3.0 rebuild for performance advice

[groovydude]

I'm trying to figure out the best bang for buck in an engine performance upgrade/modification. The engine is a small port (1982) 3.0 with 120K miles. It had a top end and new rings at 95K, it has the original head studs I believe. Currently have stock CIS, SSI headers and Classic Retrofit CDI upgrade. I'll be doing my own work.

These seem to be my choices:

1. Don't open the engine, just add the following bolt on & tuning Cost ~ $500-$800. Expected gains = ???
- Set Cam timing to Euro
- Recurve the dizzy to Euro or replace with 123-ignition adjustable model.

2. Above PLUS new 10.5:1 CR pistons & cylinders. Clean up heads & keep single plug. Change head studs while I'm in there. Cost ~ $7200 Expected gains = ??? Also, do I need to replace the cylinders with these pistons, or can I run with the stock tubes?

3. Above plus more aggressive cam. Cost ~ $8200/ Expected gains = ???

It's the expected gains I'm trying to figure out of course. Any input will be appreciated. And if someone has thoughts for a different set of or additional mods, please speak up! Thanks.

[Glenfield]

Read through this: Best Cam Profile For A Stock SC?

You’ll see some interesting comparisons of torque and HP curves for small port v big port SCs. You’ll be surprised by the relative torque and HP of the small port 3.0 up to about 5500 RPM. Then it runs out of puff. Basically, it’s the intake port size that’s the limitation and more fuel won’t necessarily help you if engine can’t breath. So I wouldn’t do anything major without addressing that.

Also, don’t go to 10.5:1 without going dual-plug. If you’re changing P&Cs you’ll get more bang for your buck with displacement anyway. Both would obviously be ideal but then you’ll need to dual plug.

Also definitely worth checking out Al_Kosmal’s build threads here. Search his threads and look at the 3.0L builds. You’ll see some seriously impressive before and after shots and some dyno numbers of what a 3.2SS might spit out with and without EFI. The with EFI #s are impressive and not too late to ask Santa.

[icarp]

PM sent
Ian

[kent olsen]

When I built my 3.0L I built it to be bullit proof. I was doing a lot of track days and wanted something I could drive to the track, drive the daylights out of and drive home and only need to adjust the valves and change the oil once a year.

Consequently it had 9.5:1 pistons, twin plugs, webers and some racing tricks that would allow it to turn 8000rpm.

It did have the small valves but with the advise of my friend Jeff from Seattle we both went with a custom cam grind that lowered the torque peak (you need torque to pull out of the turns) but still developed peak horsepower at 6800rpm. Torque is 227@4800 and horsepower is 245@6800.

[AndrewCologne]

Originally Posted by groovydude

I'm trying to figure out the best bang for buck in an engine performance upgrade/modification. The engine is a small port (1982) 3.0 ... Currently have stock CIS, SSI headers and Classic Retrofit CDI upgrade. ....

What is your personal best bang for the bug? Street performance with having more torque at mid revs or .... more power obtaining at high revs? Thats what let get things/approaches here more specific.

These seem to be my choices:

1. Don't open the engine, just add the following bolt on & tuning Cost ~ $500-$800. Expected gains = ???
- Set Cam timing to Euro
- Recurve the dizzy to Euro or replace with 123-ignition adjustable model.

Setting cams to 0.9-1.1 will lower torque at mid revs and rise power at high revs.
As you already got a Retrofit CDI device I guess you also are aware that you can lock the distributor and set your own individual ignition curve easely via the software coming with the Retrofit product – so no Recurving of the dizzy oir even a purchase of a 123 ignition device is needed. The only plus of the 123 Ignition dizzi is in your specific case that it also supports a more aggresive vacuum advance cause of the ported vacuum support.

2. Above PLUS new 10.5:1 CR pistons & cylinders. Clean up heads & keep single plug. Change head studs while I'm in there. Cost ~ $7200 Expected gains = ??? Also, do I need to replace the cylinders with these pistons, or can I run with the stock tubes?

Whith a more agresssive ignition timing curve you will really beyond the limits with a CR of 10.5:1 as detonation is really risky here without knock sensoring.

3. Above plus more aggressive cam. Cost ~ $8200/ Expected gains = ???

Depends on the cams profile, but .... nearly all of them will force you to run the engine at high revs to really "noticably" feel the gain.

