Here's My Engine Plan. Comments

[Bill D]

Here\'s My Engine Plan. Comments

As I grow close to ordering my kit, I have spent the last few days laying out the engine build. Here is what I've come up with and would like to hear from those that have been down this path before.

Ford Racing aluminum block, 8.20 deck
Scat 3.25 stroker crank, 5.400 rods and 10:1 forged pistons
AFR 185 heads (2.02 intake, 1.60 exh)
Crane Cams hydraulic roller (.595/.595 lift, 236/248º dur @ .050 lift)
Electromotive direct fire distributorless ignition system
48 IDA Webre carbs
3-stage dry sump oiling system (mfr TBD)

On the dry sump system, I'm not sure if there is sufficient room with the alternator and A/C compressor.

All feedback welcomed and appreciated.

Bill D
Los Angeles, CA

 

[Ron Earp]

Re: Here\'s My Engine Plan. Comments

Bill, what kit are you ordering?

Engine looks good, I assume you will be tracking the car extensively with the ally block and dry sump oiling system. You've got a lot of good tracks in the area and it'd be a blast.

Best,
Ron

 

[Bill D]

Re: Here\'s My Engine Plan. Comments

Thanks for the reply Ron. Yes, the car is going to be run and run hard. That's why I plan for the dry sump oiling. However, since I don't have the car yet, I don't know how much room is available. I have looked at dozens of pictures, but they just don't show conclusively there is room. The setup I plan on using mounts low on the right side. I guess the alternator would mount above the pump, and the A/C compressor on the other side of the engine. I plan on using a 3 gl tank mounted on the right side? I'm trying to minimize long runs of SSTL line if possible.

Bill

 

[Bill D]

Re: Here\'s My Engine Plan. Comments

Ron

I am still trying to decide which kit. They're all so nice.

BD

 

[Mark Worthington]

Re: Here\'s My Engine Plan. Comments

Wow...sounds awesome. My comments:

1) Check out the Dart aluminum block as well as the Ford (FRPP). I understand that the Dart requires less machining and may be a better choice, and less expensive after macine shop charges are factored in.

2) An aluminum-block, dry-sumped engine with Webers screams out for a roller cam designed to make peak HP at about 7,000 rpm.

3) I think you could easily run another half point of compression and still stick with pump gas - even the crap they sell in California. Aluminum heads and a light car let you run a lot of compresison.

4) Read Lynn's post on blueprinting AFR heads. If you're stuck on AFRs, toss the upper valve train and find a meticulous machinist, otherwise consider the Edelbrock Vic Juniors.

 

[Bill D]

Re: Here\'s My Engine Plan. Comments

Thanks Mark

I have also looked at the Brodix heads but I don't know much about them.

As for the cam, do you think a solid roller would be better? I thought of using a hydraulic roller so I don't have to R&R the valve covers.

 

[Ron Earp]

Re: Here\'s My Engine Plan. Comments

Vic Jrs have issues too - all mass produced heads do when comparing to specs like Lynn and othersr are doing. Personally, no offense to anyone, I've run lots of out of the box heads to serious RPM with no trouble so I sort of feel like straining at 0.010" of the roller off center of the valve stem could best be compensated for by lots of other things such as drivers ed, etc. But, perfect it perfect and I undersrand what some are gunning for.

Bill, if you are going to build a dry sump motor, with aluminum block and all the goodies, by all means use a solid roller cam. It looks like you are going down the road of fairly serious competition motor so you might as well not cripple it to a street rev limit with a hydro cam. Now is the time to be realistic with your needs.

I plan to track the s*&$ out of the turnkey I get but I'm still using a wet sump with windage and baffles as well as a hydro roller - but I know it'll last. When it goes I might go full bore like you but I don't think my driving would be up to it at this time.

R

 

[Hershal Byrd]

Re: Here\'s My Engine Plan. Comments

Bill,
Your head choice is probably the best out there right now. I would stick with those.

