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 Post subject: Rebuild questions
PostPosted: Wed Jun 09, 2010 10:26 am 
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First, let me introduce myself, as I have been following the board for some time and have made some posts. I live near Enderby in the North Okanagan and have a 1961 Amazon that had a B20 in it. You may be familiar with the tale of woe related to switched hoses on a remote oil filter resulting in an overheated engine. About all that is salvageable from that engine are oversize pistons, a "T" cam, dual springs, rods and lifters. The block would need a line bore and the head seems to have been pretty much shaved. I obtained another engine from Dale that will serve as the basis for a rebuild. The block and head are unmolested, although the cam and lifters are toast. I am going to get the cam bearings replaced, it looks, to my untrained eye, that the bores will just need a hone, the pistons a re-ring and it could go back together with a new cam. What cam?? I'm leaning towards a K or D cam. The K can run on regular springs and I have conflicting info on the D - B20 Paul suggests it needs dual springs, which I have but it means the head will need work. Where I want to end up is with a reliable engine with a little oomph to pull up the hills around here. I welcome any and all thoughts on a direction here.
Thanks.
Bill


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 Post subject: Re: Rebuild questions
PostPosted: Wed Jun 09, 2010 9:51 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
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Location: Lethbridge, AB
Hi Bill,

Have a look at my build thread...my little B20 can pull hills all day long and has enough grunt to scare you if you are a little timid. Dual valve springs are PN 625/626 from Isky (they do the push rods as well) any competent machine shop can cut the spring seats large enough for the springs. The exhaust and intake ports need to be cleaned up or all the cam etc is a waste of time. I'm still not sold on the big bore, unless you sonic check the bores. Get the flywheel on a diet - everything else is well covered.

That's just about it - keep the questions coming, it makes us all think.

Craig

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 Post subject: Re: Rebuild questions
PostPosted: Thu Jun 10, 2010 11:34 am 
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Thanks Craig. Yes I have reviewed your engine build thread many times over the past year or so, but I have missed is a succinct (concise) list of the parts and specs used. I'm Scot. So what I'm trying to figure out is what is reusable from what I have and what must be purchased. I have a set of dual springs from the first engine, the "T" cam (no intention of using), lifters for that cam that appear to be "like new", rods (similar), these rods and lifters total 10"3/8, and Mahle pistons(R401) marked 89.25,.015 and sp0,04 on the top, that appear "good". The "new" block looks good and may not need a rebore, but the pistons have vertical score marks on the skirts at 90 degrees to the pins, so maybe it will need a rebore. If it doesn't need a rebore then I would do a hone and put new pistons (std) and rings in. If it needs a rebore what about reusing the oversize pistons I have with new rings? Which cam K, D or other? Could I reuse the lifters and rods (the stock lifters and rods measured 10"5/16 and are definitely not reusable)? As for the head a "cleanup" port and polish is in order with a grind for the dual springs if reusable. Would the port and polish necessitate a "valve job" i.e. new valves, valve guides and grind? What about "sundries" at various times I have read that head bolts and main bearing bolts should not be reused, true? What about con rod bolts? Any other "not reusable" parts? Thanks for the thoughts, all are welcome. This is about learning, I'm not embarrassed about my naivety on this, so don't worry about insulting me by pointing out the obvious, that I've missed.
Thanks.
Bill


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 Post subject: Re: Rebuild questions
PostPosted: Fri Jun 11, 2010 7:28 am 
Haha, I just built a W24 Octo-Turbo, now what?!

Joined: Wed Dec 21, 2005 8:03 pm
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I'm not convinced the D or K cam needs double valve springs. Volvo never saw then need in the thousands of engines they built with each cam. I would go with the D cam but that's just my preference. I had one in the B20 in my 122 and it had plenty of zip. In fact, on the one trip that Craig's car and my car were actually both running, I was climbing hills in one gear lower than Craig on a fairly consistent basis. This, of course, before Craig dropped the built B20 in his car and was running the B18.

I may be wrong here but I believe Bill is trying to do this on somewhat of a limited budget. Not saying he doesn't have the money to spend, just saying he may not want to drop the load on this engine that Craig did on his...

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 Post subject: Re: Rebuild questions
PostPosted: Fri Jun 11, 2010 2:42 pm 
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Dale is correct. I don't mind spending the money where it's necessary. I'm OK with the "need" to do's but the "nice" to do's require prioritizing, because I have other competing addictions.
Thanks.
Bill


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 Post subject: Re: Rebuild questions
PostPosted: Thu Jun 17, 2010 9:17 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
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Location: Lethbridge, AB
I'm not around here much at the moment...but here are my futher thoughts. First, doing a rebuild on the cheap is possible only but power output goals are directly related to money spent (using an approximately exponential function) - getting that last 20 hp costs 100 times what the first 20 cost etc...if you're NA anyway.

Back to the topic. You need to measure everything - not kidding. There is no substitute (no "I know this guy that rubbed his finger nail on my cylinder walls and said I was OK with a quickie hone job" stuff). If you don't have the tools, any competant machine shop can do this for you.

I wouldn't used scuffed pistons and using used lifters on these engines is like saying that you'd like to do it again shortly as the lifters eat the cam (these engines are the basis for a number of valve train stress test measures) that is a big no, no. Lifters are cheap. You should have the block professionally cleaned as well (I usually do this myself because I'm cheap as well - but I always get them baked, then do the final clean).

It takes hours and hours of prep to do it right, but I'd think a reliable rebuild can be done for just north of $1000. Doing it with all new parts and careful measuring and attention to detail will set you back at least another $1500. Doing what I did will double that total (don't do this).

