with the boost at 20 psi.
At 20 psi it makes about 800 at the tire at 5300 rpm and well into the 900 range on torque. Good luck on your project, you will love boost. Turbo Pontiac's to the front.

And I should mention my old 455 2bolt short block that still has factory bolts, with worked cast rods, cast factory crank and a set of Ross pistons went 6.02 at 120mph to the 1/8 mile, with a bunch of boost.
Your build sounds like a ton of fun! I have my fingers crossed that mine has a similar long geverty... I am doing everything I can to address all known areas to be improved on to help the block survive. The rotating assembly while may not be the lightest... its lighter than the factory rotating assembly... and its also nearly zero balanced... (.03 OzInch) I hope that teamed up with the ATI super damper will remove harmonic factors from the equation... Plus the ECM tuning should help insure the tune is not silently beating the engine up from the inside out. So those are some contributors I believe where a huge factor in the demise of many blocks where HP alone was blamed.

It sounds like your engines are well sorted out, thank you for your input!!!

SPEED SAFE, NICK

__________________
"The grass is not greener on the other side, its just fertilized with different $h!t"
  #10  
Old 01-12-2020, 09:27 PM
AIR RAM AIR RAM is offline
Senior Chief
 
Join Date: Sep 2002
Location: Homestead FL
Posts: 412
Default

Quote:
Originally Posted by Jay S View Post
Sorry I must have plugged in a number wrong. Max power on a N/A engine with a 110% eff at .26 hp x cfm x 8 is 690 hp @ 6343 rpm. Not sure how I cam up with 7k. Then I come up with just over 1000 hp with 10 lbs of boost.

With heads flowing 330 + and the big cid and stroke you probably do not need a lot of cam or a lot of boost for the street.

The boost engines I have done were 318 LA Mopars with 214/224 cams, .443/.465. We did boost from single digits up into the lower 20s. Small cam but comparatively slightly bigger than a 224/232 would be in a 4.5 stroke Pontiac. We started with a stock head, and moved to ported heads eventually. We played with different turbos and A/R ratios. N/A the engine made max power with that little cam at around 5200-5500. There was a couple turbo variations we tried that peak power moved to 6000. We did some experimenting without the waste gate with some high octane fuel and the power band was very flat, and didn’t fall of until some place past 7500 rpm. I don’t see any issue making the big cubes and small cam work. It appears to me you could get by with a lot less lift than .65 on boost if your serious about putting miles on your car. Maybe could do a programmable waste gate with a smallish cam and make the turbo work harder at the top end, that might be the best of both worlds.
We are definitely on the same page now. I may chose a cam with even less lift just so I can take advantage of a bit more boost... I was leaning on 650 only because its right in the sweet spot of the head flow. I am leaning on a solid roller however that could flip to Hydraulic... everything is still under consideration.

I do plan on using the ECM to progressively control the boost controller. The objective is for the boost to come on progressively yet consistently and most importantly predictably. I am not sure how much control I can have over the boost controller yet however I do plan to use the ECM to control boost as a large part of tuning. I would love to make it feel seemless with NA like predictability into the throttle positions. I would love to road course it out here at Miami International Speedway periodically for fun, However I feel turbos can be unpredictable exiting the corners while easing on the throttle... But If I can control them with the ECM and make them predictable that would be AWESOME!

SPEED SAFE, NICK

__________________
"The grass is not greener on the other side, its just fertilized with different $h!t"
  #11  
Old 05-29-2020, 07:32 AM
AIR RAM AIR RAM is offline
Senior Chief
 
Join Date: Sep 2002
Location: Homestead FL
Posts: 412
Default

I decided to bring up my older post instead of starting a new one,

I ordered an MR1 block and camshaft from a well known (we all know them) reputable shop and leaned on them for a camshaft recommendation. However the person recommending the camshaft either can not or will not give any details as to how this cam will perform with my combination. He is just saying he chose it based on my combination and needs. I really dont like the idea of paying for an "unknown" and would think that if a person knows how to select a cam, they would be able to give details as to what the effective RPM range would be both NA and when under boost with an approximate HP/TQ target... unfortunately this person just will not give any details... its a bit concerning to me and I am not comfortable purchasing question marks.

The only thing on my combination that is changing from above it that i will be using an MR1 block.

So here is the only information he was willing to share and I am expected to trust its what I asked for.

"Nick,
Ok, I would go with a cam like a 238/238 with app. .600 lift and 115 l/s. "

That's it... hell this may be the best cam ever however I dont have much to go on. So the question is, does anyone have any idea as to what could be expected with this grind?



Thanks ahead of time.

SPEED SAFE, NICK

__________________
"The grass is not greener on the other side, its just fertilized with different $h!t"
  #12  
Old 05-29-2020, 12:45 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,294
Default

A 238/238 duration @ .050 camshaft with .600 lift would not be my first choice on a 496 cid engine.

That is all I am going to say on this topic.

Tom V.

__________________
"Engineers do stuff for reasons" Tom Vaught

Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward.
  #13  
Old 05-29-2020, 04:53 PM
charlie66's Avatar
charlie66 charlie66 is offline
Ultimate Warrior
 
Join Date: Dec 2004
Posts: 3,261
Default

Call Tim at Bullet . He will set you up for what you need...

