BIG 351 stroker question

[fordracer]

I want to build a 408 and I have a couple of questions.

1) How far up the piston does the pin go ? I am trying to avoid the pin going into the oil ring.

2) What length rods are y'all using with a 408 ?

[PSB]

I got a 408W kit from Scat. The pistons were from Probe Industries, and the wrist pin does not intrude into the oil rings. The rods that came with the kit were Chevy 350 6.2".

If you haven't decieded where to buy your parts from yet, I highly recommend, Brian Adams (scatstroker@aol.com ), a Scat wholesaler. He was great to deal with and gave me a good deal on a balanced kit.

Pete

[wilf leek]

My 408 uses the Eagle forged crank and 6.2" H beam rods. Piston pin sits below the oil ring, using KB hyper pistons (can't remember the part no, sorry).

I avoided the 427 stroker precisely because on that set up, the piston pin is in there amongst those oil control rings, and the rod ration is marginal.

HTH

[Mr.Fixit]

It depends on your deck height, which is determined by what year the block was cast, how much it has been decked, and how much needs to be machined off this time to clean it up. Get the wrist in as close to but not yet into the oil control ring. Get the longest con rod you can fit into your combo. Getting a generic kit you may end up with the pistons coming out of the bores a little bit.

[sharpel]

Please forgive my ignorance, I have been considering going with a stroked 351W, possibly even the 427. What is the problem with the piston pin being up into the oil ring? Other than a potential for oil consumption are these issues significant enough to where you should stay away from these motors? Do these problems still exist with the 418 stroker? I drove an SPF with a 418 stroker built by Dean’s folks at HOC and it was awesome! Ever since then I have been thinking about getting a 418 or 427 since I thought they would be similar. If these engines all have the same piston pin placement problem am I better off building a stout 408 or 383? Can anyone enlighten me on this?

Thanks,
Mel

[Mr.Fixit]

Dean's 418's have the piston pin just below the oil control ring. It does not invade the ring land, but just barely.

[Andy Dunn]

here are a few 408 stroker links. Most seem to run 6.2" rods, but I see some use a 6" and others a 6.25".

http://www.speedomotive.com/ford_351...8w_stroker.htm

http://www.flatlanderracing.com/stroker351w408.html

http://www.coasthigh.com/Kits/kits_street_fighter.htm

http://www.hawaiiracing.com/sbford_408stroker_1b.html

http://www.hawaiiracing.com/sbford_408stroker_2b.html

http://www.dssracing.com/408%20stroker%20kit.htm

[750hp]

Originally posted by sharpel
What is the problem with the piston pin being up into the oil ring? Other than a potential for oil consumption are these issues significant enough to where you should stay away from these motors

Mel - my engine builder was more concerned with getting the best rod length/stroke ratio, more than hitting the oil ring. As such we went with a 3.9" stroke, 6.25" rod length. This gives 398 cubes @ 4.030 bore.

My only concern was whether the oil consumption would be SO BAD that the amount of oil entering the combustion are would be sufficient to increase the chance of detonation. I was told that this wasn't a worry.

For what it's worth, my motor just spent THREE WEEKS on an engine dyno. I haven't even checked the dyno log, but suffice to say we really gave it a hard time and probably did 80 power runs, aong with numerous lower rpm full load pulls. In that time, it didn't use a single drop of oil....

[sharpel]

I was talking to Coast High Perf. and they were saying that they use a 6.125 rod for their 351W 427 stroker, which keeps the piston pin out of the oil ring. What is the impact of using a shorter rod? Some of the previous posts mentioned that you want the longest rod possible? Is that true, and if so why? Appreciate the insight.

Thanks,
Mel

[Mr.Fixit]

A longer rod put a lower side load on the cylinder wall, but more importantly, it keeeps the piston at TDC longer so more cylinder pressure builds before the piston moves down.