Prepare yourself for a few questions concerning the possibility of cranking a 170 up to 8 grand. There's a guy over on the .com board asking about doing something like that. He sounds like he's seriously considering it, but needs some good advise about what might be needed to accomplish it.

Roger

GTS225@aol.com

Ready and willing, I could only get 7500 out of my stroked 170. (209) The key is lots of cam and a good bottom end.
DD
(I hope my friend does not mind me using his computer!)

He's talking about a twin turbo setup, but right now they are arguing over the best way to cut out the alternator. Later! Dennis

slantzilla@excite.com

hmmm... the famous Doug Dutra. I wasn't actually going to go as far as to contact you but since someone has already started talking about me here I might as well get started. I've been getting mostly negative criticism since I started this idea so maybe you can help point me in the right direction. I would like to tap some of the potential of a 170 over 7k. Has anyone tried? What would you envision for something like this? I've started a discussion over on slantsix.com under the title "spin faster?" if you would like to see where I'm comming from.

Thanx in advance for any insight...


jeomomma93@hotmail.com

It is not that hard to get a 170 to spin over 7000 RPM, trouble is that using a 170 leaves a lot of cubic inches "on the table" and it is hard to make that up with more RPMs alone.

If you need to fit into a 3.0 liter class or just want to be different by having a high strung engine "tone", the 170 is a good choice. Pete McNickels, Wilford Day and yours truely have all run high RPM 170s

Remember that high RPMs are hard on parts and once you get enough air to flow, you will find a weak link, it will most likly be the factory con rods or a piston skirt. You are also going to need a lot of rear end gearing, I run 5.38 and really could use a 5.57 Are you thinking auto trans or some kind of manual shift trans? (like a light weight 5 speed)

OK, I will "cut to the chase", here is a combo:
You are going to need a few 170s as cores so you can select the best block and parts. (sonic check the blocks and closely inspect / sort the con rods) ARP con rod bolts, main studs & head studs will be money well spent.

Spend some time taking all the rough edges & "ugly balance bumps" off the crank and con rods, this cuts down on windage and lightens things up, both are good for a high reving engine. Get a high quality engine re-balance job. You will need an aftermarket vibration damper like a Fisher Damper.

Pistons should be custom made forgings with a thick top section to allow real deep valve notches but the piston also needs to be as light as possible. Static compression should be in the 12 - 13 to 1 area to off-set the big cam. This is the hardest part of this combo because the 170 is a "zero deck height" engine. It is hard to get valve clearance for the real big cam needed to support the high RPM air flow. I use a roller cam to help reduce this problem. (rollers can run steeper ramps to get the valve to full lift faster)

The head is the basic pockit port / oversize valve deal. A windage tray and crank scraper are a must. Try not to run any accessories off the crank, find some other way to keep the coolent moving and the battery charged.

Spend time opening-up all the oil passageways and port the crap out of the oil pump, this engine will need to flow some oil. (see the block prep article) Set the clearances loose on the bearings and piston fit.

One unexpected PIA problem I found with a high whinder was that all the bolts would always seem to come loose, the flexplate to converter and to the crank were the big trouble bolts to keep retightening. Lock tight and / or safety wire helps.

The intake will need big & short runners, the Clifford 4 bbl or better yet, the side draft Webber set-up will do the job.

That all I can think of, let us know if you go for it.
DD

Wow.... Thanx. That is a bit much to swallow right now but it defifitely got me someplace. I'm glad I'm not the first to try this. My transmission will be an auto with full manual valve body and a real high stall. I wasn't sure how big the rear was gonna have to be but now i have an idea. I guess I'll have to dig up an 8.75. I'm not quite sure that 12.5:1 compression is what I need as I was thinking about forced induction... maybe I'll have to rethink that idea. I really enjoyed that block prep article BTW. Everything else looks great but I'm still pretty concerned with water pump cavitation. The last thing I wanna do is get that thing spun up and lose water. Maybe a larger radiator and an underdrive pulley? or electric pump? I'm looking into aluminum rods and a roller valve train right now... There arn't many options here. I guess I'll need to add a nice deep sump in that oil pan regardless of how I set up the guts. Right now though I guess the best starting point is collecting blocks, strippin 'em down, and hauling them over to the lacal machine shop till I find 1 or 2 good ones. I have 2 170's now but I'm pretty sure one of them is bad.

Thanx for your advice!!!

jeomomma93@hotmail.com