318 and boost...

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69CudaFan

69CudaFan

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So because I had some time on my hands, I started wondering to myself if a low-mileage 318 with their notoriously low compression would lend itself to take reasonable amounts of boost. I know that detonation is the engine killer, so I guess what I am thinking is a "budget boost" type of build. I know that forged pistons, etc. would make for a much more stout package that could take a lot more boost, but I was musing that a low mileage low compression 318 with enough fuel and and a colder plug might be able to take it. The other thing is that if it were grenaded, there are more than a few replacements running around.

I was debating putting this in the FI forum or here, but since I am talking only one type of SB engine, I thought that it was more appropriate here. Are the rings and ring lands far enough down that the piston failure is less likely? This is based on the assumption there is enough fuel and timing to keep detonation at bay.

I will grab a cup of coffee and see how this develops. :coffee2:
 
The low dollar aproach would be to lock the mech weights in your dizzy, so you can control your total advance more easily. That plus a good water injection set up.
Then stick to a reasonable boost figure.
For a standard engine, I'd look for a none to large turbo, and go for fast spool, with a nice safe rpm limit.
 
The short answer is YES.
Low Compression (anything under 9.5:1) will stand upto 20ish PSI...with NO Modifications to a Stock Longblock....above 20 psi, a set of MLS (multi layer steel) head gaskets and ARP HeadStuds and the longblock can go as far as you can supply the fuel for.

Like you said, 318's are practically FREE....its worth the venture if the financials can support it.

I know of more than (3) single turbocharged 88-93 5.0L Mustangs over 600hp on stock internals....that drive to the track and rip 10's (one mid 9's) street legal on Drag Radials.

If a 5.0L Turd Block can stand it....why cant a SBM?

Here's a single turbo dart 318 on youtube:
[ame="http://youtu.be/B74ACQbowas"]302 Found[/ame]
 
I am not sure I am convinced that the stock cast pistons will handle more than single digit boost...anyone able to make reliable power on stock pistons and how far have you pushed it?

BTW, as this evolves, the more I think the FI forum would be a better venue. Perhaps a Mod can move this to get more "duty expert's" input.
 
Your wish Is my command, into a better forum.

Forced Induction Mopar
 
You may or may not be surprised what single digit boost numbers will get you in terms of HP addition, but for my daily driver, I was happily surprised with my 6PSI setup on my bone stock 73 /6.
I'm guessing it's not a racer because of the "budget build" terms, but there are some things that you just can't skimp on...wideband setup and fuel delivery to name a couple, and mine is about as low budget as one can get...that's why you wont see any pics ;)
 
I was just thinking the same thing about doing a single turbo 318 build, I was given a dart with a for 9 inch setup with a built 727, my thoughts were just to learn how do the fabrication myself and do a stock rebuild on the motor with some 2.02 360 heads and an airgap intake and cam, i can also get a blow through carb from a buddy for cheap. Not sure if it would be cheaper after buying the turbo and all the necessary accessories to get some decent power, or will it end up costing more than building a 400 horse 318?
 
Yes guys have pushed stock cast pistons over 20PSI. It is all in the tuning..... Lean it out or detonate it & it goes boom.
 
Interesting. I did not know so much psi could be put upong a cast piston! Obviously the same would go for a hyper piston.

Soun'ds like anti knock sensor's are needed as well.
 
I am planning to one day do a 318 with 360 heads all stock stuff not sure on a cam, megasquirt for fuel and spark control. Then throw as much boost as i can at it on pump gas. that is what I am hoping to do at least. Single turbo seems like it would be the most cost effective for a budget build, and would be twice as easy as routing all the twin turbo stuff.

Probably going to do it in stages, like first build the engine get it in the car and running on a carb, then get megasquirt working. then add the turbo.

should be a ton of fun if i ever get to do it.
 
I thought we were talking about throwing boost at a 318? Stock Longblock...to pop and try again?

I have no qualms about using CAST PISTONS.

If you base tune using a WIDE BAND o2 Sensor, and tune for slightly rich,..and never go LEAN...no detonation will happen, and cast pistons can live (to about 800hp).

Kinda funny though,..:banghead:..how I have worked for Cummins Engine INC for nearly 8 years,.....stood in on countless Dyno Sessions, changed turbocharger components out, retested, and tuned, and somehow I am not knowledgeable to give out Forced Induction Advice that anyone believes
IS CREDIBLE......

:wack:

I could embarass a street driven 572ci Hemi Owner with less than 1/4 of the displacement (given a budget equal to what would be necessary to build a 572 Hemi, I could build the whole car)....wish I was rich....because BOOST is THE replacement for Displacement.


Weaksauce.
 
I believe you prine! Your info is always bang on with what I have read in Corky Bell's book Maximum boost.I find most mopar guy's to be stuck in n/a mode,wont run NOS,turbo's etc..
 
Prine said:
I thought we were talking about throwing boost at a 318? Stock Longblock...to pop and try again?

I have no qualms about using CAST PISTONS.

If you base tune using a WIDE BAND o2 Sensor, and tune for slightly rich,..and never go LEAN...no detonation will happen, and cast pistons can live (to about 800hp).

Kinda funny though,..:banghead:..how I have worked for Cummins Engine INC for nearly 8 years,.....stood in on countless Dyno Sessions, changed turbocharger components out, retested, and tuned, and somehow I am not knowledgeable to give out Forced Induction Advice that anyone believes
IS CREDIBLE......

:wack:

I could embarass a street driven 572ci Hemi Owner with less than 1/4 of the displacement (given a budget equal to what would be necessary to build a 572 Hemi, I could build the whole car)....wish I was rich....because BOOST is THE replacement for Displacement.


Weaksauce.
Click to expand...

The guys that don't believe you have not done any research at all. Anyone who has spent some time on the subject would know what you are saying is true and correct. It is just out of the norm for most Naturally Aspirated guys to get a grip on.
 
Double your budget and you may be up and running in about a year.

NO such thing as a "Budget Turbo Build"! I know first hand! Barely helped being a "ebaywhore". LoL
 
have thought about a turbo build before, how much boost can you run in a street application with 91 octane for a 318 with iron heads?
 
Prine,

I was not discounting your assertion that the 'teen can handle it, I just was wondering who is running it currently and the boost levels that folks are running in what combos. It was just something that I was musing about since the 318 has such low compression to begin with.

While I know that the lowly 318 doesn't get a lot of love, I was thinking since they are out there to be had and people practically give them away, you can start there without having to upgrade internals and still be streetable and MUCH more respectable on pump gas.

I know that knock can kill pretty much anything with less boost in short order. So what I was thinking in terms of a "budget build" is using quality components and a good tune on a low mileage stock block. If it gives up, you then make the move to upgrade the internals. Two cracks at it on the same block...that was kind of what I was thinking.
 
5.3 Stock Junk Yard Motor. No Intercooler, EBAY GT45, Wired the Waste Gate Shut and Hit it with a 75 Shot all the way thru the run @22PSI. He ran 119 MPH in the 1/8 and a 6.05 time with the lil poke in the beginning.
I know these engines are aluminum with Cast Pistons. You get the Idea "Cast Pistons" This guy knows how to tune!

[ame="http://www.youtube.com/watch?v=wTV8QTIVYB0&feature=player_embedded"]michasmovie.wmv - YouTube[/ame]
 
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