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Re: #2 compression = 60
Posted: Sat Feb 04, 2017 1:27 am
by ObnoxiousBlue
The BD heads are AMC's. They're great castings but everything else about them is absolute junk. There are. Certainly enough folks who install them as is and run them as long as able. But the valves, seats, essentially everything but the casting itself are crap.
I have a set of Len Hoffman's heads on the way. Same cast head but gutted and upgraded everything else.
Problem with most originals you might come across is they've been rebuilt and rebuilt and rebuilt, or have cracks and aren't rebuildable.
You can absolutely run the AMCs out of the box, but don't expect them to last forever.
Re: #2 compression = 60
Posted: Mon Feb 06, 2017 8:03 pm
by Markus
ugh, yeah. Hmmm.
Re: #2 compression = 60
Posted: Thu Feb 09, 2017 8:31 am
by Markus
Do I need to hone these new BD cylinders?
or if I see cross hatching its ok?
Re: #2 compression = 60
Posted: Fri Feb 10, 2017 8:39 am
by Raj
Markus wrote:Do I need to hone these new BD cylinders?
or if I see cross hatching its ok?
If they are 'new' I would think they would not require to be honed. Agree that cross hatch is a good sign that they are good to go.
Re: #2 compression = 60
Posted: Mon Feb 13, 2017 8:51 am
by Markus
Right, in fact they come with the pistons installed in the cyl. If I can assume the ring gaps were positioned properly I could install them on my engine and no need to buy or borrow a ring compressor.
Re: #2 compression = 60
Posted: Mon Feb 13, 2017 11:39 am
by Raj
Markus wrote:Right, in fact they come with the pistons installed in the cyl. If I can assume the ring gaps were positioned properly I could install them on my engine and no need to buy or borrow a ring compressor.
Id recommend cleaning the inside of the clys to remove any coating used during storage/ shipping. Also you may want to confirm the ring gaps are positioned around the cly correctly and rings are not put in upside down ( if applicable) Also, given the cost of the ring compressor, its small insurance to ensure all is good to go.
Re: #2 compression = 60
Posted: Wed Feb 15, 2017 12:12 pm
by B MAN
Markus wrote:Right, in fact they come with the pistons installed in the cyl. If I can assume the ring gaps were positioned properly I could install them on my engine and no need to buy or borrow a ring compressor.
gotta scrub them down & position them yourself
i live in hempstead and have a spring compressor u can borrow
Re: #2 compression = 60
Posted: Tue Feb 21, 2017 3:24 pm
by Markus
Cool, thanks for the advice. Pep boys might have something in the loaner section.
Re: #2 compression = 60
Posted: Wed Feb 22, 2017 9:48 am
by Tom
Re: #2 compression = 60
Posted: Tue May 16, 2017 9:01 am
by Markus
Had a bit of a snafu with some spark plug threads but the heads are on. Currently putting tins and fan hub, alternator back on (wish I had made a note of the order in which all this stuff needs to go back on).
Is there a trusted break in oil? Or will any old 10w40 do?
First oil change at 100 miles, 500 miles? Both?
Re: #2 compression = 60
Posted: Tue May 16, 2017 10:39 am
by Raj
Markus wrote:
First oil change at 100 miles, 500 miles? Both?
I dont think you can ever change your oil too frequently; the down side comes to the cost benefit of 'cleaner oil' as the added time and expense of the material. On a new build that I put some money into... id opt for the more frequent interval erring on the side of caution.
Im excited for the results!
Re: #2 compression = 60
Posted: Tue May 16, 2017 10:57 am
by Glenn
I use Brad Penn breakin oil and then switch to Brad Penn 10W-30 after.
First run for 15 minutes varying the speed between 2000-2500rpm. After, dump the oil and let cool. When cold, adjust the valves and refill with fresh breakin oil.
Second run for 15 minutes varying the speed between 2000-2500rpm. After, dump the oil and let cool. When cold, adjust the valves and refill with fresh 10W-30.
