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454 HO engine swap
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Official Barth Junkie
Supporting Member of Barthmobile.com 1/24
Picture of Steve VW
posted
Hi, my name is Steve and I'm a Barth junkie...

So why would I take out a 454 that is running well and replace it with a new one? hmm

The OEM engine is running well with the new crankshaft and bearings. 40-60 psi oil pressure, good compression, uses 1 qt in 12-1500 miles. 110k total miles.

Problem is, I have over 25,000 miles in the last 3 years. In another few years the engine will be ready for rebuild. Question is, will I still be able to do it by then?

Meanwhile, the old 454 is only rated for 240hp. Low 7.9 to 1 compression limits power for hills and trailers.

Even if I did rebuild the old engine (I could) it would need pistons and boring, valve job, etc. It would still have 2 bolt mains and old style split rear main seal...

Meanwhile, I am working on wheel wells, getting ready to paint (someday) I also plan to replace windshields before I paint. While the windshields are out is a perfect time to change engines...

If I got a new crate motor… (GM part #12568774) I could drop it right back in as soon as the old one is out, not weeks later after machine shop, etc..
It would have all forged parts, 8.75 to 1 compression, 4 bolt mains, one piece seal, roller cam, 425 hp with 500 lb/ft torque! confusion

So, what would you do?





(At least this way I'll have a good engine left to revive one of Mary Ray's fleet.)

My name is Steve, I'm a Barth junkie. head bang

to be continued...


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
 
Posts: 5166 | Location: Kalkaska, MI | Member Since: 02-04-2011Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 1/12
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OK Stevey Baby Go for it. Cant wait for the pictures.............................


Former owner of "THE TOY"
1988 Barth Regal SE 33' Tag
1992 Barth Breakaway 32'
2005 Coachmen Mirada 32' DS

 
Posts: 592 | Location: North Fort Myers, Florida, USA | Member Since: 11-20-2004Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 2/16
Captain Doom
Picture of Rusty
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quote:
So, what would you do?


Seek counseling.


Rusty


MilSpec AMG 6.5L TD 230HP; built-to-order by Peninsular Engines:  Hi-pop injectors, gear-driven camshaft, non-waste-gated, high-output turbo, 18:1 pistons.  Fuel economy increased by 15-20%, power, WOW!"StaRV II"

'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP

Nelson and Chester, not-spoiled Golden Retrievers

Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering.
- Arthur C. Clarke

It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields
 
Posts: 7734 | Location: Brooker, FL, USA | Member Since: 09-08-2005Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 2/16
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I can't thank my fellow Barther's Smiler enough for all the gifts that I have received. Each one is a treasured gift that they could have sold or traded and they chose to give these items to me. That is true love!!!!!


Mary

Don't mess with us old folks, we don't get old by being stupid!
1968 Barth trailer, 1975 Barth Motorhome and 1985 Barth Motorhome

 
Posts: 1603 | Location: Obion, TN/Memphis, TN | Member Since: 11-23-2004Reply With QuoteReport This Post
First Month Member
Supporting Member of Barthmobile.com 11/13
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quote:
Originally posted by Steve VW:

It would have all forged parts, 8.75 to 1 compression, 4 bolt mains, one piece seal, roller cam, 425 hp with 500 lb/ft torque! confusion

So, what would you do?



My name is Steve, I'm a Barth junkie. head bang


The HT502 has a more usable ports, cam and power band for a heavy motor home. The 454HO would benefit from a Gear Vendors to get the most out of its power band.


.

84 30T PeeThirty-Something, 502 powered
 
Posts: 6169 | Location: AZ Central Highlands | Member Since: 01-09-2001Reply With QuoteReport This Post
Official Barth Junkie
Supporting Member of Barthmobile.com 1/24
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It will be interesting to compare power bands. Looking at the dyno curves there is not much difference from 2-3,000 rpm. The 502 has smaller valves and shorter duration cam, potentially better torque (not to mention more displacement.) I suspect the torque gain in the 502 has much to do with displacement.

The 454 comes complete with intake manifold and water pump It is several hundred cheaper, has square ports which match the square Thorley headers, rather than the later style oval ports on the 502.

The 454HO will put out more hp at 3000 rpm than the old motor did wide open. I suspect an overdrive will be desirable, I can't use one now with the lower output engine. Without the overdrive, the extra displacement on the 502 is potentially wasted with higher rpms, with it the 454 it should be adequate. We shall see!

454 dyno


502 dyno


Compare to stock 454:



9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
 
Posts: 5166 | Location: Kalkaska, MI | Member Since: 02-04-2011Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 8/11
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quote:
Hi, my name is Steve and I'm a Barth junkie...


The first stage of recovery is to admit you have a problem.

That is one heck of a beautiful motor you got sitting there Steve.

So have you established a time line for this project?
 
