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Engine blocks and strokers

 
Old 10-05-2005, 10:07 PM
  #16  
EB338
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Where is "Sterling" at on this one? I just found his website and what he did to his car, I am very interested to hear his input on all this. The block modifications he did are truly impressive!!
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Old 10-05-2005, 11:13 PM
  #17  
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Originally Posted by John Veninger
Oh so true.......
compared to a cheby crate motor for sure... granted, it's not super cheap or fast to do a HP 928 motor, but it's really not that bad compared to a complete OH at a dealer, and if it extends the life of the car another 10-15yrs, while giving it 30% more zip - it's kinda justifiable if you factor in the fact you don't have to go to 2 different parts stores (auto zone/928 intl) to get parts... compared to buying a new AM, Z06, or GT2, or 355, etc it's a bargain, and although it still won't have a cup holder - it's still pretty sexy in a nostalgic sort of way, IMHO.....

my old 85S became somewhat more of an effort/PITA when I swapped the heads, added the GT intake w/flappy and insisted on using GT OEM ECUs for flappy/knock control for an OEM look - and to keep tuning to a minimum (in review, an smt-6 might've been a bit cheaper/and more flexible for sure)... but now, it's just looks like a (yawn) clean fat and lazy 85S in SCCA sorta stock trim... so put your money down right here lads, nothing to fear w/that shiney new ricer/ferd/cheby... dundun-dundun-hehehe...

for an 87 up, it's a LOT easier - just a decent valve job, and a bottom end OH w/a few different parts, some gaskets and presto!! oops, no traction... well, there is the fuel reg, xpipe/whatever exhaust, minor oil control updates, tbelt, and GTS intake tubes that help a bit, and don't forget dealing w/the wife (my biggest challenge - but in some respects nothing new for me - or her, ha!!).... AND don't forget - you get a NEW motor that doesn't leak or seem scarey(well, except for the 1st 10 intial startups if you use cometics), sounds great, looks clean, and should be pretty darn reliable for quite some time... course you gotta eventually OH the int/brakes/trans/suspension too, but that's often already done along the way over the years anyway as stuff needs maintenance - so it's not all at once like the motor at least (unless you do it like brendan, on the multiyear plan ).... just my .0928 cents

IIRC, it was steve "pappy" pappin w/the intake spacers- but he was on a 5.0L S4 w/GT cams, xpipe, chip, and some clever fresh air intake mods - was a strong runner for what he'd done for sure/as lidar confirmed too IIRC IIRC, greg brown still has a set, and was considering them on my old gal, but it's so stupid strong/tractionless out of the hole already he decided against trying anything else - at least till I start whining about "needing" more power.....

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Old 10-06-2005, 10:14 AM
  #18  
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Im just thinking out loud here, but given the design of our blocks and the open access to the inside and outside of the cylinder bore, wouldn't it be theoretically possible to sleeve both the inside AND the OUTSIDE of the cylinder bore to increase strength and get us into the 106mm bore neighborhood? Possibly in conjunction with the partial water jacket block filler and installation of a deck plate like "Sterling" did on his 928sg engine?

I don't know what kind of issues we get into with thermal expansion sandwiching the aluminum between the two steel sleeves, but then would it be possible to omit the inner sleeve if we installed an outer? Or possibly to make some kind of forms to apply a thin layer of the block filler around the bores all the way up to add strength?

Admittedly this is quite a bit of tedious work and possibly would be better off cutting the bores out completely and installing complete wet sleeves, but it was just a thought I had that I figured I would bounce off you guys.
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Old 10-06-2005, 11:45 AM
  #19  
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Originally Posted by EB338
Or possibly to make some kind of forms to apply a thin layer of the block filler around the bores all the way up to add strength?
I've been thinking about this lately also. Maybe it could be possible to make mould, incert it into water area and then fill up it's surroundings with block filler. After filler is dry take out mould and block cylinders have thicker walls. Trouble is I don't know if block filler can stick to existing walls enough to stay on it with all the heat cycles etc. Have dead 951 block for experiments but haven't gotten that far yet.

