What I got...

91 Formula
305 TPI
5 Speed A5 (in a couple weeks!)
Jet Hot Hooker 2055's, 3" exhaust
3.42 Rear end Gears
EBL P4 Flash (for tuning)

Parts I have...
Ported Plenum (installed)
AS&M Large Tube runners (Not)
TPI Edelbrock High Flow base (Not)
Trick Flow 175 23 with .600 lift - more info below
http://www.summitracing.com/parts/tf...0007/overview/

Plenum already ported to runners...
I would port the base to runners and base to heads (if needed)

What cam do you suggest?
It's a street car, so I would rather lean towards the side of good idle manners, etc...
Also, Roller rockers, 1.5 or 1.6?
I'll probably need more than 19lb. injectors too...

I did a search, and I see many threads talking about these heads, but not many using them in 305 TPI (or at least posted, saw some with 350 or 355's that had them)

Thanks in advance!

Rafael

 

Stock Cam (same as 350 for that year, specs found on www.thirdgen.org)

GM Stock Cams
Model Number .05" Duration 1.5:1 Lift 1.6:1 Lift Lobe Sep. Notes
10111773 202/207 .413/.428 .441/.457 114.5 90-92 350,305

 

Found this... Specifically designed for TPI and based on the others, it emphasizes "super low end and mid range" power, which of course is already the benefits of TPI, I don't think I want a cam that's gonna fight that trying to get more top end power...

http://www.compcams.com/Company/CC/c...?csid=207&sb=0

Part # 08-465-8

Lift is just below .6, (I'm assuming that is with 1.5 rockers), so heads with 1.5 should be good...

??

 

Thats a cam i would try. Lift is with 1.6 so run a 1.5 or 1.6 with your heads.

If you had a stealth ram or wanted more lope and top end, try the next xfi size up the 268

 

From CompCams:
"That cam has high lift and very aggressive lobe profiles so it may change the behavior of the engine enough to require a stock computer to be modified. That cam has a pretty smooth idle...it may have a little rumble to it, but nothing choppy, or any lope to it. "

 

Yes with heads intake and any cam you will want to modify tune

 

the TPI setup is going to choke out those heads pretty badly. i'm in the process as you except i'm going to use an HSR and am leaning toward a CC503 cam.

 

I dropped CompCams a note and seeing which they recommend between the 260 and 268 XFI... I saw a lot of threads about the 268, but not much about the 260... The 268 had a bit higher lift and moves the power band up the RPM range a bit more than the 260

Should I have any concern about (over) porting the Edelbrock TPI base (with the Trick Flow 175) the Comp Cam on a 305 (Ported Plenum / AS&M Runners) ???

I've seen where the heads can flow 242 CFM and the base can be ported to flow 260...

 

CompCams (concerning the 260 or 268 XFI)

"That 260XFI in your 305 will perform like that 268XFI in a 350."

 

Not really true by any means.

 

I agree.. an explanation would of been nice...

 

I think comp ment rpm range and idle quality would be comparative

 

I asked for an explanation....

"The same cam in a smaller engine will "feel" bigger than it would in a larger engine with the same compression."

Which I could then ask, what is "feels bigger", more lift, longer duration, etc...

 

Feels bigger as in more overlap making rougher idle more lope and a higher trq curve so when cam comes into power it comes in harder because its lazy down low amd turns on a switch in the mid upper rpms.

It takes like 5-8 deg more duration for every 30 or so cubic inches to maintain similar power curve shape.
305 may peak power at 5500 rpm with 210 deg cam
350 may peak power at 5500 with a 218 deg cam
383 may peak power at 5500 with a 224-226 deg cam

Rough guidelines.

Power wont be the same at all if heads feed all motors but the shape of curve will look similar

 

Thanks Orr89RocZ,
Still leaning towards the 260, from the tons of things I've read, seems that anyone doing head and or cam swap on tpi ends up gaining some on the high end anyway...

Rafael

 

I did some research and found that the Edelbrock Base out and Trick Flow 175 heads in, are already matched, 1.230 in. x 1.990 in.

Next size up is 1.280 in. x 2.090...
A 0.05 and 0.1 difference...

Should I port them to the bigger size, or leave them as is...
I know smaller promotes torque and bigger higher RPM, so I'm leaning towards leaving them as is...

I will send the base to get ported / matched to the AS&M runners.

I also found some 1.65 rockers that will give a lift of .57, still under .6...

