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The 351c.net forum has a topic on this and I was going to post this info there, but I have been waiting for registration authentication, so I'll post it here before I forget all the details.

In episode 32 of RoadKill Garage, David Frieburger and Steve Dulcich build a 351 Cleveland Stroker.  Dulcich calls it a 406 at some point, but I think he meant 408.

They use aluminum Trick Flow 225 cc heads with 60cc combustion chambers.  The pistons are dished with valve reliefs to set the compression ratio, but I don't think they ever mention what that compression ratio is.  Freiburger confirmed on Instagram that the heads were straight out of the box and Dulcich did not port them.

The cam is a Comp Cams solid roller. 252/260 @ 0.050, 0.659 lift, 109 degree lsa.  He said the lobe numbers are 2513f and 2517f.

When installing they found that if they lined up the timing marks on the chain the cam would have been retarded.  They advanced it, but it is unclear how much.

The intake was the matching Trick Flow single plane.

They set the ring gap at "24-26"

They put it on the dyno at West Tech and unfortunately never show a graph.  When they first show the dyno screen it is already at over 6000 rpm.  At 6300 it shows about 630 hp and 520 ft lbs of torque.  It (torque) was falling, but hp was going up because it was falling slowly as rpms increased.  Peak torque was 550 and happened at 5400 rpm.  Peak hp was 658 at 7400 rpm.

I am considering copying this for my build, perhaps changing something (dual plane intake?) to move the torque lower and going with a hydraulic cam.  I would not want to spin it as fast as they did.  Changes might not be necessary if the torque curve is flat.  I will see if I can catch Freiburger on Instagram again and get him to share the entire graph.

My other direction would be Scott Cook heads and intake.  I like that he made these look like the stock stuff externally,  but I find the ability to drive 30 miles down I-75 and pick up a set of the Trick Flow heads (right now if I wanted) at Summit Racing and walk out of the door with them appealing compared to sourcing high dollar, heavy items from Australia.  The Trick Flows are based on a 2V arrangement (I think), but if they can make that much power, it's as much as I am looking to get.

Last edited by perryh
Original Post

 Common Chevrolet engine building takes an engine block and punches it out 0.030” but on our Cleveland cast iron blocks core shift makes this an unwise automatic approach. 

 My recent build was fine with just 10 over and that gave me 404ci.

20 over = 406ci

30 over = 408ci

 The less removed the more stout the block remains and should any mechanical issue damage a cylinder bore I will know there is still sufficient material to clean up a damaged bore rather than look for a new block  

Larry

I had a 393cuin with Comp Cams custom grind mechanical roller, grind 2314F/ 2318F, 250 - 258 @ 0.050, gross lift 0.640", lobe separation 110, cam in at 105.5. Used Scott Cook heads and dual plane intake, 640 hp @ 6,600 rpm, 537 lb-ft @ 5,800 rpm. This was also with Pantera Pat Mical headers. 11.2:1 compression ratio and ran on 93 octane. I idled it at ~ 850 rpm with 10 - 12 of vacuum, I was happy with the brakes. Up to you but I would not use a mechanical roller on the street, I broke a PAC conical valve spring with its no longer attached valve and later wiped a Manley Enduramax roller follower. It was good while it lasted, 21mpg on a run with FI and was fun.

Seems my engine output was slightly down in comparison with a smaller engine, smaller cam and lower rpm. Dyno headers gained ~34 hp over stock GTS headers on one run but I am not sure there was a good comparison run between Pat Micals, dyno and the GTS headers. My heads also had the incorrect exhaust valves which Scott said was bad. 

Waiting for a Tim Meyer aluminium block and using Scott's recommended roller hydraulic cam and use the correct valves. That one day will be dyno'd.

Good luck with your engine choice, there are many possibilities..

Last edited by bdud

Trick flow 195
20 over
10.4 static...normal European petrol (94 Euro),
Ross custom pistons (20 over)
10 deg advance
dual air gap Edelbrock MODIFIED as Trick flow intake is higher so need to modify
Crane cam think 5900 max (nerver really get there), ok idle, need to check serial number)

tremendous power

Last edited by matg

Trick flow intake ports per spec are a bit higher..(need to figure out how much).
I DID NOT do anything on the heads..as more precious..(smile). I modified the Edelbrock intake, is a bit tricky but via a tube cam could be done.

Modification just by fileing the upper portion of intake ports.  It is mainly on the top side as Heads are a bit up and intake hence too low/missmatch..The rest I did by playing with the gasket thickness. I did the gasked from scratch by special gasket paper..they come in different thicknesses.

 (I have digi cam pictures but hard to understand without lots of explain.)

(also you need to "Flatten" the carb side of intake by milling to make it "Flat" as original has an angle..then it fits the deck lit etc..). You Still need to modify the engine cover/the mesch metal thing..

 

 

Last edited by matg

FWIW, I agree with Larry. We both know a POCA member that had a stock Cleveland bored 0.040"-over, and a year later, the rings were still not seated. Due to 10:1 compression and thin walls, there was always blow-by from flexing cylinder walls. Please do not scrap more increasingly rare 351-C blocks by boring without first sonic checking cylinder walls! The 351-C is NOT a 350 Chevy!

Note also that in N. Nevada in the past year, we have had two separate examples of semi-pro built 427 stroker 351-Cs  that incessantly burned oil. With a 4" crank and stock height block, the wrist pin is forced to go thru the oil ring grooves, and both builders did NOT use a ring support rail (or the alternative- piston pin plugs). Without support, three piece oil rings will bend down at the big pin-hole from compression pressure on both sides, and open direct paths for cylinder wall oil leakage.

The result was a decent running engine that burned a quart of oil per 100 miles. After I found the ring support rails missing on one engine, the second owner pulled his engine and found the same thing (different shops did the work). Rebuilds with proper parts resulted in far more power, better gas mileage and oil use of a qt/2500 miles for both. Both owners are very pleased with their big engines correctly fixed by shops familiar with 351-C engines. I can't stress this enough- even if 351-Cs are from the '70s, they are NOT simple engines!

If your stroker burns lots of oil, look for that necessary oil ring support rail at the bottom of the piston ring oil grooves- they're really necessary for a 351-C with any crank over about 3.75" stroke!

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