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Im still getting used to my 85 Barth. I'm not super pleased with the 454 it has. It is leaking oil from the oil pan, and it doesn't do great on hills. And by that I mean, I just took it on a 60 mile round trip in WI and sometimes I had to floor it on hills just to keep it at 45mph on 55mphs roads.
We would love to at least take this coach to CO or NM but I doubt it would make it , especially since I was planning on a toad.
Has anyone had a good result getting a crate motor or rebuilt engine put in? I feel like this engine is gimped from emission restrictions.
Mid 80's was a bad time for the 454 in trucks. By 1980 all cars had converted to fuel injection but GM was not forced to change trucks over and so the 454s had low compression, retarded timing, carburetors, and smog air pumps. Not until the 90's did they finally upgrade to fuel injection. (God forbid they make the best vehicle they can rather than make money selling outdated crap.)
The stock engine in my 86 Regal was rated at 230 or 240 hp. It had 8.0 to 1 compression ratio, a four barrel carb and two air pumps. It also leaked out the rear main seal. Headers but 2 into 1 exhaust. About 6.5 mpg.
I replaced the crankshaft and seal, removed the pumps, and advanced the timing. Better but still weak...
I installed a TBI fuel injection system and dual exhaust pipes and it was a bit better. Around 7 mpg
I decided that I would replace the engine. In order to bring the old 86 engine up to power, it would need to be bored, higher compression pistons installed, and cam modified for roller followers. It would still have 2 bolt mains and 2 piece split main rear seal.
The 454HO engine has forged crankshaft, pistons, rods, and pistons. Large valves, roller camshaft, 4 bolt mains, one piece rear seal, high rise manifold and 8.75 to 1 compression. Rated at 438 hp! It ran like a scalded dog. The 33 tag axle Regal coach could do 90 mph!
Unfortunately, GM still sells crap. The front seal leaked a qt in 700 miles. The valves were not installed properly, I had three burned INTAKE valves after 12,00 miles. Also, the power band was really too high and it lugged down between 2nd and 3rd shift. I replaced the front seal and got the valves ground. I installed adjustable ball stud rocker arms to get the valves set right. I swapped the cam for a 502HT cam with about 20 degrees less duraton and 10 degrees less overlap.
The final result was pretty good. Now around 375-400 hp, good powerband and 7.5-8 mpg. Coach will do 80 easily and pulls well on hills. Uses almost no oil. Sold it to Alan from Austin, he seems happy with the engine.
There are threads here for the crankshaft job, 454HO swap and fuel injection installation.
I would say the 454HO is a good collection of parts but they are assembled in Mexico and build quality is variable. If I bought another one I would tear it down, check all specs and put it together right before I installed it.
Some other site members have had Jasper engines installed with good results.
Good luck with your project.
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 300 hp
Search Steve VW on here. He has documented information on how to replace the 454 engine.
Depending on what you want to pay but take a look at the 454 HO here, https://www.1800runsnew.com/new-base-engines/
These are marinized engines which mostly means they have brass replacing steel in gaskets etc. It also means they have been designed to run uphill 100% of the time, not too many long downhill or level stretches when you are pushing water instead of air. The price versus Goodwrench is close and I have had problems, some time ago but never the less problems with Jasper.
Money can't buy poverty
Nice link Tim. Would the marine engines require extra cooling capacity if installed in a Barth?
Formally known as "Humbojb"
My 85 Regal had a 454 with Thorley headers and a guadrajet. I drove it from Arizona when I bought it and got over 10 mph. Once home, took off the air injection junk, a/c compressor, added a Gear Vendors 6-speed, rebuilt the carb, all new fuel lines, and it still got about 10 and never met a hill it couldn't cross over easily. Roger Pence drove it across the Rockies to Washington--no problems. If you look at my old posts, you'll see some interesting information on special plugs and wires that I had. One caveat--I drove about 60, no more. Kept it at about 2500/2600 RPMs. It drove like a Cadillac on a 192" wheelbase. Who knows, someday I might have the option to buy it back.
It occurred to me that you may want to give the old 454 a chance, it may respond to some treatment.
If the oil leak is not too excessive and a deal breaker, you could check a few things.
Emissions constraints resulted in low compresion, lean mixtures, retarded timing, exhaust pumps, etc.
You may also have issues with fuel starvation, esp at full throttle.
I would do a compression check. If the cylinders are similar and not too low, move on. Otherwise you need rings or valve job.
Check timing. The OEM setting was like 4 degrees BTDC. In addition, the vacuum advance was disabled until fully warmed and in 3rd gear.
Set the timing to about 10 degrees BTDC. If you put the timing light on cyl 5 you can use the timing marks down low on the driver side.
Find the vacuum line on the distributor. Follow it back to the port at the base of the carb. There are usually tees and valves along the way. Run a straight vacuum hose to the distributor from the Qjet.
Check for vacuum leaks. The only lines you really need are the vacuum advance, transmission vacuum modulator, and PCV valve. Check the vac line to the HVAC system. The HVAC is often a vacuum leak. For test purposes remove and plug other lines too.
Meanwhile the 454 likes its' fuel... The OEM fuel system was marginal for full throttle. From engine pumps, to electric frame pumps, to intank pumps with recirculation, GM tried everything and never got it all right. Starvation and vapor lock plagued them. So... be sure all your fuel lines are clear, be sure your pump(s) are working, be extra sure all filters are clear. There may be in tank sock filters. Be sure to check the TINY(!) filter in the Qjet right where the fuel line meets the carb.
Check that Qjet secondaries are not stuck. You should be able to feel and hear them open at high throttle. Use more gas but better for hlls and passing.
Check air filter, and exhaust for restrictions, etc. Remove smog pumps and cap the plumbing. Headers help the 454 noticably. Be sure the exhaust riser valve is not stuck.
Assuming you have decent compression, proper timing, and good fuel delivery, you should then see about what you really have. The OEM 454 was only rated about 240 hp. Pitiful for the 454.
My 454 crate motor ran about 375-400. good luck
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 300 hp
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