 

Leave as is. Match runners to base but taper in as much as possible

 

Thoughts on the 1.65 rockers?

I've done tons of searches...
I see many people asking about best 305 heads, but no further posts...
I see a few people have them, but non TPI, and some on 350's...

Anyone with these heads on 305 TPI?

Next issues will be injector sizing....

Rafael

 

Good heads for a 305. 1.6 vs 1.65 not much a difference. Can has plenty of lift for a 305 as is. I'd get whatever you can for the best price with rockers. Setting them up with right geometry is most important

30 lbs will cover everything that car will see.
24 lbs likely should as well.

 

From Cam Quest...

This might be fun in a 5 speed ?!?!?

Not taking into account ported plenum, AS&M Runners or ported Edelbrock base or 1.65 full rockers...

 

Sounds somewhat accurate. Heads plus intake should see well over 300 crank

 

Heads arrive tomorrow...
Astro A5 getting picked up next Friday (hopefully)
Then save for all the other stuff (cam, lifters, rockers, injectors, etc...)
I'll send the base out to get ported....

 

Dyno2000...

Curves are flatter, but total numbers are close...
Peak HP 307 @ 5000 rpm, Peak TQ 377 @ 3500 rpm (Flywheel)
Again, can not compensate for ported intake items, etc...

Both graphs are with the XFI 260 cam.

 

I built a 305 on camquest with the tf2 heads, cc503 cam and std flow tunnel ram. 440 hp.

 

I'd say thats over estimated

 

Yes, and please keep this post to my setup that I asked help for.... thanks...

 

Checked with the XFI268 to see...
HP was about the same, but peaked 500 RPM higher @ 5000
TQ was down 20....

 

oh I would agree.

 

Not by much! The one I built back in the day did not have a tunnel ram and made 423 HP from 312 CID using a single 660 cfm 2bbl TBI unit.

 

I dont believe that

 

Should I mention it had a dual plane intake manifold on it.

Holley 2" bore Projection TBI intake, 427 big block truck throttle body
280XFI roller cam, 1.5:1 full roller rockers, and ported ZZ4 heads
0.040" over 305 with 10.7:1 compression ratio, balanced, blueprinted, extra windage control, and a crankcase vacuum pump

Head flow @ 28 in/h20 with a 3.75" bore simulator
Lift------Intake---Exhaust
.100------57-------57
.200------123------118
.300------177------162
.400------223------183
.500------229------188
.600------238------193

 

Reason i say that is it bests several builds out there with either bigger cams or better heads

Engine masters challenge had a 305 in it once that made almost 400 hp with a 229/238 cam, ported fastburn 210 heads that flowed 265 cfm

Hotrod supposively got 400 out of their 305 with a 244/244 duration flat tappet cam and vic jr singleplane on ported rhs heads....

 

I think the engine masters 305 had ports that were too big and suffered from reduced power.

I have seen 170cc Etec heads using the performer RPM cam make 485 HP in a 10:1 355 and it had a dual plane intake on it too. Same hp to CID would put a 312 at 426 hp.

http://www.superchevy.com/how-to/pro...block-part-28/

HP peak was at 6,400 rpm with 423 hp showing
TQ peak was at 4,400 rpm with 415 lb/ft showing

EDIT----Every detail of the build.

The 312 is a bored out 305, .040" over to be exact, 10.7:1 compression, ported 463 casting ZZ4 heads, Comp Extreme EFI 280 Roller cam, 1 3/4" primary headers.


Block = 1983 4-Bolt main 305 (14010203 casting), Bored .040" over, Torque plate honed, Decked .025", ARP Main Studs, Align Bored

Crank = Stock GM Forged Steel (3941188), Lightened, Smoothed, Knive Edged, etc for less windage, balanced with the entire rotating assembly

Bearings = Federal Mogul Speed Pro Coated

Rods = X casting rods, Parting lines ground down, Lightened, Balanced, Shot Peened, Weights Matched, ARP Wave Loc 3/8 Rod Bolts, Reconditioned

Pistons = Stock L69 Hypereutetic Replacements, Flattops with 4 valve reliefs, -6 cc, 0.00" in the hole

Rings - Total Seal Gapless rings

Compression = 10.7:1 with 54cc heads, Zero Decked block, .038" compressed head gasket.

