Extracting max power from 347 stroker

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Author Topic: Extracting max power from 347 stroker  (Read 541 times)

Offline Brunoga

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Extracting max power from 347 stroker
« on: October 16, 2020, 12:34:57 PM »
Wondering if any members can recommend a reliable and experienced engine builder/mechanic who can help me maximise the power from my existing 347 stroker. Iím in Melb metro (north east). Car runs well but looking to do mods that may get more performance and responsiveness from my set up. Currently runs a late model 302 block with eldebrock performer RPM heads and eldebrock RPM Airgap manifold with 1-inch spacer, full MSD 6AL upgraded ignition system, mild crower hydraulic cam and Holley Sniper EFI. Has a strong supra R154 5-spd gearbox and 9-inch diff with 3.7 gears.  Cam specs: duration at 50: 234 (in); 240(ex) , lift : intake: 533 ; exhaust 544 , lobe sepín: 110 (cam installed at 106)
« Last Edit: October 16, 2020, 09:46:12 PM by Brunoga »

Offline Reborn67

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Re: Extracting max power from 347 stroker
« Reply #1 on: October 16, 2020, 03:12:00 PM »
Do you know what horsepower you are currently putting out and how much do you want to spend ?
« Last Edit: October 16, 2020, 03:13:59 PM by Reborn67 »

Online GEOFF289

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Re: Extracting max power from 347 stroker
« Reply #2 on: October 16, 2020, 03:46:06 PM »
You might have trouble getting anything done in Melbourne at the moment but get onto Theo at Pavtek.

https://www.pavtek.com.au/


Offline 6R07K

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Re: Extracting max power from 347 stroker
« Reply #3 on: October 16, 2020, 05:56:36 PM »
Be interested in hearing how you have found the snipper?
Cheers

Ben
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Offline GLENN 70

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Re: Extracting max power from 347 stroker
« Reply #4 on: October 16, 2020, 09:36:39 PM »
Sounds like a good setup now but depending on the cam . You could try a 1/2 inch open spacer and make sure you have a decent air cleaner . Timing should be around 14 at idle and 32 total at around 3,000 rpm . The open spacer will help from 3,000 rpm up . What do you rev it too ? 6,000 max ?

Offline Brunoga

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Re: Extracting max power from 347 stroker
« Reply #5 on: October 16, 2020, 09:49:08 PM »
You might have trouble getting anything done in Melbourne at the moment but get onto Theo at Pavtek.

https://www.pavtek.com.au/

Theo is either too busy or doesnít seem interested in providing some help

Offline Brunoga

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Re: Extracting max power from 347 stroker
« Reply #6 on: October 16, 2020, 09:56:07 PM »
Iíve updated post with cam specs and has a 1-inch spacer between EFI and manifold.

Iíve reached out to Theo of Pavtek but doesnít reply - must be too busy.

Never done a proper dyno but might do it after lock down.

With 5-spd I am told changing diff gears from 3.7 to 4.11 will improve performance response (not power).  Was contemplating whether 195 afr heads and junior victor manifold might help - looking for more torque power up to 5,500-6,000 (max) rather than high end rev screamer to feel power.

Sniper has been overall great despite some minor sensor issues early on - sniper produces an amazing turbo-like whistle which is pretty good. Cold starts are the best with the holley sniper - and Iíve matched it with an after market fuel tank with electronic fuel pump inside.
« Last Edit: October 16, 2020, 09:59:51 PM by Brunoga »

Offline GLENN 70

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Re: Extracting max power from 347 stroker
« Reply #7 on: October 17, 2020, 08:19:40 PM »
Ok if you want more torque change a few things around .  1st take off the 1inch open spacer and try that . That will give the engine more torque and still good to 6,000 rpm . Then you could try a 1inch four hole spacer for even more torque and might drop the power range to 5,500 rpm .  Yes 4.11 gears will increase performance through the rev range .  A Victor jr intake will only work at the higher rev range and lose torque
.

Online GEOFF289

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Re: Extracting max power from 347 stroker
« Reply #8 on: October 18, 2020, 08:03:28 AM »
Unless you want to wring its neck every time you drive it I reckon a 4.11 diff will be too low with a 5 speed for practical every day use. It'll certainly wake it up but first gear will be rendered nearly redundant.

Offline Brunoga

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Re: Extracting max power from 347 stroker
« Reply #9 on: October 18, 2020, 10:43:48 PM »
Thanks !!

Offline HEVEN67

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Re: Extracting max power from 347 stroker
« Reply #10 on: October 20, 2020, 01:22:13 PM »
Be interested in hearing how you have found the snipper?

 I read it in one of the magazines holley stopped making the sniper due to a large number of recurring issues,
They are optioning you to get the multipoint EFI instead.
I have the multi point on my new donk.
Luvhev
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Offline 6R07K

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Re: Extracting max power from 347 stroker
« Reply #11 on: October 20, 2020, 08:22:57 PM »
I read it in one of the magazines holley stopped making the sniper due to a large number of recurring issues,
They are optioning you to get the multipoint EFI instead.
I have the multi point on my new donk.
Luvhev

Not that I can tell, but plenty of bad stuff on the web. The way I'm thinking at the moment is its simple to set up, but a lot of people have issues getting the specifics correct. Can't blame the sniper if you don't give it a good key on 12v source or if your engine has other issues already like vacuum leaks etc etc.

Mostly what I'm interested in is running it returnless with the direct fit in-tank pump. Read all the various things about hot start issues which I think can be sorted with a few tweaks but concerned whether returnless will result in hot fuel in Austrlian summer conditions!
Cheers

Ben
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Online Dwayne

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Re: Extracting max power from 347 stroker
« Reply #12 on: October 20, 2020, 08:58:04 PM »
I'm in the middle of dropping a BA Falcon pump in a 22g tank for mine.


There's also a few drop in options now like these Holley returnless pumps
https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/fuel_pumps/muscle_car_efi_modules/parts/12-305

Offline 6R07K

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Re: Extracting max power from 347 stroker
« Reply #13 on: October 20, 2020, 09:51:21 PM »
Considered the holley replacement tank but liked the 12-305 option best if hot fuel wasn't going to be s problem in summer.

Sorry for the thread high jack...will be quiet now.
Cheers

Ben
Lifes short, play hard.