Drive for 100 miles making sure to vary the speed and that the engine us "under load" to breakin the rings. After 100 miles, dump the oil, let cool and adjust the valves.
At 500 miles, dump the oil, let cool and adjust the valves.
At 1000 miles repeat.
At 3000 miles do regular oil and valve adjustments every 3000.
Oil is cheap, so better to do it more often than less.
Re: #2 compression = 60
Posted: Tue May 16, 2017 12:33 pm
by Markus
wow thats a pretty intricate break in but I'm up for it. I'll assume a few minutes at start up to just let it idle and warm up.
Mike, you going to run it like this?
Re: #2 compression = 60
Posted: Tue May 16, 2017 3:52 pm
by Glenn
Markus wrote:I'll assume a few minutes at start up to just let it idle and warm up.
Nope, get it running and let it rip.
Have a timing light connected so you can set the timing as it's breaking it.
If you let it idle at startup you'll have low oil pressure and could damage the cam/lifters.
Re: #2 compression = 60
Posted: Tue May 16, 2017 3:54 pm
by BusBq Bill
Don't let it idle during initial break in!
Re: #2 compression = 60
Posted: Wed May 17, 2017 8:28 am
by Raj
Glenn wrote:
If you let it idle at startup you'll have low oil pressure and could damage the cam/lifters.
interesting.... Part of me would think that the higher revs right off the bat wouldnt be the best idea. Makes sense re: oil pressure though.
Re: #2 compression = 60
Posted: Wed May 17, 2017 8:46 am
by Markus
gotchya. and i can at least static time it beforehand, then dial it while running.
Re: #2 compression = 60
Posted: Wed May 17, 2017 12:08 pm
by Tom
He has hydro's so I don't think he needs to do the frequent valve adjustments you mention, maybe after 5k if he replaced them which I doubt.
Re: #2 compression = 60
Posted: Thu May 18, 2017 7:46 am
by Markus
the engine is actually an earlier 2.0. they are confirmed solid lifters.
Re: #2 compression = 60
Posted: Thu May 18, 2017 8:24 am
by SUMTHING
78' was the first year of hydro's (why I put one in my 73')
Re: #2 compression = 60
Posted: Thu May 18, 2017 2:18 pm
by Tom
Markus wrote:the engine is actually an earlier 2.0. they are confirmed solid lifters.
Why would I assume he has the original engine ?

Re: #2 compression = 60
Posted: Mon Aug 27, 2018 8:28 am
by Markus
Ok almost 2 years since I pulled the engine, about time for an update. I had some issues getting everything done and engine back in (oh and wife and I also had a son so cut me some slack). Heres what happened:
wouldnt start, sanded the rotor a bit and started right up. I'll order new parts for a full tune up.
ran rough and LOUD. Not like metal parts banging together loud but Harley with straight pipes loud. I'll lift it up after Labor Day and check out the headers.
timed it static and then with the gun and started Glenns procedure getting both 15 minute break in runs done over the last 2 days. My neighbors now hate me. Was a bit difficult to time since it won't hold idle. The oil didnt seem to have metal bits in it which is good i guess.
also tried to re use valve cover gaskets and one leaks. I have no luck trying to re use those...
I hope the loudness and rough running is an exhaust issue. thoughts and comments welcome.
Re: #2 compression = 60
Posted: Mon Aug 27, 2018 8:31 am
by Markus
btw i used the old headers with the new heads and fresh copper gaskets.
Re: #2 compression = 60
Posted: Mon Aug 27, 2018 10:53 am
by Tom
Do you have heater boxes or have you eliminated them ?
Re: #2 compression = 60
Posted: Mon Aug 27, 2018 1:54 pm
by Markus
Yes, i kept the old exhaust heater boxes and the round cylinder muffler that i think is called eliminator? Put together with new flange gaskets and copper gunk paste. I wasnt this loud before the top end job.