Heads - Ported 2004 ZZ4 castings ("463"s), cleaned up in my garage, final "MAX EFFORT" port work performed by my buddy in his machine shop, .100" longer valves than stock (1.94/1.55 Under Cut Stems, Swirl polished), 5 angle valve job, Forget the exact spring but they are meant for the cam and .100" longer than stock valves, .600 lift compatible. I had to use longer than stock push rods as well. Machined heads for Comp Cams guide plates after opening up pushrod holes in heads. Gasket matched to a Felpro 1206 (1.34" x 2.21")

Head flow @ 28 in/h20 with a 3.75" bore simulator (engine has 3.776" bore).
Lift------Intake---Exhaust
.100------57-------57
.200------123------118
.300------177------162
.400------223------183
.500------229------188
.600------238------193

Camshaft = Comp retrofit roller XFI280-H13 (280/288 @ .006, 230/233 @ .050, .576/.570" lift with 1.6:1 rocker, 113 LSA, 106 ICL) Cloyes Double roller timing set

Intake Manifold = Holley Projection TBI for "OLD" style heads with the same bolt angle. This intake is a dual plane, high rise, with 2" bores. Gasket matched to the Felpro 1206 intake gasket

TBI = TBI unit off of a Heavy Duty 7.0 liter TBI truck, 68# injectors at 32 PSI, 2" bores, thinned throttle shafts, radiused the entrance to the bores, sitting on a 1" tall open center TBI spacer, 720 CFM @ 3.00 in/hg

Headers/Exhaust = Hooker Super Comp 1 3/4" x 3.5" meant for a mid 70s Camaro with a 350. 3" duals with X-pipe (not used on dyno)

Ignition = Stock GM HEI EST small cap distributer (computer controlled) with MSD coil, MSD Module, Moroso Ultra 40 wires, AC Delco Rapidfires @ .045"

Oil System = Moroso Blue Printed Oil Pump w/ Pickup, Moroso Steel Shaft, Moroso 5 quart pan, Moroso Oil Control Kit, Mobil 1 5w20, 70 PSI Z/28 spring

Crankcase Evac = LT1 style Electric AIR pump pulling a crankcase vacuum of about 6 in/hg.

ECM = RBob's EBL with lots of tuning. 34* total advance @ 2,800 rpm.

Dyno Numbers (all rounded to the nearest whole number for simplicity)

RPM------HP----TQ
2,400----147----323
2,600----166----336
2,800----185----347
3,000----207----362
3,200----223----365
3,400----238----368
3,600----263----384
3,800----281----388
4,000----301----395
4,200----322----403
4,400----347----414
4,600----363----414
4,800----378----413
5,000----382----401
5,200----393----397
5,400----401----390
5,600----410----385
5,800----417----378
6,000----421----369
6,200----422----357
6,400----423----347
6,600----419----333

That is 423 FWHP @ 6,500 and 415 ft/lbs @ 4,500.


The TBI unit was actually a HD C60 series Big Block Truck unit. It has 2" bores with the odd Delphi style injectors in it. 68# @ 32 psi was used to get in the fuel. RBob's EBL was in control of both the fuel and timing.

 

The heads in my build and the Etec170s are a very close match and I had more compression. My cam was slightly smaller in duration, but on a 1* wider LSA. They installed their cam at the same 5* advance as mine.

 

Rockers... I think these will work...
Comp Ultra Pro Magnum Rockers...1.65
# 1803

Heads have dual springs, good for .6 lift.
With the XFI cam above, and 1.65 rockers, lift will be intake .5775, exh. a bit less.
TF heads have guide plates, so I don't need self aligning.
TF heads have ARP studs, 3/8"...
I do have center bolt aftermarket valve covers, no baffles... (Street & Performance TPI Style)
These rockers look to be skinnier than the aluminum (since they are steel).
TF tech said I need narrow, but TF PDF shows standard aluminum ???
I think the valve covers are taller than stock... I need to check..

Anyone see a problem with these rockers / heads / valve covers?

Thanks,

Rafael

 

They should work with centerbolt covers. I believe i ran tall centerbolts with pro mags when i had afr 195's and my 383

 

Well... turbo header has been sold...
Buying 334 stroker kit soon...

I did some more CamQuest stuff...

Still with 305 (not 334) at 10.1 compression (actual will be 10.3)
It spit out 330 hp and 418 tq..... And also not taking into account, Edelbrock TPI base ported to AS&M Runners and Ported Plenum...

