5.0 HO swap vs. conversion

Topic: 5.0 HO swap vs. conversion (Read 4179 times) previous topic - next topic

5.0 HO swap vs. conversion

Reply #15 – October 19, 2006, 07:43:13 PM

Thats cool, I'm doing an HO conversion...someday (when/if the Chevelle ever gets finished.....) but I'm very limited on funds...and I doubt my mom would be happy with me having more that 225hp (I'm surprised she doesnt have a prob with the stock HO). I was able to get all the parts for an HO conversion for around $250 total on eBay. As for exhaust, that upgrade will be coming very soon (if not before) the HO conversion.

And yeah, the extra money for the GT40 heads would be worth it. As for any potential problems, I'm not sure.

5.0 HO swap vs. conversion

Reply #16 – October 19, 2006, 08:37:52 PM

i doubt the heads will give you trouble, as specially with the stocker HO intake. hey, if it realy gives you trouble than you still can convert to MAF

5.0 HO swap vs. conversion

Reply #17 – October 20, 2006, 01:43:49 PM

Heads won't be an issue. The issue with speed density as has been stated before is that speed density likes a good amount of vacuum for a nice idle. It runs like poo-poo with aggresive cams with smaller lobe separation angles.

Speed Density likes vacuum to run properly. A good rule of thumb is that you can run speed density on a cam with a lobe separartion angle of 114 or more. Some cams with 112 LSA will work, some won't. Once you start getting real aggressive with the cams you must either go mass air or get a stand alone computer setup. I've included a list of speed density friendly cams as per 50tech.com. To run some of them will require a little tweaking with an adjustable fule pressure regulator and/or bigger injectors (there was one guy on that site supposedly running 36 pound injectors on a stock speed density computer with a rather aggressive head/cam/intake combo). The second pic is a fuel injector chart to show how different injectors flow at different pressures and the max supported horsepower level are.

5.0 HO swap vs. conversion

Reply #18 – October 21, 2006, 10:20:11 AM

Quote from: shame302;108404

it should go alright. keep in mind that likely that engine is going to come with hyperjunk pistionas`

Which are fine unless you want to use supercharger or nitrous... Even then a small amount of boost won't hurt anything... Hell Ronnie(chrome302jr) has sprayed a 125hp shot on his and it's doing fine..

My 428 Cobra Jet has cast pistons, that are not even as good as the hypeteruric(shiznit I can't spell it), 38 years later they have yet to be pulled out of the block...

For you guys converting, I'd give serious consideration to keeping the E6 heads. They actually give a little better low end torque and with all the other components changed to HO, you'll be at approx 205HP. Going this route eleminates the valve to piston issues, and you have basically the '86 HO version(actually the 86 didn't have a HO upper and used a smaller 58mm T-body).

But before any engine mods are made(or at the same time)convert to a good true dual exaust system. A good 2 1/2 system on a '86 HO will give 225hp easy(course a E7 head version will give closer to 245hp). The E7 figure is from MM&FF in a head test article. The stock HO produced 20 more HP on the dyno(using a free flowing exaust system), than it was rated.

5.0 HO swap vs. conversion

Reply #19 – October 21, 2006, 05:54:57 PM

I've got an '86 H.O,ported E-7 heads,BBk shorties,2 1/2 inch duals,off road x-pipe,Explorer intake,a/c and smog delete.I have NO idea on the horsepower.I'd like to know,especially ith the ported E-7 heads.Perhaps if I ever find a dyno,I'll check it out.I do know,it has great torque,and runs awesome.

5.0 HO swap vs. conversion

Reply #20 – October 22, 2006, 03:46:04 PM

So as the car sits right now it is going to get the HO dropped in instead of doing the conversion on the SO in it. Like I said before the car already has a pretty good flowing custom bent 2.25 dual system with stock Stang shorties and the HO upper and TB. I also have a 3.73 traction-lok so the car will move good. I know when it's done I'd be happy to get to 60 in under 7 seconds and run the quarter somewhere in the 14-14.9 second range (if i ever take it to the track). I'm thinking that's possible with the stock HO with out iron GT-40 heads. I just have to figure out if I want to spend the extra $150 on GT-40 heads.

