CAN YOU TAKE A 327 CRANK AND PUT IT IN A 350TPI AND HAVE IT RUN RIGHT CUZ OF THE SHORTY STROKE

 

I guess its possible with the use of some longer rods...


But why the heck would you want to do it???

 

If your making a 327 you would have to buy 327 pistons. I don't think a stock TPI and a 327 would be a good match up you need to build a 383. Now that would be a torque monster. 327 aren't good at pulling heavy cars around put it in a 66 nova now your doing something.

 

You probably cannot even fit the crank it the block unless it is a large journal crank.

 

except for the last year or so the 327s were small journal cranks. like was said you'd also need 327 pistons since you'd have a 327 and if you have a SJ crank you'd need SJ rods to match. it'd be cheaper and easier to use a 350, not to mention you'd make more power.

 

I think it's a great Idea. You should get great low end torque for a small engine from the TPI and since the airflow requirements are less for a smaller engine you should see more rpm than a 350 TPI I think with careful cam and head selection this could really kick ***. I would rather improve the induction on a larger motor than build a smaller motor to suit my induction but I think it has potential. Don't listen to everyone that tells you how much torque you need you can only burn so much tire. Besides LT1's and LS1's arent faster because they make more torque, they don't, it is because they make more horsepower up top.

 

What a great idea! Spend more money to get less cubic inches. Less Cubic inches=less horsepower. Spend more to get less. What a concept.

 

 

damn that's funny, did you really mean it or were you joking?

 

It's a better idea than putting LT1 heads on a 305, or doing anything to a 305 for that matter If you do the math it has good potential for a street motor idle to 5,500
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horsepower is a mathematical equation of rpm and given the airflow capacity of a long tube runner system a 327 will get more rpm. More cubic inches=more torque and the TPI already generates more than enough usable torque that I'd be willing to trade some for rpm and horsepower

 

I cant even believe you would be trying to use an argument like that. IT WILL NOT MAKE MORE TORQUE THAN A 350! Will not happen. Put the same TPI on a 350 and get more. Its not that hard to figure out.

 

are you triing to move the powerband towards the top of the rpm range and make it rev quicker with a smaller stroke? cause thats what youll do, i like cars that have good bottom grunt but they are fun as hell with good high rpm power.

 

can you please point out where exctly I said it will make more torque? It will make very acceptable torque but not more by any stretch and with that I'm done. I gave my answer read: opinion on the question.

 

Do you know anything about tuned port injection or intake acoustical (impedance) tuning? It is solely a function of rpm, and runner lengt,h engine size plays no part. So a 327 and 350 will be acoustically tuned for the same rpm.

 

Do you know anything about engines? Do you really think the stroke will have no function of the induction tuning? If that was so all aftermarket runners would have negative affect. Siamese runners would also have no affect. Do you beleive everything you read. The acoustical tuning is a GM sales pitch that you obviously bought. Get out in the garage turn a wrench on something and prove me wrong. I thought this site was useful and informative, It's a bunch of bickering 3rd graders.

 

It is about tech, and your last post contained practically none.

Induction tuning is about RPMs. Stroke has nothing to do with it. The pulses in the induction system are produced by the closing and opening of the intake valves. When the intake valve closes, the air that has been moving in the port must suddenly stop. This produces a shock wave that is reflected back up the air column in the port until it reaches the end of the port (i.e., the plenum), and is then reflected back down toward the intake valve. If that pulse/shock wave arrives back at the intake valve at the same time as the valve opens again, the effective pressure of the air column will be higher to drive air/fuel into the combustion chamber than it would be if the wave front was somewhere else in the intake port track. The speed the shock wave moves is affected by the fluid (air) density, which is why the factory put a water heat exchanger at the throttle body to keep it more constant. Therefore, the "tuning" is affected by the temp of the fluid (air) and length of the runner track. It produces a fairly narrow effective RPM range, which the factory chose to make fairly low for the purposes of fuel economy and "seat-of-the-pants" power feel.

Is that tech enough for you?

 

I have been designing and fabricating tuned runner/plenum intakes for over a year now. I have been working on the University of Idaho's Formula Society of Automotive Engineers (FSAE)racecar. I have hundreds of hours building and dyno testing intake manifolds for the car. I have written several FSAE and SAE papers on the subject. I have developed and produced several computer simulation and math models on the subject. The intakes that i have designed have made 10-15% more peak power, while still increasing the average hp over previously designed intakes.

So yes i know a little about the subject.

It is a very complicated subject, but five7kid covered it perfectly for your simple mind.

 

I wonder what the reason is that "z282slo"'s car is, "2slo"...

lol

 

well i stil think its a cool idea.. a 327 TPI is a different motor that u dont see everyday. its better than a 305 or 335 stroker because it will have a bigger bore and allow for more air flow/compression.

i would love to build a dz302 like motor but throw on a superram or hsr and rev that thing to the moon

TPI is a great setup for 305-327 motors.. full aftermarket TPI flows more than enough to feed those motors to 5500-6000rpms.

