Stroker build guidance, please

[John H]

New to the forum but not FEs. That said, I’m 30 years out of date on what the hot setup is. Great website and I’ve already spent 20-30 hours of reading; truly fantastic information!

Goal: Hot street/cruise and some drag use in a 1966 Fairlanes GT. Goal of 600-650 HP driving a dual disc, TKX, and 3.91+/-.

I’ve had a 427MR staring at me on an engine stand for decades. That needs to change. It’s a loose 030 over (old school TRWs). I borrowed a friend’s sonic checker and measured the block at 1” and 4” down the bores and the thinnest thrust wall is 0.180” with most in the 220-240 range; it not a problem to take more measurements if there are know thin spots.

I’m astounded by all the new technology that is available and at affordable prices, compared to the old days. The TFS heads seem to be the current choice for hot street as does a hydraulic roller (spec TBD). A Scat 4.25 stroker seems like a no brainer but is there an advantage to a 4.125? H or I beam rods? Mahle pistons (my shop neighbor swears by them)? The TFS R-Series 2x4 tunnel wedge is a look I like but will it complement the above? I’ve had #40 flywheels in the past but now I see 25-28 steel ones are available which should be sufficient given the increased torque.

I understand the chassis will need work as well but am I on a reasonable path for the engine? All input appreciated.

[blykins]

No reason to bypass extra displacement in that application. Scat crank, Scat I beam rods, Mahle pistons, TFS heads, TFS intake, hydraulic roller.  You’ll meet your goal very easily.

Got all kinds of these combos in the dyno results section. 

[frnkeore]

I'm a bit suspicious of those sonic numbers. With a 4.26 bore, they don't leave any space, or they would interfere with the adjacent cylinders. It sounds like you might have had the wrong metal setting.

 

[John H]

Thanks for the input, guys!

I’ll mic a section of block and check it against sonic tool when I’m back in town.

[hbstang]

yes,stroker for sure,but use the best quality rods you can afford,not the cheap i beams lol.molnar or scat h beams will be good.there is a ton of good build info here as well as jays main page with dyno stuff.

[Joe-JDC]

A 468 cubic inch engine at 1.4 hp/ci will get you the 655hp level. A 482 cubic inch engine at 1.4 hp/ci will only be 675 hp.  That is only 20 hp difference and if you already have the 4.125" stroke crankshaft, I would go with the 468 build.  You will need close to 330-340cfm head flow and at least 370-380cfm intake manifold flow to reach your goal with either combination.  The TFS heads will need a bit of cleanup in the ports to reach 340cfm at anything over .600" lift, and the TFS TW intake flows 405cfm with a simple gasket match to the TFS heads.  BTDT.  Don't open up the TW any larger than the 1247 Fel Pro gasket size, or you will lose torque, even with those cubic inches.  This advice is for a street/strip build.  There is a lot more possible with more head flow and more compression.  The TFS heads can be cleaned up to flow 350+cfm and keep the velocity very high for racing purposes.  Joe-JDC

[blykins]

The Molnar rod would be a good upgrade but the Scat I beam is not a “cheap rod”.  I send them with all of my 445/462 kits as they are much lighter than the H beam.  I haven’t sold a Scat H beam rod in forever, I don’t think they really have a place these days. For the price, a Molnar rod is much lighter and close to the same money. 

600 hp with a 482 is pretty easy. 650 will take a few extra details.

[My427stang]

What Brent said, the SCAT I beam is a nice piece, of course Molnar is real nice too.

[fairlaniac]

I'm a bit suspicious of those sonic numbers. With a 4.26 bore, they don't leave any space, or they would interfere with the adjacent cylinders. It sounds like you might have had the wrong metal setting.

 

Me too? 4.63 bore spacing minus 4.23 bore leave about .400 for two wall thicknesses and coolant flow. Two .200 walls are touching and no coolant flow? Am I wrong?

[John H]

The figures I provided were the thrust sides. The thickness between the bores was less. I’m out of town but when I return I will post the sonic figures. That’s assuming I don’t need to recheck after testing again a “standard” as previously stated.

Again, thanks for all the input!

[My427stang]

My technique is repeated "re-verification" on the china wall and top of cylinder between cylinders where I can measure near the deck while I go.  .

If all your thrust sides are where you think are, you are good, but I have not seen a lot of side oilers that thick.  If it is a center oiler with med riser heads, more likely they will be thick. 

Keep in mind, no need to go a fixed overbore, torque plate hone to make sure it's straight and buy a piston for the size you need.  I'd bet if the bore isn't bad it could be as little as .035 over.

Bringing the numbers you want is doable, go 4.25 arm and no power brakes, cam it healthy with compression to match and a ported single plane, it'll be a monster

Only downside is that if it is an early block, no hydraulic rollers or lifter oiling.  Not a show stopper but a big hyd roller is fun and easy.  Opinions vary, I am not a solid roller fan without pin oiling, so I would go big flat tappet.