Good morning Gents...I'm looking for some advice from the hardcore engine guru's....Here's my situation, last year, I completely overhauled my 66 coupe, bone stock 289v2 sitting infront of a stock C4 and 8in 3.20 rear end, and made the following modifications:

1) Block gutted, tanked, fluxed and new freeze plugs
2) Cylinders .030 over
2) Crank turned .020
3) New SpeedPro Hyper (H273CP) pistons
-New ARP 3/8 bolts
4) New Edlebrock Performer Plus Cam (2122)
5) New Edelbrock Perform Intake (2121)
6) New Edelbrock 600cfm Auto Carb (1406)
7) New Edelbrock double roller timing chain
8) Stock heads rebuilt with recommended springs and valve job
9) Pertronix Flamethrower HEI distributor
10) Shelby Tri-Y headers
11) Full 2.5" Flowmaster 40 with H pipe

So as you can see, I've tried to cover everything and though in hindsight, I should have gone Crate but the wife had an influence...

My ask here is complex and beyond my technical capabilities. Though I've seen an improvement in performance, I need more. I want to up the HP with a bigger cam and new alum heads but I'm told my piston selection my limit my options as the CR rating for the H273CP's is around 8:5ish with a 63cc chamber. I really don't want to replace the pistons again but I want better flow and significantly more aggressive and better sounding cam (thinking Comp Cams ***** Thumper)

Anyway, I'd like some advise on what options I have to get a more a aggressive 289 with put better heads, bigger cam and likely a new intake on, given the Compression Ratio which I "think" is far less than 9:1 and the larger Combustion Chamber on the 289…

What's the worst that would happen if I threw an RPM Performer package or the equiv. on there? Would would I see in power output?

No blower recommendations please, but would entertain any feedback and advise…

 

Hiya,

not an engine builder !!!!! but what's holding you back is this:
4) New Edlebrock Performer Plus Cam (2122)
5) New Edelbrock Perform Intake (2121)
8) Stock heads rebuilt with recommended springs and valve job

i pulled the specs if anyone else joins in for the 2122 cam:
===========================
Duration at 0.006" Lift: Intake: 270° Exhaust: 280°
Duration at 0.050" Lift: Intake: 204° Exhaust: 214°
Lift at Cam: Intake: 0.280" Exhaust: 0.295"
Lift at Valve: Intake: 0.448" Exhaust: 0.472"
Timing at 0.050" lift: Open Close
Intake: 5° ATDC 29° ABDC
Exhaust: 44° BBDC 10° BTDC
Centerlines: Lobe Separation - 112° Intake Centerline - 107°
===========================

With a different cam you should get diffrent results already.
nice and streetable would be comp cams xe256 or similar i would guess anything more agreesive will not see any help with the stock heads.

If you're interested in getting heads, I'm currently running the edelbrock rpm top end on my 302. It's advertised 350HP on flywheel and i have serious doubts it's anywhere near that. I might just scratch the 300 mark.

I bought the engine as is, but if I had to buy a set of heads I'd probably go for the trick flow twisted wedge, or if you need cheap get a cast iron GT40 head (not gt40p). I hear from a different post there should be plenty of them now on the scrapyards. That'll increase power since the stock 289 heads are shockingly poor performers ....

the 8.5ish CR is obviously something that's holding you back and I believe (google) the GT40s are 64.5cc

AFRs non-emission 165cc heads are 58cc chamber volume, that with a matching cam should make your car fly ...

at least that's my opinion ... let's see what the people have to say that actually know what they're talking about

Kalli




Kalli

 

We need to know two things about your pistons to confirm the compression ratio question. We need to know how far in the hole they are at TDC and how much dish or valve relief in CCs they have. Never believe the CR the piston manufacturers advertise because they are always wrong unless you have the exact same setup as they used in testing. We also need to know what the rest of the rotating assembly is so we can see if it will hold up to your goals.

What type of fuel you want to use will dictate what CR you should shoot for. What do you want to run (i.e. 87, 91, 93, 108, alcohol, etc)?