 

Actually smaller bore motors allow for more compression. And are more efficient combustion designs. The may restrict airflow slightly due to the smaller valves allowed, but are a more efficient design.

Tuned runners are not about flow,flow doesn't matter after your reach the tuned region. All power is killed once you pass the tuned rpm region dictated by the runner length. Once you do this you are in an anti-resonance region. Where the airflow is actually forced away from the valve by the reflected momentum wave. Physically no more power can be made. That is unless you spin the motor high enough to get out of the anti-resonance region. This very bad and is why TPI falls flat on its face after 5000rpm.

Does anybody know the effective runner length of a TPI intake?

 

Isn't it like 3 or 4 feet??

 

I believe its 24" from the Valve seat to the mouth of the runner in the plenum.

Orr89RocZ, Read what MeLeigh has been writing.

To summarize, the original poster asked if he put a 327 crank in a "TPI 350" if it would run right. The answer is mostly "no", because unless he got a last-year 327 crank, it wouldn't fit. But even if he DID get one that fits, he would be spending money and doing work to make his car slower than it is w/a 350 now. As "cool" as you think the idea may be...

-Tom

 

i do hear what your saying... runner length and all the flow characteristics and all that good stuff.


its just that alot of the dyno graphs show that smaller motors like the 305 and 335's TPI motors can make good power to 5500rpms and maintain that to about 6.

put that same intake setup on a 350 or better yet a 383 or 406, and peak power drops to about 5000rpm for the 350's and 4000-4500 range for 383+ with drastic dropoff after that. i know the runner length has alot to do with the flow process and power making but smaller motors dont need that much air and a TPI is good for smaller motors. hell it was designed for the 305, never ment to be put on the 350. LOL


and sometimes ppl dont want to just go fast and make power.. sometimes it's great to be different and do things that no else has done. thats what i'm all about.. i dont wanna copy ppl.. i wanna be unique

hmm thats interesting.. i been hearing alot of talk about how the 305 sucks compared to the ford 302 because the small bore of the 305. smaller bore does hurt flow, but what i ment by compression is that you can run abit more compression on bigger bore motors with less detonation worries.. or atleast thats what i read somewhere on this board.

 

Thats wrong its actually the opposite. Smaller bores are less detonation prone. The smaller bore means that there is less piston and combustion chamber area. Which means that combustion occurs faster and more completly. Also with a longer stroke the compression is more violent, meaning it occurs faster so there is less time for detonation and the mixture is much more homogenized and turbulent.

 

very interesting.. thanks for clarifyin that for me. it does make sense.

isnt it more in the rod length too, as longer rods spend more time at top dead center than shorter ones?

 

Yes, but rod length has much less of an effect because the difference in length is small. Also rod length doesn't change the piston speed much in between TDC and BDC.

 

Well you guys sure do sound like you know what your talking about. So maybe you can help me out by selecting a custom grind cam profile for my HSR 327 setup. Right now I'm running hyd tappet lift cam and I want to upgrade to a hyd roller with rev kit and try to get my shift points to 6500 rpms. I'm just curious to see how much hp and tq I can get out of the engine.
My car currently has:
3000 stall
3.73 gears
22lbs injectors I also have 30lbs too.
950 commander ECU
58mm TB
1 5/8 headers and catback
331 ci engine with bigger cut out valve reliefs
9.6.1 comp w/ TFS heads also have AFR 68cc competition port heads.
planning on raising the comp to 10.1

This was going to be a 383 build up and it still is but no time soon though and I already had this engine built just sitting around. I read a lot of articles of ford 302's making over 400 hp at the wheels all motor. I was wondering can I accomplish this with a chevy 327 with the right cam and my AFR heads? Or atleast come close to it.

 

maybe the ls1's make more torque up top. that's part of it. they have a much much greater power band so they are able to put more torque to the ground on a time/torque basis. and so forth.

l98 torque is like a quick peak going into a huge valley. ls1 is just flat

 

i've played with accoustics a few times and I can tell you right now runner legnth does make a big difference in what point something resonates. as far as it being just a GM sales pitch how come some cars come with variable intake runner length, or so forth.

it's not the stroke thta is effecting the induction as much as port runner diameter and length. the resonance is caused by frequency. different frequency sounds have a different wave length. lower pitched sounds have a longer wave length and need a longer runner to go into resonance, the opposite for shorter wavelengths. stroke doesn't change wavelegnth or anthing like that.

 

big bore and detonation is actually the opposite. your more prone to detonation this way. the longer it takes for the full air/fuel mixture to burn the greater the chance of detonation. with the larger bore it takes much longer for the fuel to finish the burn which in turn creates more time and more chances for detonation to start.
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you see what maybe a 50 ft/s or so peak speed difference. but again that is peak speed. avg speed is the same it's just that very very brief situation
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guess you guys already talked about a lot of what I have said. oh well