Not sure how you managed to get that low on power. Theres stock rotational 305 engines (with dished pistons) on the same heads, headers and a slightly different cam getting 360hp. Super Chevy has an article on one with a dyno sheet. At the dirt track here, mind you this is a staye 3 build, the 5.0L NA engines in the sprint cars are making 500 at the crank. Theres stage 3 334 strokers in the 650hp range, again naturally asperated. Those builds run $15k in parts but still... Just over 300hp at the wheel on a 334 stroker with .6 lift and 56cc chambers seems like you have a problem somewhere either mechanically or in the engine's design. Those heads flow 245cfm out of the box at 0.6 lift... They're capable of 400's at the crank without any port and polish work. Who blueprinted your engine? Perhaps you dont have a proper fuel pump or delivery system to give it more. Did you use the stock sending unit or something? Did you put a massive cam in there without compensating the dynamic compression loss from it via your gaskets and deck heights? Theres equations you are supposed to be using to figure out those numbers, they are very important when changing the dimensions of a rotational assembily. Your static might be 10:1 but on a massive cam, your dynamic (compression when cam and vve events are factored in) but be 7:1. Thats partly why its said that a cam can be too big. Aside from moving the power curve up to the top end, it hurts performance by effectively decreasing compression when the engine is in motion. The higher IVC degree, the lower the dynamic will be. When you put a drag racing cam in an engine, youre supposed to deck accordingly and use the head gasket thickness and bore to fine tune. You can also use chamber size and piston CC changes to offset it, but if you already have those on hand, deck and gasket is the cheapest way to handle it.

For the intenet in general btw, that cant stomach building a 5.0l engine... Google the Agera-R's engine. Its a 5 liter with the same crank dimensions and nearly identicle bore, twin turbo, and they make anywhere from 900-1300hp depending on fuel choice, which is taken into account in the ways mentioned above when you order one. They build it to spec based on your fuel selection. 5.0L engines are nasty when you have an engineering degree and know your stuff. Yes a 5.7 is going to make more. But price per HP, the 305 usually is in a class of its own. Its also a snappy engine compared to the 5.7 because the rotational assembily is lighter, via the smaller pistons. At roughly 6-7% lighter, which adds up to a signifficant ammount when you take that gram difference and multiply it by 8. And that means not just quicker revs, but higher revs, before a piston arm starts getting mad at your foot. Forces for any given velocity are lower becauee it weighs less. Imagine swinging around a 1lb hammer and a 0.75lb hammer. Which one is easier on your arm and quicker to get moving? This is all granted your valve train can handle it. Dont neglect spring choice. Thats just as important as anything else when designing an engine.

 

wow devwolf. gold in that post. would take me a month of full time studying to catch up so some intelligent questions could be asked. keep posting and help us 305 guys show how it’s done.

 

360 flywheel hp on engine dyno with no accessories would be close to 300 whp on a chassis
dyno. Maybe even bit less. His numbers arent bad

A low 11 sec superstocker 305 makes 290 whp lol. I believe speier racing did one that made 360’s flywheel on stock castings that were cleaned up by him. Getting power out of a 3.78 bore without an ls style valve angle is gonna be tough. You just cant get valve size in there, no room

 

How is the idle with that cam?

 

Fully Blueprinted so the cam tunnel is machined to blueprint along with the lifter bores ?? And the cylinders are indexed to blueprint ??? Or just bored off the original bores ?????

