We have an 85 Barth with a 454 Chevy engine that has over 100,000 miles on it. We are considering replacing the motor with a Chevy 502 510hp but I have not seen or heard of any body using this motor in a motor home.

Is there anybody out there that can shed some light on this and if it is a good or bod move.

I would recommend the ht502, pn 88890534 (google this number)

Here is one link:

http://www.gmpartsdepot.com/store/product1.aspx?UserID=...D=466&Category_ID=64


It has the torque peak where you want it.

As you go up in horsepower with the 502, the torque peak goes up, too. It becomes a race engine that requires revs to produce power and torque. The heavier the vehicle the lower you want your torque peak to be.

I put an ht502 in my 84 30t. Love it.

I have a 624 hp 502 in my boat, but it would be a pig in my MH.

Question for Bill H: I was reading the description of the HT502 crate engine. It was for pre smog vehicles only. How do you get your motorhome to pass the smog test every other year here in sunny California?

And now you know why I drive 1975 and older vehicles.

No smog check, well for the moment anyway.

However it should be noted that the smog stuff is external to the engine, the only issue I can think of with presmog engines is that they are more efficient and may have a compression ratio that is too high.

Timothy

quote:

Originally posted by JEFFREY HARMAN:
Question for Bill H: I was reading the description of the HT502 crate engine. It was for pre smog vehicles only. How do you get your motorhome to pass the smog test every other year here in sunny California?

Jeffrey, I have all the stock smog stuff installed. I use Thorleys and an MSD 6A, which gives cleaner burning due to the multiple sparks at low rpm. Before a smog check I run a tank of Red Line fuel system cleaner through it. I cannot recommend this product too highly. It even made my genset start and run better. Heck, my dog even minds me better.

I also change oil and filters, get it really warm and run it dry before a smog check. Then I pour in a couple gallons of alcohol and drive to the test guy. I run a lot more advance at idle, too. It passes every other year.

I still use the AC plugs in it, but my Jag /Chevy swap requires Bosch Platinum plugs to pass, so the new Barth plugs will be Bosch platinums.

Timothy, I have seen non-smog engines pass smog with a camshaft change. I had a previous Jag/Chevy and used a Crane cam to pass smog. They recommended one of theirs with less overlap. Performance seemed unaffected. I don't think Compression in and of itself is an issue because the 95 LT-1 in my Jag has 10.4:1 stock CR.