And here is where the small ports will be the bottle neck as at very high revs the airflow is limited compared to big port heads/manifolds


With all the money you're able to spend, I really would think of changing to EFI with a full engine management.
https://www.elferliste-service.de/index.php?/topic/8313-sc-mit-pmo-einzeldrossel-und-kms-efi/
(use an online translator) Unfortunately the pics aren't linked anymore.

For all other approaches like SSI, retading cam timing, 964 cams etc etc. See the end of my workshop in the link in my sig

[groovydude]

That's a great link, thanks! The car is for mostly street use. So midrange torque is probably what interests me most. I did not delve into the Retrofit CDI programming, but it looks like this is very much in order, thanks for the tip!

I'm getting a lot of input on an EFI conversion, which I had not thought of initially, but it looks like a good place to start. So, I'll change option #1 to EFI/ITB setup plus more aggressive timing. From what I can tell from my searches, I may be adding 30+ hp and lots of torque and throttle response with this mod, which seems to be worth the cost.

If 10.5:1 is too much compression, do you think there's enough gain to be had with a tamer P&C set up than what I mentioned, as in 9.8:1 (Euro)? It looks like in a stock car the Euro setup adds 20hp and proportional torque. I should add that cracking the engine open is not my first choice, but since I have original head studs there's some motivation to get in there and replace them. So changing the pistons makes some sense effort-wise if I'm going this route, but if it only adds 10hp I'm not sure it's worth the thousands in parts.

Can you tell me more about the vacuum advance advantages on the 123 dizzy? Just curious.

[AndrewCologne]

the 123 dizzy (the bluetooth one for 6pin CDI which you would need) comes with vacuum support, means with an integrated vacuum sensor and external vacuum hose connection where here the ported vacuum from the throttle body will be read and interpreted/ported to an extra ignition advance you individually can set up by software/app, like the mechanical advance.

[jehintheuk]

I have a US spec 82 Targa that started life in exactly the same place - US small port heads, etc. Though mine had nearly 200k miles on the engine when I bought it.
I started by reading the Bruce Anderson book from cover to cover, then doing what you are doing by talking to people on the forums.
I ended up getting carried away, but if you want a really nice road car, SSIs, euro Ps, 964 cams, the CDI+ ignition and better, more responsive induction (ITBs or Carbs) will transform the car. Open/flow the heads when they are off and it will be even better.

[KNIGHTRACE]

Put the M1 cam in it and the CIS will be happy with it.. KNIGHTRACE@MAC.COM

[icarp]

William , by M1 cam you mean the "Melissa cam" by web cam I. I spoke to Groovydude yesterday
He has lots to think about . I'll bet he'll choose the Melissa cam and high comp ratio pistons to go with CIS and probably include a WUR delete pressure regulator . this will bet the most cost effective. ian

[KNIGHTRACE]

You need to make the Warm Up kit for these people, The M1 is the Melissa cam. Melissa #1 is the code for M1

[Arlo911]

Ian, William, what is the Warm Up kit you guys mention?

[Kraftwerk]

More torque and 30 hp sounds like a nice thing, if it's not crazy money.
"Removing Weight" is always good to bring up, at some point, in these 'bang for the buck' discussions: zero cost.

[dml]

Originally Posted by arlo911

ian, william, what is the warm up kit you guys mention?

+1

[KNIGHTRACE]

Sorry for the delay, Ian is working on a car up north, he is making the system for the CIS cars, email me at knightrace@mac.com and I will forward it to him. It seems excellent in my opinion, you can adjust your A/F ratio from inside the car.. I have nothing to do with it as I am on the other side of the spectrum. But email me and I will forward it. Thanks, William

[trond]

my advice would be to not replace high quality nicasil Mahle cylinders with high risk aftermarket ones to get a bigger bore. With the small port heads stay with stock cams timed to 1.25 or so. With hotter cams you will be giving up low end torque while getting little or nothing back on top. 10.5CR is too much without twin spark. How about a set of Euro 9.8CR pistons from Mahle that does not require twin spark? Also; to run ignition advance from an ECU and lock distributor is not trivial wrt rotor phasing. The distributor rotor tip need to be aligned with terminal in distributor cap or there will be trouble. EFI does not add much if you already have a well functioning CIS except you will have a new hobby. I'd go with lightening car, 123 distributor, SSIs that you already have and a stock road muffler (not Sport) that will give slightly better torque below 4000 rpm. And do not open engine unless you know something is wrong. These engines age well