 

If he had a 305 sure, but its a 335 build. He should be up in the 400hp park with heads cam and headers. And if youre loosing 100hp (25%) at the drivetrain, you my friend have other problems to worry about. Also, youre assuming the 15-20% drivetrain loss. That number is an internet myth, and its highly dependant on not just the drivetrain but the geometry of where its mounted as well. I've had a car lose 6%, ive had a car lose 8%, 11%, never 15, and certainly never 20 or 25%. That would idicate a problem somewhere that you should probably take a look at before driving it. Unless you put a diesel drivetrain behind your stock gas powertrain or something. Thise things from rotational weight alone take up a lot of torque in the low RPM. But other things could be bad bearings, pitted gears (debriss) that are resisteing slightly and turning an excessive ammount of rotational torque into heat via flex. There are a shitload of factors but here he would be loosing about 20% if he was making 360 at the crank, and thats a problem despite the bad numbers to begin with. The transmission and dif alone can bleed off torque numbers iof theres a problem. Lets say you have an 'ok' trans but the diff is old and worn, has large ratio gears (so lets say 3:1), and you use big diameter tires. Well the torque from the drivetrain is going to put a lot of force on that ring gear and carrier and each tooth is passes is going to flex just a tiny bit. Then it rebounds once the tooth is out of mesh. This generates heat. Take a paperclip and bend it back and forth rapidly. Not far, just little bends. Now put it up to your lip. Feel that? Thats how a transmissions makes heat. The engine and clutch add to it, but heat conversion is the major generator.

Remember you are assuming its a 305. Its a 334 stroker, big difference in power. In a stage 3 build, you might expect to make 1.9-2.0 hp / in (or highter if its forced induction). They mare very efficient engines when built right. Well 29 inches in that engine equates to 55-58hp. That might sound like it isnt much, but do the math at 1.9-2.0hp/in on a 305. It gets up there quick doesnt it? Look, point being, 360hp on a 334 stroker build, even without changing compression and even if you had a pretty bad cam for it, is very low. Low enough for a mechancial engineer (8 years, 2 bachelors) that does endurance small bore engines professioanlly to say something is wrong here. And I strongly suspect its a combination of a bad cam choice and a stock fuel system.

 

Theres no need to troll the guy dude. If he says blueprinted and the first thing that goes through your mind is the cam journals and lifter bores, you sir, have a problem. Not him.

 

Last Tpi 355 I saw dynoed was in 2000-2004. Cant remember. Full upper edelbrock with AFR heads and dont remember the cam. But it was built by Reids in Whitman MA. Its dynoed at 368hp. Sounds low and unimpressive yes but it made 480ftlbs. If it's on a engine dyno fuel system is up to spec. The rails are not a restriction. The limiting factor is the intake. You are going to be hard pressed to make 400+ on a stock type TPI runner system. It's made for tq and street driving. I think the numbers are right inline for what it is. To be honest even if you take the 300rwhp number as a gauge. What does a factory 305 dyno at? 160-180? Take it into perspective.

 

I aint assuming its a 305 i know exactly what it is and what power it should make and i can tell you those numbers are not terrible. Dyno numbers dont really matter much anyway. I dont think ppl understand what it takes to get 400 whp lol. Anything in the low 300’s for a tpi style build with runners that long is doing pretty good

and no dyno loss is not a internet myth. It varies on car type and transmission type and dyno type, among many other things. From what WE have seen at the local dyno and cars i have tuned and ran at the track to verify, 15-16% loss is acceptable for some automatic trans/10 bolt type drivetrains in these cars and most manuals 10-15%. Some looser converter stuff we see more like 20-30%. Just my experience

theres probably 10-15 whp more just by locking up the converter

 

My locked converter 4L85E 2nd gear(didn't want to throw the driveshaft) pull and 9.5" semi float 14 bolt was about 30% loss in my Express van. Current 14 bolt 10.5 loses about 33%. Lost about 10 hp from the 9.5 to 10.5 swap. So yes driveline losses can be high. A stock F-car LT1or LS1/Auto/7.5 loses about 18% and the stick 15%. B-car or Vortec truck with a 4L65E/8.5 loses slightly more.

 

OK. Looks like alot went on in this post that I completely missed out on. Anyways.....


I'm baaaack with the Superram results. I've made a few changes to the engine since this thread started. I sold the TPI plenum and SLP runners and replaced it with a ported superram. Divided runner length was shortened by 1.5" (17" total combined intake runner length from top of port to valve) and CSA opened up to 1.78". The same base manifold and throttlebody, already from a superram setup, were reused. Only the plenum and runners were changed. The base manifold itself was not re-ported over what I did 4 years ago or even removed from the engine during the swap.