__________________
My Half AN Injun.....
  #14  
Old 05-29-2020, 05:13 PM
TransAm 474's Avatar
TransAm 474 TransAm 474 is offline
Chief Ponti-yacker
 
Join Date: Jun 2004
Location: Cape Fair,Mo
Posts: 792
Default

I worked with Mark at Bullet for my custom Solid Flat Tappet going in my 461 with a single SXE480 turbo. Really great guy to work with, very knowledgeable person.

Just a side note... Mine is bigger than 238/238, and I only have a 461.

__________________
1978 Trans Am
Pump Gas 461 Stroker

Last edited by TransAm 474; 05-29-2020 at 05:24 PM.
  #15  
Old 05-29-2020, 06:09 PM
taff2's Avatar
taff2 taff2 is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: South Wales in UK.
Posts: 2,172
Default

My custom solid flat tappet from Comp was 250/248 @.050" and .600" lift on a 421 combo, and it drove like a stocker.

The Following User Says Thank You to taff2 For This Useful Post:
  #16  
Old 05-29-2020, 06:40 PM
TransAm 474's Avatar
TransAm 474 TransAm 474 is offline
Chief Ponti-yacker
 
Join Date: Jun 2004
Location: Cape Fair,Mo
Posts: 792
Default

Quote:
Originally Posted by taff2 View Post
My custom solid flat tappet from Comp was 250/248 @.050" and .600" lift on a 421 combo, and it drove like a stocker.
Taff, yours is fairly close to mine. Mark spec'd mine at 252/256 @.050" and .596"/.607" lift with 1.65 rocker, 114° Lobe Separation. It uses UF282 Master Intake Lobe and UF286 Master Exhaust Lobe. This is for my street 461. He said to install it at 110° Intake Centerline.

__________________
1978 Trans Am
Pump Gas 461 Stroker
  #17  
Old 05-29-2020, 08:05 PM
charlie66's Avatar
charlie66 charlie66 is offline
Ultimate Warrior
 
Join Date: Dec 2004
Posts: 3,261
Default

Quote:
Originally Posted by AIR RAM View Post
I decided to bring up my older post instead of starting a new one,

I ordered an MR1 block and camshaft from a well known (we all know them) reputable shop and leaned on them for a camshaft recommendation. However the person recommending the camshaft either can not or will not give any details as to how this cam will perform with my combination. He is just saying he chose it based on my combination and needs. I really dont like the idea of paying for an "unknown" and would think that if a person knows how to select a cam, they would be able to give details as to what the effective RPM range would be both NA and when under boost with an approximate HP/TQ target... unfortunately this person just will not give any details... its a bit concerning to me and I am not comfortable purchasing question marks.

The only thing on my combination that is changing from above it that i will be using an MR1 block.

So here is the only information he was willing to share and I am expected to trust its what I asked for.

"Nick,
Ok, I would go with a cam like a 238/238 with app. .600 lift and 115 l/s. "

That's it... hell this may be the best cam ever however I dont have much to go on. So the question is, does anyone have any idea as to what could be expected with this grind?



Thanks ahead of time.

SPEED SAFE, NICK
I think that you will be fine if all the opening and closing points are right.

I have a 325 cfm e-head and i use to run a .050 @.242/252 .550/.580 . Then changed to a .232/.242 with everything else the same. It still made the power but at 600 rpms lower. The way i see it is as long as your valves are big enough you're good to go . A little extra psi is all you will need.. JMO

__________________
My Half AN Injun.....
  #18  
Old 05-29-2020, 09:13 PM
Scott65's Avatar
Scott65 Scott65 is offline
Ultimate Warrior
 
Join Date: Jan 2002
Location: Houston, Texas
Posts: 1,991
Default

A cam with a cam card with all the timing events isn't too much to ask for. Will come in handy when trying to time injection events. Especially with boost

__________________
'65 Tempest 467 3650# 11.30@120.31
  #19  
Old 05-29-2020, 11:34 PM
Lee's Avatar
Lee Lee is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Crosby, TX (East of Houston)/Texas/USA
Posts: 2,054
Default

I'll play :-) I had a guy get a turbo cam from Bullet (most likely Tim). Then I designed a different one for him with less intake duration but a BUNCH more exhaust - also ground by Bullet. Mine put 80+ more hp to the wheels. This was an LS.

IMHO, turbo motors like for the exhaust valve to open MUCH earlier than what most suspect. The LS turbo cams I've had ground have all had at least a 30 degree larger exhaust lobe, some even larger. Most of that is towards the opening.

A recent LS HR Turbo cam I had Comp grind. Engine won't be on the road for a couple months, though.


__________________
'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'.

'67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust

My webpage http://lnlpd.com/home

Last edited by Lee; 05-29-2020 at 11:39 PM.
  #20  
Old 05-30-2020, 07:44 AM
taff2's Avatar
taff2 taff2 is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: South Wales in UK.
Posts: 2,172
Default

My current solid roller is in that direction, 260 I /270 E @.050" ,lowish lift at .685" with 1.65 rocker arms, much more lift and I find that they start to eat valve springs.

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 07:55 AM.

 

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