The next thing we need to know is what are your goals? Do you want low end power, high end power, a rowdy idle, smooth cruise, etc. What do you want? There are always trade offs, but until we know what you want, it is hard to discuss what trade offs and help you make decisions.

 

You might get some ideas by downloading CamQuest from compcams website. You can plug in different variables, intake, headers, heads, CR, etc. and see what it does to the cam selection for what your goals are as asked in the previous thread.
Jon

 

Hey guys, many thanks for the quick replies...To Urban Cowboy, I have no idea how deep the piston is at TDC nor the valve relief CC's...All I want out of this car is to get that seat of your pants feel (350HP should do it) that gives off a "rowdy" rumble and leaves no room for interpretation...She's not a daily driver, won't go long distances and will never see rain or snow...I'd be satisfied with Premium pump gas but not disappointed with lower octane either...I do plan upgrade the rearend to 3.55+ but thats after I get the motor where I want it...

To Kalli, as usual I appreciate your feedback as well...Your spot on in that the Performer equip has to go...The term "Stock Improvement" says it all...With respect to the heads, I'd prefer to go big or go home, so though I can get my hands on some GT40's, I'm leaning toward the AFR's, lumpy Cam (500+ lift), another intake and maybe a Holley Avenger...

Do you think that will get me to my goal?

 

a 289 with proper heads(valvetrain)/cam/intake/carb combination will produce 350Hp flywheel assuming the bottom end can take it and spin to 6500. for that your goal is not unrealistic. assuming you really run 8.3CR at the moment with 63cc heads, I'd assume the 58cc heads will bump it up to just under 9 and with lumpy cam should be no problem with premium fuel whatsoever.
this 350Hp only when you have everything right. my engine should have that and i'm still chasing 50+ horses (timing etc or whatever i'm doing wrong)
so yes. if the bottom end can take it and you have no valve clearance issues, with those AFR165cc matching cam, intake and carb I don't see a problem

what carb dop you have, maybe no need to change that

[note:valve overlap makes lumpy, not high lift]

 

Hey Kalli, really appreciate your continued feedback...Also thanks for the little "note" as well. Sort of defines my automotive background...With respect to my carb, I've got the Edelbrock 600cfm auto choke (pn1406)...I mistakenly bought this and thought I could tune it out of its "economy" state...I've been somewhat successful, but know this is not the right carb...

What would you need to know about the bottom end, to know whether she's capable of spinning up to 6500? Stock crank .20 under, stock rods with upgraded ARP bolts and Speedpro Hyper Pistons...

Thanks again!

 

arp bolts at the conrod bolts is a very important place to start. they seem to brake at 5500 when stock (at least I hear so).
as for the carb, leave it. don't upgrade. it might be just perfect for this application (not joking!). In any case I'd use it and try to tune it before I'd spend money on a different 600cfm carb ...
as for the heads, look into trick flow twisted wedge heads as well. i only hear good about them (here on the forums):
https://mustangforums.com/forum/clas...-upgrades.html


I've had a look at the thumper cams and although they sound great I don't have any dyno graphs compared to the XE cams. From readin the specs I would have assumed they only make power at the very very top and you'd loose a lot of torque at bottom end. If it would be my choice I would probably shove in a 31-242-3 cam (XE268). but someone with Thumpr experience or maybe even compcams can assist you on that.
In any case I cannot see a reason on why you couldn't run a AFR165 or TFS with the 2.02 valves (see the recent post asking about head recommendation). they shouldn't interfer. that coupled with a nice dual plane intake and similar cam to quoted should be bang on 350 flywheel

but as said I'm not an engine builder, I'd prefer if someone else joins in.
Or if you made up your mind check with the manufacturers on recommendations.

best regards,

Kalli

 

If you plan to keep the stock heads, they'll continue to kill your performance until you (at least) port-match the exhaust. 289/302 heads were horrible in this regard, but some simple matching can give you an improvement that will feel like you put in a better cam.

You don't have to go far into the port, usually not a half inch in from the gasket.

 

that's one very good description on how and why to port the stock 289 heads. if you have to keep those cast iron door stoppers then that's what one would do