I also added a GZ Motorports vacuum pump, pulling 8" of vacuum at WOT on the crankcase. I did a bit of an ignition upgrade as well by adding a Pertronix Digital Mobile HP ignition box mounted to the passenger side of the dash inside the car. Lastly, I installed a set of Hawks ram air boxes. Obviously not really worth anything on the dyno, but when the car is moving they certainly help a bit.

See the new dyno chart. It didn't pick up what I thought it would in the torque department. The highest reading we got was 373rwtq which is a 10wtq gain. It did yield some respectable gains in the horsepower department though. It gained roughly 25rwhp peak but look at the top end. It picked up nearly 50rwhp at 6000rpm. The below chart is a direct comparison of the TPI run vs the superram run.



Good gains, but what gives with how it behaves after peak? It peaks (Still at the same RPM. I think a 5200rpm peak on a small bore motor is pretty low and a good indication that it has more left in it), then drops slightly and just sort of coasts there making good average power all the way up to 6100rpm where it slams into a wall and stops revving. I still think it would really benefit from a different cam grind and another 2" of runner divider removed. Any idea on tweaking the duration and LSA numbers? 222/230 @ 050 and with how it's been reconfigured, I'm leaning towards not enough duration on the intake side now. Also wondering how a 112LSA would work in comparison.

Also, with some more adjustments still needing to be made to the fueling, with the last two pulls we did one with the converter unlocked, then the following pull locked the TCC. The unlocked pull it put down 335rwhp. The locked pull it picked up 10rwhp and laid down 345, but this small gain in peak was not reasonable due to the susbstantial loss in midrange from the lack of converter flash. Factoring in a conservative 15% drivetrain loss from the above posts, that's roughly 410hp/440tq at the crank with all accessories hooked up and the car exactly as it is going down the road. That should give you guys an idea of how much parasitic loss we're looking at. I'm also thinking that the TPI snorkel itself is a restriction at this point in the pinch area. Doing a STREET pull with real MPH and wind, the MAP begins reporting a kPa of 101 at 2500rpm but then by 5000rpm, that reading drops to 97kPa. Doesn't this indicate a restriction in front of the throttlebody if it's pulling a slight manifold vacuum? Especially with a true ram air setup? I do have a spare TPI snorkel I got lucky and yoinked off a yard IROC for $5. I'm planning on trying my hand at fabricating a high flow TPI lid.

 

nice to see a different build, who cares what haters have to say? How many 334s are out there?
Those are stout tq #s. Easy to turn ones nose up wiht all the posted dyno queen web stuff but in real life thats a good running car light to light

Bullydawg just came across this....health took me away from the game among other things for years now...starting up a project here and there as I have a garage at my disposal. OP how far did you take that base ? (those are NOT fun).

 

The Accel casting is decent to begin with. I didn't get super involved with it. I just ran a flexshaft into the ports and smoothed the turns out a bit, then opened up the choke point some, matched the ports to the head and ran through it with a flexhone.

 

Waaaait a minute....

After reading all that... devwolf, are you the guy that was on the groups several months back talking about building a 334 with "chromoly cylinder liners"? That just all came back to me when you mentioned that you had a fully built "chromoly bottom end". You mean 4130? Your posts honestly seem like there's a bit TOO much to them. You'll blow the webbing out of that block LONG before you reach the safe limits of a 4130 crank.