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 Post subject: Re: Rebuild questions
PostPosted: Thu Jun 17, 2010 10:52 am 
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Thanks Craig. I have located a retired Albertan machinist who was president of the local car club in the Shuswap here. He has done many rebuilds on older vehicles,(only works on old vehicles - many local prizewinners). He was independently recommended to me by three different people and has the machinery and the time. Because its his "retirement" he only takes on jobs that interest him and works at half the rate of the regular machine shops. He hasn't worked on a B20, but has in the past owned both a B16 and a B18. I have taken the torn down parts (Block, Head, Crank, Flywheel, pistons and lifters) to him and we did a cursory inspection. The Block is very clean (but will be cleaned). The bores are very good (very slight ridges) he thinks a hone may be all that is necessary, but is going to measure. The deck checked OK on a quickie run with the straight edge at a number of angles as did the head, but he will do a more detailed inspection before we make any decisions. He was impressed with how good a 37 year old engine is. The cam, lifters and rods with this engine are shot. Lifters I had from the previous engine are very good (very slightly worn) and he suggests they only need an easy resurface (I haven't made up my mind). The crank and bearings, by eye, seemed very good. He will measure the crank, but thinks a polish will be all that's required with new bearings. He will do a "clean-up" port and polish on the head (he commented that the casting seemed very clean to begin with) with an emphasis on opening the exhaust ports to the gasket. He will do a valve grind, check the guides and replace the seals, and resurface the valve train part that pushes the valve (name escapes me - old guys mind fart). He thought the pistons might be OK, but will measure and err on the side of caution, but a "re-ring" might be doable. With new cam bearings the consensus seems to be to put a D cam in with single springs. I'm resurfacing the flywheel - he cautioned against lightening it ("you'll sacrifice smoothness, and not gain much"). I'm still pondering new pistons, lifters and rods. I will be transferring steel cam gears and upgraded cam and rear seals from the old engine along with the oil pump, distributor, valve cover and oil pan. A question mark remains in my mind about reusing the head bolts, main journal bolts and con-rod bolts, some warn against this, but it seems to be routinely done. Comments and ideas from one and all are welcome as I learn and work my way through this. Thanks again Craig and Dale for your help and guidance.
Bill


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 Post subject: Re: Rebuild questions
PostPosted: Thu Jun 17, 2010 3:24 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
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Location: Lethbridge, AB
Lifters are about $7 a piece - no place to economize and light wear means they are tossed in the bin - NEVER reuse them (yes, I have strong opinions about lifters - old used ones make cam lobes flat). Pistons are more expensive and if the scuffing is just normal wear (a few thou is allowed - remember the way a piston is shaped - wider at the skirt than at the top) and not the result of it running out of oil or over-heating then a set of Deves rings is just the trick. I would tend to stay away from just honing if you can feel a ridge - how would you know that the hone (using a drill) is not just smoothing things out a little and leaving you with a tapered bore? Check the specs for taper, off the top of my head I think 3 thou is the limit (actually that sounds too big to me - check).

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 Post subject: Re: Rebuild questions
PostPosted: Fri Jun 18, 2010 9:11 pm 
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The OEM pushrods seem to have a questionable reputation. What about alternative suppliers for rods, lifters and pistons other than IPD.
Bill


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 Post subject: Re: Rebuild questions
PostPosted: Sun Jun 20, 2010 11:07 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Location: Lethbridge, AB
Isky sells these with Chevy 350 lifters. I dont recall the part numbers.

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 Post subject: Re: Rebuild questions
PostPosted: Sun Jun 20, 2010 4:21 pm 
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Are the "High performance" lifters IPD sells Isky Chev 350 Lifters? I think the rods and lifters with the original engine where an IPD kit. They sure look like the pictures on the website. If I replaced the lifters could I use the rods, if they aren't bent or worn?
Bill


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 Post subject: Re: Rebuild questions
PostPosted: Sun Jun 20, 2010 8:03 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Posts: 3131
Location: Lethbridge, AB
bones wrote:
Are the "High performance" lifters IPD sells Isky Chev 350 Lifters? I think the rods and lifters with the original engine where an IPD kit. They sure look like the pictures on the website. If I replaced the lifters could I use the rods, if they aren't bent or worn?
Bill


Yes, they are the same part. When I got mine from Vintage Performance, they were Sealed Power units with NAPA part numbers! The pushrods are reusable.

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 Post subject: Re: Rebuild questions
PostPosted: Fri Jun 25, 2010 10:32 am 
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Just talked to my machinist. After honing, the tapers measured between 1 and 1.5 thou. Piston clearances are all less than 3 thou, in spec. So it looks like a re-ring it is. The good part is I didn't have to ask him about this. He called me to let me know what he had found. The crank is going to be reground 1 thou under. I new exhaust valve and new guides throughout. Just waiting on parts now.
Bill


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 Post subject: Re: Rebuild questions
PostPosted: Fri Jun 25, 2010 10:42 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Just a quick confirmation on the clearance spec- I know on B21/3 and B230 engines the spec is in the 0.001-0.0015 range, I'm guessing the b18/20s are different? Forged pistons (that expand more) would lead to larger allowed clearances.

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 Post subject: Re: Rebuild questions
PostPosted: Sat Jun 26, 2010 1:19 pm 
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I don't have my book to double check. Left it with the machinist. I may be wrong on the clearances, but he assured me the pistons were within the required spec to reuse the stock pistons and that the pistons were not thrashed, just normal scuffing which wiped (polished?) off. I will double check when I pick up the pieces. I'm waiting on new parts now to begin reassembly (backordered Deves rings, 2 weeks). Thanks for your thoughts.
Bill


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