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5 minute(s) of a 64 minute read
4-21-2013
The early idea was to get something dummied and take out a small amount once the math's are done. Just something to check over. The pistons also come in dished or machine the 8 shape in to the flat top if there is just a small amount to come out, or????
Try one of the beggars and get something made once all sussed out.
I'm sorry I don't know what the rod dimensions are, but I'll find out. There could just be something in the program which might match.
So 94 is about the magic bore! I'll also check for you regarding the Saab bits. Plenty in Aus.
This might be worth a look through.
http://www.performanceenginecomponents.com/Products/products.asp?type=dept&DepartmentID=719&MID=
While I'm here, does anyone have ideas for this multi spoke wheel? I think this style painted or polished, looks the business for a 505. We don't have many options, I know but, if any one can recommend something close to this , or where to look, would be great.
I noticed a nice genuine 308 wheel is close and a 17" rim.
5-22-2013
Not a lot of progress these last 2 weeks, although proudly I have proven my initial, safe, ignition timing graph, theory for air fuel tuning, works very well indeed.
The V8's ACL pistons really look the part in the over sized bore. We need to find a solution for the press fit gudgeon into the conrod though. The old pin was 23mm and the new is 22mm. There isn't a lot of meat in the rod to bore it for a full floater pin so we're thinking of using a reducer bush. That's 0.5mm wall thickness so we'll need to get the material compatibility right. I'm thinking of using a seal face repair sleeve but I guess we could just buy the material and machine it up on the lathe. The only problem with that is the lathe is still in the box!
So little time for things that really matter!
Number one son has turned 21 today too.
5-23-2013
This is the gently bored and honed, std. block with 0.030" Ford 250 piston. From memory a 0.010" cut to std.
Bean should be impressed with the squishy quenchy bowl!
Piston should sit 0.001 to 0.0015" above deck. This is prelim fitting. This gives us at least the minimum quench requirement clearance of 0.040", in the head gasket thickness. So, for best safe practice in this street/track engine from here I measure piston rock at TDC and then calculate rod stretch and bearing clearance etc for a very close indicator of just how close the piston could get to the head.
The big issue is with this very tight clearance is how far open the Inlet and Exhaust valves are at TDC.
and how close (0.040" min.) they can get to the piston at TDC.
I'm thinking metal shim style head gaskets to trim the squish to a minimum but have yet to research composite stuff. Some I know are near 0.050" so no good there.
Moving forward, slowly.
I've used ACl pistons in a lot of successful builds one of them 25 years ago when I was just out of my time and the boss and I built a sweet Holden engine with an incredible amount of torque for such a simple engine with not a lot of modifying. It is still running beautifully today, 6 cyl Triple carbs 13:1 Bathurst spec head. on 100 race fuel. It is a sleeper street car. The head has been changed twice as better ones pass through my friends ancient garage and into his hands. The pistons and bore are worn a little but sweet FA.
The Ford pistons are made here by ACL and just came up as being very close, once I got th' syferin' dun. It started with a challenge. Why hasn't any found a better piston combo for the s##t with no real quench, being fitted to rebuilt Rover engines? It turns out there is a Holden piston that fits the 3.5 as well. That has been done before.
ACL do a lot of race pistons and rings. And their listings are available easily! We have 6 cyl Ford stuff that has used the same piston for decades and has been turboed, all that so many types of pin height and bowls. The last decade has given a 4 l turbo multi valve var. cam timing, engine that just blows the V8 for torque and power. I reckon Ford pistons from ACL will do! I'm using Hastings rings though as the Old Ring Gap theory made me buy fileable rings.