 

Since I had to go back and refresh my memory, here are his build specs:

Engine specs are as follows:

- Virgin 40k mile 305 roller block out of a '92 TBI bird (Bored .030' over)
- Fully Blueprinted
- Eagle 3.75" stroker crank
- Eagle 5.7" 5140 forged I-Beam rods
- ICON 2618 forged pistons
- Ring gaps are set at .020" top ring and .022" second ring to safely allow nitrous/boost. Piston to wall clearances for use with 2618 forgings are set at .0055"
- Trickflow Super 23 175cc heads. 1.94/1.50 valves. No porting done. Bolted them on out of the box.
Here is the flow data:
https://static.trickflow.com/global/...75%202014c.pdf

- Comp Cams 918 beehive springs @ correct installed height.
- Calculated compression ratio is 10.5:1 static and 8.6:1 dynamic.
- Comp Cams custom grind roller cam. 222/230 @ .050. 110LSA. Lift is 569 Intake and 531 on the exhaust thanks to a 1.6/1.5 split ratio full roller rocker arm setup. Short travel roller lifters as well. The cam out of box spec'd in retarded 2.5* from ICL so I advanced it by 2*.

This post had my attention before - now it really does since I also have a 334. https://www.thirdgen.org/forums/tech...ml#post6206874
FireDemonSiC, you said CSA opened up to 1.78". You are talking Cross Sectional Area at the choke point of the heads, correct? Notes from my build:
World Products 305 Torquer 58cc #4265 with 2.02/1.6 valves
175.2 (now) cc intake / 65+ cc exhaust / 58 cc chambers
The intake ports “choke” point now measures .95 x 1.90, which equals 1.805 sq in. and would allow 5903 rpm for the 334. (Wallace calculator)

Your engine is more radical than mine, but the 1.78 sq/in choke point you have is most likely the reason why you hit that brick wall at 5252 rpm. This is what Wallace calculates for yours: Your RPM computed from your Cross Sectional Area of 1.78 and Bore of 3.766 and Stroke of 3.75 is 5,821.32 .

 

Probably does need abit more area to peak alot higher but i havent run it thru any programs. Cam seems ok for the rpm range. The shorter runner intake allows it to hold on up top, all that extra power past peak will make for a much faster car than the tpi intake once you adjust shift points to use it

 

Full manual VB, so it shifts when I want

It is getting a bit tiresome though and I'm planning a K-Case build. That's why I haven't sprayed this engine yet despite only needing to open the valve and press the button.

As for CSA, that 1.78" measurement is for the port in the runners. On the base manifold, I did massage the choke point a little but it still has more left in it. The only way I'm going to the trouble of taking that god for saken intake back apart though is a cam swap, which is attractive at this point since I have been contemplating a 280XFI on a 110LSA.

Thoughts?

 

Meanwhile in V6 land........
...https://www.thirdgen.org/forums/v6/7...ron-turbo.html

Should of went 383 honestly.

 

"Got the final numbers on my Turbo Firebird 3.4 Iron head. 325hp and 334.4 ft lbs at the wheels @ 14.0 PSI."

It's astounding the number of people who can't read...

 

Yeah boost changes everything. I always felt those with 305’s should just put on a turbo, but it is an involved project

 

The car is setup for spray but the trans takes forever to shift as is all motor. I'll be hitting it with a 150 soon enough. All numbers so far have been NA

 

Nitrous helps all things as well lol

 

What are everyone's thoughts on a 280XFI ground on a 110LSA? While everything is apart, I can shorten the divided runner length more and also work on the choke point in the base manifold. I can also have the advertised lift of a 280XFI ground into the lobe for use with 1.5 rocker arms instead of 1.6 for better geometry. Lastly, I can even have it ground on an LS firing order while I'm at it.

 

You have a bottleneck that will not allow your combo to get beyond 5252 rpm. So how will a bigger camshaft help at this point?

You could always do a test with a 4bbl intake & carb.

 

That's why I mentioned modifying the base. Maybe upgrading to a different base altogether. Aren't there other castings like the FIRST base manifold that completely reworks the way the port enters into the head?

The engine revs well beyond 5200. It just stops making more power there. It peaks and then holds within 10rwhp of that peak all the way to 6100. Then completely shuts down. An untouched out of box Supperram was designed for around 5500rpm on a larger bore engine. Something seems a tad off.