[KNIGHTRACE]

I agree with most of what Trond has written, however the M1 cam we developed on even an actual 8.2:1 compression 3 liter with small ports is gaining approximately 20 - 25 hp at the wheels. Ian has a set in his motor, we did not know the compression when he ordered the cams. I would have not expected that much of a gain on the lowest compression 3 liter with small ports. He has improved power across the entire RPM range. I personally prefer stroke over bore, many 3 liters here in the states haven't been rebuilt for 40 years and I feel it is a good idea to go through the motor in order not to see an expensive failure. There is a very high success rate even by non professionals. If your going to push the car on the weekends for spirited driving or DE or any aggressive driving there are some mandatory maintenance requirements and you can keep it pretty basic but most going to this level of work would like a little HP improvement.

[jac1976]

Originally Posted by KNIGHTRACE

I agree with most of what Trond has written, however the M1 cam we developed on even an actual 8.2:1 compression 3 liter with small ports is gaining approximately 20 - 25 hp at the wheels. Ian has a set in his motor, we did not know the compression when he ordered the cams. I would have not expected that much of a gain on the lowest compression 3 liter with small ports. He has improved power across the entire RPM range. I personally prefer stroke over bore, many 3 liters here in the states haven't been rebuilt for 40 years and I feel it is a good idea to go through the motor in order not to see an expensive failure. There is a very high success rate even by non professionals. If your going to push the car on the weekends for spirited driving or DE or any aggressive driving there are some mandatory maintenance requirements and you can keep it pretty basic but most going to this level of work would like a little HP improvement.

Any effect on low end torque?

[icarp]

A follow up with regards to what KNIGHTRACE said . William and I have been working an a CIS system for fun HP and TQ. The test mule is a 1980 sc small ports , SSI, Dansk sport hotdog, pistons are 9.3 comp ratio , Measured to 8.2/ 1 static comp ratio, . Ignition timing is 30* btdc @3000rpm. The valve seats are in good condition,
Hot leak down test @80 psi in.... 79.5 psi held very good ring seal all 6 cylinders .
Two years ago I did a fun run dyno and got 188 hp @ the crank . That is my benchmark. I installed the M1 web cam with new rocker faces , set the cam to web specs @ .050". The change in HP was good at the seat of the pants , but I knew it needed more fuel. Next comes the WUR delete , I chose to run a fuel injection regulator in the cockpit , between the seats , Scott G has one too ! . I also installed an AFR meter in the clock hole . Wow that woke the engine up. I run the AFR @ 13.4 most of the time , cruise on the tpk and it's 14.7 , nail it in the canyons and it's 12.9. Any control pressure I set , will yield the AFR I want . So now It's time for a real dyno run , Mustang Dyno Eddy Brake. I have asked KNIGHTRACE to post the dyno sheet . I am having trouble with posting pics . 186 hp at the wheels and 184 TQ ... to the crank that is 219 hp and 217 tq. I just drove the car 2,000 miles to the east coast . I managed 28 mpg @80mph. when I arrived we set off to the drag strip , Ceicel county MD.
Kermit did not disappoint me . Our rules were no hard starts , just traffic light starts , My friend was running his 2018 Civic Type R,,, best run of four , was a 14.2 @100.89.....I beat the civic R by .010 sec . Great fun I hope KNIGHTRACE can post the dyno sheet 150 tq at 2500rpm
max tq 184 @4900 and held 150 tq untill 6600. It is a very nice combo with lots of GO.
When I get home I will put in a set of 9.8 Mahle pistons and proper squish clearance . We will see what we make then ! For a small port engine on CSI, this is a ripping car, 0-60 5.6 sec's , no doubt about it .
I will be putting a kit together for this combo. As to the engine up grades , valve and guide work is important , So are studs, fasteners , and rocker faces , piston squish area clearance 1mm on the money , rocker shafts , all measurements , comp ratio measurement , oil pump and bearings ,I also am a bigger fan of stroke than bore , ask me about bore to stroke ratios , If you don't know the condition of the part then you don't know , find out and write it down , enough for now .
Ian

[KNIGHTRACE]

We have a dyno comparison but it made more power and torque at every RPM level. It is between 30-40 hp gain at the flywheel. It made more torque from 2500 rpm up. did not test much below 2500 RPM. Ian had all the dyno numbers and results. I will try to help him post them later. WK