I go the XFI 260 cam, Ultra Pro 1.6 Rockers....

 

334 i would have gone xfi 268

 

Actually, earlier in this post you said 260

My bad, in reference to the 305...

335TunedPort is using a similar cam with same RPM specs... 1200 to 5200....

 

Yeah when it was just a 305 tpi. 334 stroke will take abit more cam so you could get the 268 and be good to go

 

As noted 335TunedPort is running the same RPM range cam as the 260 (though his is not the XFI and has lower lift)...

The 268 cam's RPM range is 1800 to 5800... not that a better breathing TPI intake can't rev a bit more, but the 260 cam worked for him.... he ran a 13.4 with slightly ported stock TPI heads and untouched base / runners / plenum....

 

A few more notes...

The 334 kit boost compression to 10:1 with stock 58cc heads.
335TunedPort noted he's running 93 octane with iron heads and not had a problem.

The Trick Flow heads are 56cc, which would boot compression to 10.3:1
And they are aluminum...
I was calculating dynamic compression of about 8.6.
If I retarded the cam a few degrees, this would lower the dynamic compression a bit and also move the power band up a few hundred RPM'S, closer to the 268 range...

 

Got the 334 kit in the mail... box was HEAVY!
Returning the XFI Cam to Summit and getting another one down the road...
The Dynamic Compression was 8.6 and I want to keep 93 octane friendly...
Maybe I'll have a custom one made...
The 260 RPM range was 1200 to 5200
the 268 RPM range is 1800 to 5800
Maybe I can get one dialed in for 1500 to 5500.... good idle and a 93 octane friendly DCR.

Rafael

 

268 be fine lol 8.6 dcr should be ok on 93

 

Been doing comparisons between the XFI 260 and XFI 268 on 305 and 350 engines...
The 260 has higher Tq by 11 - 14... compared to 268 (peak & average)
The 268 has higher Hp by 1 - 3.... compared to the 260 (peak & average)
They both start dropping at about 5500... (which is fine, it's TPI)
I'm leaning towards the one with more tq...

I found the cam that TunedPort335 is using...
264 HR 12
Besides lower lift than the XFI260, the duration has an additional 2 degrees, the LSA and Intake Centerline are 1 degree different.

I think if they can custom grind the 264 with higher lift (being it has 2 more degrees of duration) it should lower my DCR...

 

Hey luvofjah

Of topic somewhat, I have to say you managed to get a thread started about stroking a 305 without having a hijacker tell you how bad a person you are for not putting in a 3*0 cid engine. Kudos to you. Props to you Orr89Rocz and FAST355 for sharing your knowledge on his build as you addressed his questions. Wish this happened more often when someone wants to know what to do with a 305. Truly professional and mature. Thanks

 

That's only cuz it says 305 in the title...
You missed the thread where it says 334, and everyone came in to say not to do it. Here is that one.

https://www.thirdgen.org/forums/tech-general-engine/711282-334-305-stroker-options.html

I am going the 334 route... sold my turbo header, and bought a 334 kit, I did return the Comp Cams XFI cam, and we'll get something custom down the road.

 

Yea I did notice those other threads before posting here. I almost didn't post my comment because I thought it refreshing to just see tech info being shared. I have 2 Lb9 cars (one had a L98 with it when I got it, I still have the original engine) and at least one of them may likely get this type treatment. Before I embark on that however I would like to be involved in or at least see a good technical discussion with competent folks like Orr and FAST that know what the heck they are talking about while respecting your decision. I'm anxious to see how this turns out for you.

 

I'm excited, but it might take a while
TunedPort 335 ran a 13.4 with 2.77 gears, stock iron heads (slightly ported) and untouched TPI intake... His cam had .48 lift...

Since the compression goes up, that helps...
Stock is 10:1 with 58cc iron heads.
Mine should be 10.3:1 with 56cc aluminum heads.
The cam I want to get will have .56 lift, not .48.
The heads, with 175cc runners flow 243 or so CFM, 1.94 in & 1.5 ex. valve sizes.
With ported Edelbrock base to match the Large Tube AS&M Runners and ported Plenum, I'm excited to see the numbers...

Rafael

 

It will be a fun motor. I wish i could stop spending money on my turbo car and build my 305.

I will just be adding a turbo to my stock 305 for now. Plan on stock heads with cam upgrade and intake swap later if turbo stock 305 works well.