No to the carb. Just, no.

 

Serious gains can be had with a first base if it can be used with the super ram upper, but dont think it will work. A welded up base with raised injectors to get more area at the head port entry would be ideal. Or shapen the port entry to help the pathway of flow.

 

Are the runners on a first separate tubes or can they be siamesed? I know somebody who has one....

 

They should be cast type with common wall that can be ported to 1.9” diameter. I think they come at 1.75”. So openig them up some plus elimination of the common wall to siamese would be tremendous

 

Ok. This is coming from someone who is looking to buy a jegs 350 crate motor. Dont knock others stuff. Why dont you take your own advice?

 

I was going to say start looking at the intake piping. Even with the k&n and ram air I still think the neck down is killing it. It necks down to almost 1.5 inches at the pinch points. Maybe
Run it open for one run and see. Or just a dummy 4 inch pipe on the front with filter. I'm doing a custom dual 3 inch y intake that picks up air in both fenders. Good numbers though.

 

I'm sure that the snorkel is posing a sort of restriction. But, it still raises the question of why it stops making power at only 5200rpm and then flatlines at that power all the way up to redline. Is the base really that bad flowing? Or have I simply hot the limit of a 1.94 intake valve and a 175cc runner (Also have a hard time believing that on a 3.766" bore at that low of an rpm). Pulling that intake and selling it to replace with a modded FIRST is going to be alot of work for questionable gains.

I could go for one more dyno run before the year is over. Be interesting to see what it makes with the snorkel pulled.

Everything is supposed to be pretty well matched. Both my heads and the Superram should flow in the 245CFM ballpark. So why is it peaking so low?

 

Its the length of runner combined with intake cross section area limiting peak rpm. It hangs on because flow is there from enough cam duration

alot of race motors do this, they peak at certain rpm and hold power for 500-1000+ rpm after peak

 

Ugh. That's what I was kind of suspecting but hoping not to hear. And I'm guessing the 6100 wall is the cam running out of flow?

On the bright side, I could sell the Superram for over $1000 more than what a FIRST will run me...

 

IT could be pumping loss finally outruns the cam duration and falls off hard after 6100, or it could be losing valve control. Not sure

 

Well, by that logic, it would make the most sense that it's the base then. I never touched it during the swap. Never even removed it from the engine.

I'm half tempted to throw a custom grind 280XFI and a FIRST at this thing now...

 

I think the stroke would match up well to more duration but i havent run the numbers.

 

What I'm really thinking of doing is having a custom ground 280XFI made. Same duration and lift, but the lift ground for a 1.5 rocker arm ratio and a 110LSA.

I also installed a crankcase vacuum pump at the same time I did the superram just FYI since you mentioned pumping loss.

 

Valve float that’s exactly what I was going to say

 

918 beehives at correct installed height. Not saying they're more than adequate. Just saying I used pretty decent springs.

 

Well if you do that it wouldnt be the xfi lobe anymore. To have same lift with 1.5 rocker as 1.6, the lobe profile has to change from the advertised xfi profile. They do have lobes that would do that same lift range and approximately match. Some newer aggressive stuff and the magnum high lift stuff i used to run.

 

Running quick figures, you should have enough csa and definitely enough cam to support more rpm. I think the runner length might hurt it some but not sure of your exact figures and measurements. Pipemax seems to think you should be in the ball park for 5500 rpm. Cam program i have seems to think you got more than enough duration and lift and i would somewhat agree. Throw a miniram or lt1 intake on it and you’d see what i mean lol. Not sure a 230 deg lobe is gonna help here

 

I agree - all your parts ARE well matched. Find the bottleneck.
The only other thing I can think of, and it's a long shot, is that the head airflow is somehow being upset by the small 3.766" cylinder bore and/or shrouding of the valves by the combustion chambers. But I seriously doubt it, because those heads are specifically made for a 305's bore size.