Posts: 259 | Location: SouthWest MI | Member Since: 08-12-2011Reply With QuoteReport This Post
Official Barth Junkie
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Thinking about mid summer for the transplant. I have pass side windshield, driver side is on order. After Milford and Canada fishing, I'll try to get to it then. mechanic


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
 
Posts: 5166 | Location: Kalkaska, MI | Member Since: 02-04-2011Reply With QuoteReport This Post
First Month Member
Supporting Member of Barthmobile.com 11/13
posted Hide Post
quote:
Originally posted by Steve VW:
It will be interesting to compare power bands. Looking at the dyno curves there is not much difference from 2-3,000 rpm. The 502 has smaller valves and shorter duration cam, potentially better torque (not to mention more displacement.) I suspect the torque gain in the 502 has much to do with displacement.


And a longer crank arm.

quote:
The 454 comes with intake manifold and water pump and is cheaper to boot, has square ports which match the square Thorley headers, rather than the later style oval ports on the 502.


Square and oval ports refer to the intake ports. The exhaust ports are pretty much the same. On stock Chevy heads, the square ports do not show an advantage until you get over 5000 RPM. My ski boat 502 has oval port aluminum Bowtie heads ported by AFR, and they produce more power than the square port heads they replaced. I can state this unequivocally, because a jet pump is like a water dyno. And the smaller, higher velocity ports provide much better part throttle running and fuel economy. It would barely idle with the square port heads and manifold. Of course, part of that was a rasty cam but I mention it just to illustrate the advantages of higher velocity intake ports. The higher velocity also fills the cylinder with a more turbulent mixture that allows about a half point more compression. However, playing with the squish can do that, as well.

quote:
Without the overdrive, the extra displacement on the 502 is potentially wasted with higher rpms


Yes. The ht502 is a hauler, not a racer. If I were building a heavy hot rod or (non-towing) pickup, I would not use it.

My opinions here are colored by the fact that we tow a heavy 4WD or boat up some steep grades, so your needs might be a little different.


.

84 30T PeeThirty-Something, 502 powered
 
Posts: 6169 | Location: AZ Central Highlands | Member Since: 01-09-2001Reply With QuoteReport This Post
Official Barth Junkie
Supporting Member of Barthmobile.com 1/24
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quote:
Originally posted by bill h:

And a longer crank arm.


??? The 454 and 502 have the same 4.00 stroke... Should be same crank arm? 502 has bigger bore...

Thanks for explaining the intake port shapes. That could have been an issue. Since the 502 does not come with an intake manifold, I'm not sure my OEM 1986 454 manifold would fit and have same port type.

My TBI fuel injection adapter plate is set up to bolt onto a carb type manifold anyway, so the new 454 manifold is good. I didn't want to have to buy/swap too many additional parts. (I obviously would have needed advice to buy the correct manifold.)


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
 
Posts: 5166 | Location: Kalkaska, MI | Member Since: 02-04-2011Reply With QuoteReport This Post
First Month Member
Supporting Member of Barthmobile.com 11/13
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quote:
Originally posted by Steve VW:
quote:
Originally posted by bill h:

And a longer crank arm.


??? The 454 and 502 have the same 4.00 stroke... Should be same crank arm? 502 has bigger bore...


OOPS! Shoulda verified before posting from memory.


.

84 30T PeeThirty-Something, 502 powered
 
Posts: 6169 | Location: AZ Central Highlands | Member Since: 01-09-2001Reply With QuoteReport This Post
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Awesome! Maybe add a blower in the fall? Big Grin
 
Posts: 249 | Location: Minnetonka, MN | Member Since: 01-30-2011Reply With QuoteReport This Post
Official Barth Junkie
Supporting Member of Barthmobile.com 1/24
Picture of Steve VW
posted Hide Post
quote:
Originally posted by Tonka:
Awesome! Maybe add a blower in the fall? Big Grin


You bet! Maybe some wheelie bars? confusion

Nothing like a few pictures of a hot rod motor to get this site going again! ROTFLMAO

Too bad it won't be ready for Milford. There's always next time! Thumbs Up


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
 
Posts: 5166 | Location: Kalkaska, MI | Member Since: 02-04-2011Reply With QuoteReport This Post
First Month Member
Supporting Member of Barthmobile.com 11/13
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quote:
Originally posted by Steve VW:


You bet! Maybe some wheelie bars? confusion



The 502 can twist the axle housing, so traction masters or a torque arm would be a good idea if you get into rough stuff offroading.

I was rocking to get out of a bad spot, and the housing rotated enough to cause an air bag to come apart.


.

84 30T PeeThirty-Something, 502 powered
 
Posts: 6169 | Location: AZ Central Highlands | Member Since: 01-09-2001Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 7/11
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Steve, I think it sounds like way too much work. mechanic

It would be much easier on you if you just shipped that crate down here to Crystal River Thumbs Up


Tom & Jillene

1988 Regal
28' Chevy 454
8805-3538-28C-B3
 
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