Probably easier to buy support rings and mount them instead. Can't remember who makes those but there should be some pics in archives. Only problem with those are that material needs to be taken off from block to make cylinder towers perfectly round. This will eat up already very small margins. Especially if bore is increased also.
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Old 10-06-2005, 11:55 AM
  #20  
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I suppose another issue to address would be the application of torque plates when installing sleeves and boring cylinders. The parts all need to fit together with the block stressed in assembled condition. Applying torque to head bolts and main caps will twist the block material and distort the cylinders. Everything needs to be fit precisely under torque load. Custom fitting a round sleeve or a round piston to a hole that will end up oval when assembled wouldn't work very well. I know sleeving is done with regularity, I just don't fully understand how the two different materials live together when they absorb and react to heat at different rates, and react to fastener torque loads differently. The same would hold true for the filler I suppose, if it became hard then the block saw deformed around it. Apparently it can be done because it frequently is. Would the sleeve on the outside of the bore trap heat in the aluminum of the original bore and lead to problems?
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Old 10-06-2005, 12:38 PM
  #21  
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Hey Brendan,

Sorry, didn't catch the gist that you had a line on a set. (Didn't realize Heinrich had a set) Definitely not trying to scoop someone else's deal. I know we had swapped some emails about my set, in the past, just wanted to let you know that I've still got 'em.

Still waiting on the pistons. I'm told that the tolerances will end up at around 2 thousandths, but won't know until the pistons show up. They were ordered with the Pins raised 5 thou to help decompress things. Probably give them a little more time, and if they haven't produced them I'll pull the order and go the nikasil/JE route. Everytime I get tempted to do this though, I look at that Wisconsin 928 builder's site (he's using the same pistons) and think that the Mahle's are definitely worth the wait.

Head are getting worked on right now. The machinest just started porting the adapter plates for the individual throttle bodies. I got to see them yesterday, they are looking really good. He said he'll probably dowel pin them as well.

I'm in the market for cams and springs, and will probably go with a set from 928 Developments, as I don't see any other options out there for the A/T cars.
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Old 10-06-2005, 01:55 PM
  #22  
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hey adam, sounds like you're plugging along - those ITB's should rock!!! IIRC, the beef w/gt cams on an AT was low end losses - but on my old AT car, w/modified GT cams and stock springs, I can assure you there's no issue w/low end - in fact there's still too much, although it could be aggravated w/the increased stall on the converter a bit I suppose (2100rpm or so vs OEM 1600rpm)... might want to talk to mr ott about cams from other sources too, he's got some good insights.... devek's b1 set seems pretty nice too....

EB338/Errka - what the point of spending a major effort/$$ to keep the oem block for monster bores if you can just use a cheby or custom race block?? IIRC, custom racing blocks are lighter and way stronger than anything you can build out of leggos and a 928 block... not like you're going to use pcar parts inside, the OEM ECU, or much else on the outside anyway, and it does open up the door for lots of cool hot rod heads, roller cams, all the goodies one would expect on a major HP race motor, etc??? could always modify covers to say porchev, porsche, beast/whatever...
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Old 10-06-2005, 02:46 PM
  #23  
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Valve Springs - Mark A. posted to my thread about 32V sprinsg that he uses 12 dollar springs from a 944S2. He races on them and says he has had no issue, even with his cams (whatever they are). 12X32 = 384 dollars plus shipping for great springs that are already tried and true.

Threshie's springs are also an option, but I am unsure where they are from. I think they may be 968 springs for that car's higher redline.

Those Mahl pistons are nice. How much were they again?



Originally Posted by atb
Hey Brendan,

Sorry, didn't catch the gist that you had a line on a set. (Didn't realize Heinrich had a set) Definitely not trying to scoop someone else's deal. I know we had swapped some emails about my set, in the past, just wanted to let you know that I've still got 'em.