 

If your looking for a restriction in the air inlet try using a vacuum gauge to measure the pressure loss. At idle with the throttle blades closed you should have zero vacuum (atmospheric pressure) every where upstream of the throttle body. Now when you open the throttle the manifold vacuum goes down but upstream of the throttle body the should still be zero vacuum and any vacuum reading indicates a pressure loss/restriction on the air inlet side. What's so nice about uses a vacuum gauge is you can tap into each location of the air inlet track to locate a restriction.

Hope this helps.

 

Good ideas. I like the vac gauge on the inlet side of the throttlebody. Especially since I have the threaded port in my snorkel.

 

FYI, against my better judgement I finally gave into temptation and took to the car to the track this past weekend.

She was hooking and booking until the 700R4 decided to pack its bags and head south for the winter. It was lazy shifting into 2nd and having serious difficulties making the 2-3 shift. After the second pass, I was getting an audible driveline tap/knock from under the car in the bellhousing area coasting down the return road in 2nd gear. After the third pass, I called it a night because the noise was getting louder. Good thing I did because for the entire 70 mile drive back home, 3rd and 4th now sound like a Muncie 4 speed

Below photo is my favorite *overall* timeslip. I'm in the right lane. This was against a coyote mustang and I was doing well until the trans made a complete refusal on the 2-3 shift. It just sat there banging the 6800rpm fuel limiter 3x and I had to completely let off.

Best times I ran were a 1.69 60, 12.85ET and the final pass I managed 107MPH by short shifting the 2-3 and got it to sliiiiiide into gear. Now it's time to put her to bed for the winter and get a proper setup behind this little engine. But, I'm pretty happy. These numbers look promising and the car still has a lot left in it. I was still making fueling and timing corrections when I threw in the towel for the night.

 

Awesome. Nice times Na.

That tapping knocking. You may have ripped the trans mount or tq arm mount. Time for a rebuild maybe. Nice results.

 

Youre doing great...i wouldnt start throwing lopey cams and hacking intake.
If anything leave it be...down the road really go after porting the base (what did you do aside from siamesing) and some minor head work.
Call it good. Those are stout #s from a 334 many 350s arent doing that


Comparing a TPI 334 to a carbed one...meh. This is a st car you got a good combo.

 

Thanks man. I really believe that this car has every bit of 12.5 @ 110+ in it with a transmission that's worth a damn. I'm currently researching to build my own over the winter. I've decided to keep the full manual 700R4 setup. I have a K-Case core I've been hiding for a few years now and am building it with the Pro-Built Pro-street kit. Also highly considering a hardened input shaft and the Sonnax Smart-tech input housing with bolt on backing plate.

As for the intake and the engine itself, Currently trying to figure out why HP will not build above 5252rpm where torque and power converge. After the superram swap, it gained 20hp at peak over the SLP TPI and a substantial 50rwhp at 6000rpm. It did not however, change the RPM at where the peak occurs.

During the transmission rebuild, I am strongly considering pulling the entire intake back off, opening up the base and having it welded at the choke point where it turns into the head so I can substantially increase flow and CSA at the weakest point. Also am thinking of shortening the divider runner length by another 1-2"

 

Doubt it. Trans mount is polyurethane and looks fine from what I can see. Torque arm is also a BMR and crossmember mounted. I'd be impressed if I hurt that

 

Here is the slip from the first pass where I ran a 12.85 @ 105. I didn't leave as hard and the trans still took forever to make the 2-3 shift but this pass I didn't bang the limiter. I did have to completely lift to make the shift.

Fueling was rich way into the 11s (When people say the Dyno loads the engine up differently, they aren't kidding) and the porcelain on the plugs (I put fresh plugs in every pass) was showing some peppering so the timing was too much for the long draw of 3rd in the quarter. I dialed it back from 36 to 34* but didn't get to properly test it before the trans threw in the towel.

Fun fact. My girl was in the left lane and stalled her car

Stay tuned guys. She's going to sleep for now but she'll be back