Compression & Ignition Question

Your car is idling very nice with this C118 cam. But TA recommend a 3000-3500 Stall converter. I drive 99% on street, maybe once per year on a strip. Thats the reason why i would prefer a stall converter wich runs a bit higher than the stock.

C118 +6 adv. = to much powerloss an high stall

Custom cam: 228/235 probably on a 112 and ??? adv.?

Whats with this cam? TA_288-94H 504"- 230/ .504- 240 on a 114

Where i can find in desktop dyno2003 the DCR?

I dont like cam install on adv. because there is a huge powerloss...

 

Robert

What does the TA 212 show for HP using the Dyno2003?
And what does the TA C118 show for HP using the dyno2003?

 

With the TA212 439hp @ 5000 RPM with +5 advanced 397hp @ 5000 RPM
With the C118 435hp @ 5000 RPM with +5 advanced 398hp @ 5000 RPM

i guess there is anywhere a big fail in my dyno calculator o No:

 

yea.. but whats the torque numbers... torque is what makes stop light to stoplight street driving so much fun. if your not going to race it much i say shoot for the most torque not horsepower.. horsepower really affects the second half of the track and torque gets you moving. the more low end torque you have the lower stall you could use and be ok. just cause someone has a recommendation on a convertor dont mean you have to use that one to drive it.

 

Robert

The TA 212 should have shown a peak torque of just over 500 ft lbs at 3500 rpm and a peak horsepower of just over 400 at 4500 rpm.

The TA C118 should have shown a peak torque of around 500 ft lbs at 4300 rpm and a peak horsepower of around 450 at 5200 rpm.

These cams are ground on a 4 degree advanced lobe centerline and for street use. You want to use them at that timing location.
That is also what I based the above torque and horsepower specs on.

The bottom line is this: For a DCR of 8 with a SCR of 10.5 the intake valve cannot close on the seat (.006” lobe lift) before 70 degrees ABDC.

For a good idle and good low rpm fuel economy the valve overlap at .050 lobe lift should be close to 0 degrees or less especially if you
want the engine to sound stock for inspection.

The TA C118 has a wide LSA of 118 degrees giving an overlap of 0.5 degrees.

The TA C118 with the 4 degrees advance closes the intake valve at 72 degrees ABDC for a DCR of just under 7.9.

If you decide to use a different or custom cam, it needs to follow these guidelines.

Will you be using stock exhaust manifolds?

Paul

 

Have you fix your detonation problem with the new radatior and ta se heads? And what stall do you use?

regards

Robert

 

I would consider something like the 284-88H, it has quite a bit more advertised duration, which keeps the intake valve from closing so soon.

 

Robert

Does your L2353F pistons have valve reliefs?

Have you actually measured the volume in the dish?

Paul

 

Robert's last login was 3/29/11.
Ray

 

No they haven't a dish should they? . I my calculation i used 24cc for the piston and not the rated 27.8cc. I will measure out asap...


I guess the TA212 has a to high risk to produce detonation. And is only driveable with the right ignition timing and with some degrees advanced. Thats kills a lot of power and i guess i should take a another camshaft. Too bad that I have already bought...

The new fighters versus the killer high compression:

TA284-88H .475"-223'/.475"-230',110'
TA288-94H.504"-230'/.504"-240',114'
TAC118 .494"-228'/.491"-247',118'
Costum cam .493"-228 /.507"-235',110' I-cl 106 E-cl 114

A Question about the costum cam, is that possible that the intake/exhaust has a overlap from 11.5 degree? I mean, bigger overlap = badly idle?

Who should win?

Thanks

Robert

 

The second problem with the TA 212 is reaching your goal of 450 horsepower.
The TA 212 usually only makes around 400 horsepower.

Let’s look at the overlap @ .050 and the DCR based on a SCR of 10.5 for all 4 camshafts at a 4 degree advanced centerline.

TA 284-88H ___Overlap = 6.5 ___DCR = 8.15
TA 288-94H ___Overlap = 7.0 ___DCR = 7.7
TA C118 ______Overlap = 0.5 ___DCR = 7.9
Custom Cam __Overlap = 11.5___ DCR = with 228 duration is probably <8.0

The TA 284-88H DCR is a little high but could be adjusted to 8.0 by advancing it 2 degrees instead of 4. The duration is probably not long enough to reach the 450 hp goal.

For close to a stock idle, overlap needs to be near 0 degrees or less. The TA C118 is the only one that fits this criteria.

However the Custom Cam could be ground on a 116 LSA which would give it a 0 overlap.
We need the advertised duration for the Custom Cam.
I'm hoping the intake duration is close to 276.

The lifts shown above are based on a 1.6 rocker arm ratio. The stock rocker arm ratio is 1.55.
A 1.6 ratio rocker arm puts more force on the hydraulic lifter than the 1.55 and can keep the
lifter from staying pumped up at higher rpm. Use the 1.55 ratio valve lift specs instead.

The Data Sheets for the heads show there is no additional flow for lifts over .500

 

Round 2:

TA284-84 and TA212 failed...

Costum cam more information: 284/295 advertised duration. Paul wich spec would you change from the costum cam? I guess in my case is a costum cam the best solution?

C118 and TA288-94 are functional in my engine and they do the work, but it will get better...