Still waiting on the pistons. I'm told that the tolerances will end up at around 2 thousandths, but won't know until the pistons show up. They were ordered with the Pins raised 5 thou to help decompress things. Probably give them a little more time, and if they haven't produced them I'll pull the order and go the nikasil/JE route. Everytime I get tempted to do this though, I look at that Wisconsin 928 builder's site (he's using the same pistons) and think that the Mahle's are definitely worth the wait.

Head are getting worked on right now. The machinest just started porting the adapter plates for the individual throttle bodies. I got to see them yesterday, they are looking really good. He said he'll probably dowel pin them as well.

I'm in the market for cams and springs, and will probably go with a set from 928 Developments, as I don't see any other options out there for the A/T cars.
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Old 10-06-2005, 04:03 PM
  #24  
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knowing my luck, somebody will announce it next week - just like the 85 cam thing... might have to get another 928 just to take advantage of all the neat stuff I could save money on....hehehe...
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Old 10-06-2005, 04:14 PM
  #25  
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Originally Posted by Sterling
what would be cool would be for somene to get darton or some company that makes those high end blocks to make a billet 928 block that is set up for stock heads, and larger bores.... can you say 108 mm? what about making the bores so large that they are siamesed like the 968 blocks....


Anything is possible sterling.
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Old 10-06-2005, 06:16 PM
  #26  
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Adam,
Might want to get soem references on cams first before you buy.

As far as I know, only two" real race" 928 engines have been built. Even mine is just a higher compression standard DEVEK stroker with 550 rwhp with intake and 500 witout intake. Even Dons at 575 with my intakes has mostly standard stroker guts.

Louis' engine will be the first 500 rwhp NA street engine ... using my long block technology and our intake system.

god luck!

Marc
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Old 10-06-2005, 06:21 PM
  #27  
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DEVEK B1 Cams - $1600 per set/exchange Group buy 5 unit price - around $1200 per set/exchange.

Used in the highest hp 928 engines ....


Marc
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Old 10-06-2005, 08:26 PM
  #28  
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928SS
EB338/Errka - what the point of spending a major effort/$$ to keep the oem block for monster bores if you can just use a cheby or custom race block?? IIRC, custom racing blocks are lighter and way stronger than anything you can build out of leggos and a 928 block... not like you're going to use pcar parts inside, the OEM ECU, or much else on the outside anyway, and it does open up the door for lots of cool hot rod heads, roller cams, all the goodies one would expect on a major HP race motor, etc??? could always modify covers to say porchev, porsche, beast/whatever...


Ive built quite a fev Chevrolets and more oldsmobiles than i care to think about. I know it would be relatively easy to drop a small block Chevrolet in my 928's and then build the engine with off the shelf parts glaore. Im just not too keen on doing that to my Porsches. I want to build the 928 engines for the sake of building these already neatengines into something more
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Old 10-06-2005, 08:40 PM
  #29  
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Its fun to build them. Its fun to serach out the right parts etc. Usually.
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Old 10-06-2005, 08:40 PM
  #30  
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Ugh, clicked the wrong button before I was done there, sorry everyone.

I guess to sum it up in response to 928SS post. I've built Chevys, now I want to build Porsche. (here is where I will probably start something I didn't intend to) The current Corvette is in some ways GM finally catching on to what Porsche did in our cars 27 years ago. I don't see why GM putting a 427 (7.0) in front of what is essentially a modernized clone of the 928 layout cant be bested by the same displacement in our 928's.

I'm not trying to over simplify what GM has done, or diminish the impressive machine the new Corvette is, I'm just I suppose seeing it as evolution from where our cars started, and a clear benchmark of what our cars could be if given all the advances and advantages the Corvette now has. Now I'm just trying to figure out how to do it!!
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