Oh and TurboCoupe50 thanks for the advice on the conversion. If the engine had less than 125,000 on it I would probably be doing the conversion. I just have a feeling that if I did the conversion that the high milage rings or bearings might let go and i'd have to rebuild the short block anyway.

5.0 HO swap vs. conversion

Reply #21 – October 22, 2006, 04:03:04 PM

t-jet no problem, probably the best route... But I have a freind with a '88 Sport that has 340,xxx miles(yes three hundred-forty-thousand), heads never off(yea it's real tired)... It's now parked due to the AOD tranny finally expiring... I have a chance to buy it, but other than a decent body it's about ready for everything..

BTW here's a shot of the odometer in Feb '04 with 322k mi

http://members.pen 15s.net/mr428/wayne322K.JPG

5.0 HO swap vs. conversion

Reply #22 – October 22, 2006, 04:13:14 PM

Quote

340,xxx miles(yes three hundred-forty-thousand), heads never off(yea it's real tired)...

Holy :eek: . I guess 5.0s are really durable.

Based on your experience TurboCoupe50 the stock 5.0 HO will probably do what I want correct? The iron GT-40 heads would probably make the car just a smidge (ie .3) seconds quicker.

5.0 HO swap vs. conversion

Reply #23 – October 22, 2006, 04:16:24 PM

The Vic' has about 273,2xx miles on her 5.0

5.0 HO swap vs. conversion

Reply #24 – October 22, 2006, 04:20:21 PM

Yea with 3.73s and a 2400 converter a stock HO should get you into the 14s. But a buck and a half(additional) for the GT40s is a screaming deal... .3 is definatly an inprovement that can be felt... If you could make a comparison before buying, you'd be off that $150 in a hurry...

my advice... GET THE HEADS as well...

5.0 HO swap vs. conversion

Reply #25 – October 23, 2006, 12:00:42 AM

Thanks for the input guys. I'm going to go with the GT-40 headed engine. I found out that I can get it for $2,050 if I give the guy the engine that's in my T-bird now as a core. So I get $200 off. So for $2,050 I get a 5.0 HO with the stock roller cam, GT-40 heads, 1.7 roller rockers, oil pump and pick up, oil pan, front cover and water pump, and valve covers. Plus it comes with a 1 year 12,000 mile warranty. I like this deal. The guy has been in business for over 30 years and he has a good reputation with a lot of the car clubs in the area. I can't wait for March now so I can get this engine:cool:

5.0 HO swap vs. conversion

Reply #26 – October 23, 2006, 09:38:41 AM

All those miles and it looks like his f&cking gas guage still works.....

5.0 HO swap vs. conversion

Reply #27 – October 23, 2006, 01:26:43 PM

Quote from: CougarSE;109660

All those miles and it looks like his f&cking gas guage still works.....

As well as the others too, he's been in the dash and repl the voltage reg a couple years before the pic was taken... Car was cold(Feb) not started in a few days when I took the pict... I was holding the idle up, as it wasn't sure it wanted to keep running on its own...

http://members.pen 15s.net/mr428/wayne322K.JPG

5.0 HO swap vs. conversion

Reply #28 – October 24, 2006, 08:31:04 AM

Quote

I was holding the idle up, as it wasn't sure it wanted to keep running on its own...

With that many miles on it, I bet it was pretty sure it didn't want to run.

5.0 HO swap vs. conversion

Reply #29 – October 29, 2006, 09:25:06 PM

So one more quick question. Has anyone used a 5.0 HO speed density computer from a Mark VII with no ill effects? Every time I go to the wreaker I usually see 1-3 Mark VIIs there but no 5.0 Stangs. I know I'd be limited to 110 mph because of the speed limiter but I doubt I'd be driving that fast on public roads anyway. I just want to make sure my cruise control and other systems will work with no problems.