Thanks all & paul for the help

regards

Robert

 

Yes. Also keep in mind you have a stock convertor. A bigger cam will not work as well with a stock convertor.

 

Since the SCR is 10.5 the intake valve must stay open till 70 degrees ABDC to have a DCR of 8 and anything past that point will help with detonation and allow the use of lower octane fuel.

For a near stock idle the valve overlap should not exceed 0 degrees.

To make around 450 hp or more with the TA heads and stock exhaust manifold, the intake duration needs to be around 228 degrees with the exhaust around 240 for the same lift.

The problem is you need a certain amount of duration to get the target horse power and a small overlap to have a near stock idle so as you spread the lobe separation to decrease the overlap, for a given duration the intake valve timing events are later causing a decrease in low end torque.
For street driving with a stock converter you might not care if you have to wait to get into the power band. On the track a higher stall converter is needed.

The Data Sheets for the heads show there is no additional flow for lifts over .500

The TA C118 at 4 degrees advanced closes the intake valve at 72 degrees ABDC.
It has an overlap of 0.5 degrees.
The exhaust duration is a little long but will work with stock unmodified exhaust manifolds.
The TA C118 still looks like a good choice.

If you change the LSA from 110 to 116 the overlap will be 0 degrees.

You can crunch numbers all day but there comes a point where it is time to talk to the people that know.

I will call TA Performance this week and get their advice.

Paul

 

I have this cam, and I use it with Gessler ported SE aluminum heads from TA Perf. The cam has a good lope to it but is not overly aggressive for the street. My car is mostly street driven but I do occasioally take it to the track. The heads and cam took my car from 12.20s to 11.80s. It's a good cam and will complement your heads nicely. John B.

 

Thanks Paul but you forget that i use TA2012 Fulllength Headers with a 2.5" X-Exhaust. Is now the C118 still the champ?
TA is very busy and it was very difficulty to get my last order. I cant phone, because my english not really good and from switzerland its very expensive...

If is necessary i would take a bigger stall converter 2000-2500... i think that give us more scope :TU:

Thanks a lot

Robert

 

Robert

I just talked to Tim at TA Performance.

I explained your engine combination with 10.5 static compression ratio.
Tim still recommended the TA 212 for the smooth idle and said with the aluminum heads and the 93 octane gas there shouldn't be any problem with detonation.
He stated that there are several cars running the same combination as yours with the TA 212 with 10.25 SCR.

Tim wanted to know which spark plugs you were going to use?

With the full headers you should be able to make 450 horsepower

The following links show a build using the TA 212 and a TA 413 with
Modified stock iron heads, Edelbrock and TA aluminum heads.

http://www.carcraft.com/techarticles/ccrp_0906_buick_455_engine_bolt_ons/index.html

http://www.carcraft.com/techarticles/ccrp_0907_buick_455_cylinder_heads/index.html

Since the L2353F piston doesn't offer much quench surface area I would do a .040 piston to deck height and keep a 10.1 SCR.

This will work well with the stock converter.

If you need 500 horsepower with stock idle, we talked about TA 288-96 profile ground on a 118 lobe separation angle.

Paul

 

I guess everybodies eyes glazed over when they read #35 because I said it would work fine. Not a big enough cam for some people.

The only thing I didn't mention was that the car ran 12.1's with that setup at 4250 lbs. I don't know what flywheel HP that was because I don't worry about HP claims, I only go by what it runs or actually measures.

If you're not going to race at the track then a tighter converter is no problem and will actually give you more top end speed. With a mild cam all a higher stall converter does is spin the tires even more when you have street tires on.

 

Mike

I went back and looked at #35 and I remember reading it. Because I came into this thread late, by the time I read the other 40 yours got mentally misplaced.
Then got sidetracked with number crunching.
The other part is trying to be conservative when recommending a combination so there is margin before a problem can occur.

Anyway it's interesting to see that after taking the long way around and talking to Tim at TA Performance, the conclusion ends up the same as in #35 including the same 2 links.

However the decision is Robert's.

I'm just here to put my 2 cents in and learn from the feedback.

Thanks for your reply. 12.1s are impressive!

Paul

 

I want a engine with a long life. I have enogh time to select the best cam for my setup and the TA212 is not the best. I know the TA212 has more torque in low rpm as many other cams. Thats good i like torque in low rpm ranges but the TA212 has a big handicap and thats is the DCR from 8.5 and a big pressure to crankshaft. Thats not really gentle for a long troublefree engine life. There are two ways to get the dcr down: more cam advanced or more deckheight. Both methods take power and torque.

I like the engine in the carcraft and i read this article several. They have a big quench around .081 with a 8.77:1 SCR no detonation or something else.
But what is with a 10.x SCR and with a huge quench from .080, volks says a good qunech is 0.04-0.05. I dont know the influence from the dished pistons about the qunech. Works a good quench with dished pistons? or is that only possible with flat, notched pistons?

I would like to use the E3 Sparks (Same as carcraft used)

Please unterstand me, i want a engine thats runs pulls and hears heathly. Its very expensive here and i have only one chance and that chance must work.

Mike thanks for sharing your experience, but u see self a TA212 with a 10.5:1 compression is not trouble free while driving. Check temp gauge manual shifts etc.....

Im very thanksful about every people who share me his experience..
And Pauls knowledge is very impressive like a rocket engineer :3gears:
And big thanks for asking Tim!

Thanks

Robert