Hersh /ubbthreads/images/graemlins/smile.gif

 

Re: Here\'s My Engine Plan. Comments

I think you should look at the Dart block more carefully. I think I heard that it's very hard to get the FRPP aluminum block.

You should go with the biggest bore possible. The Dart's sleves can be bored to 4.165" I think, so don't settle for less than 4.125" bore. It's free cubes. It also unshrouds the valves for better flow. 2.08" intake valves are no problem with a 4.125" bore.

Some research has shown me that it's almost impossible to have too much cylinder head flow. As long as you have good velocity, more flow is better, you just have to make sure that your cam is appropriate for the engine. I would use the 205's as a minimum. They have the raised exhaust port for much better exhaust flow.

The cam is critical to performance. You probably won't find the optimum cam off the shelf. The cam also has a great effect on detonation resistance. The less duration you have, the less static compression your engine should have. Advancing and retarding the cam will move your torque curve around and can also change the detonation resistance.

You should either use simulation software to choose a cam, or leave it up to a cam guru like Ed Curtis.

 

[Bill D]

Re: Here\'s My Engine Plan. Comments

Thanks Built2rev

Just for kicks, I looked at Comp Cams' mechanical roller. I found a cam that is close, although I will talk to them and have a custom grind made to match everything else. The Comp Cams grind # is XR292R. Specs are as follows with 1.6 rockers:

.621/.627 lift, 254/260 dur @ .050, with a 110 lobe separation. Good to 8000 RPM.

As for heads, I heard that smaller intake runners provide more velocity. Combined with the Webers, I would think this would be a benefit. This is theory of couse.

I will definitely look at the Dart block and the larger AFR heads. As for the heads, they will be disassembled and fully polished and pocket ported to improve flow.

One thing I'm concerned about is exceeding the Webers' capabilities with too much cam and heads.

Bill

Bill

 

[David Briggs]

Re: Here\'s My Engine Plan. Comments

Hi, I don't think AFR 185's will match up well with your cam and displacement. 205 better, a little less cam lift, 48IDFs and MSD digital(8 individual coils, fully programmable) otherwise sounds swell!

 

[Bill D]

Re: Here\'s My Engine Plan. Comments

561234-

I think I prefer the 4.000 aluminum block over the 4.125. Reason being pistons for the larger bore block are not readily available. Plus I'm trying to avoid going over the top.

So, let's take another shot and see what the opinions are:

DART aluminum block with 4.000 bore and 8.200 deck
Scat forged steel crank with 3.25 stroke and 4.030 bore (I believe that yields 331 ci), 5.400 I-beam rods with 7/16 ARP bolts, and 11.5:1 compression pistons (pushing it I know)
Mechanical roller cam around, say .600 lift with 250/260º dur
AFR 205 heads pocket ported and fully polished
Dry sump oiling system with 3-stage pump
Jessel or Crane Cams pedestal roller rockers
Electromotive direct fire system w/coil packs
Weber 48 IDF (easier to tune I hear) induction
Head and main studs instead of bolts

Comments please.

My goal is to build a stout motor with around 525-550 Hp that can sustain hi revs all day long. Not a drag race motor, but an engine that will live on the road race circuit.


Bill

 

[Tim Kay]

Re: Here\'s My Engine Plan. Comments

Hey 561234,

Any way of contacting you? I wanted to ask you a question.

 

[David Briggs]

Re: Here\'s My Engine Plan. Comments

Hi, my E-mail is [email protected]

 

[David Briggs]

Re: Here\'s My Engine Plan. Comments

This looks like a better combination.

 

Re: Here\'s My Engine Plan. Comments

So, your buying an aluminum block and you don't want to spend $900-1000 for a set of custom pistons? That does not make sense.

A big bore does not have any drawbacks. Since you are moving more air per stroke, that will increase the velocity of the air in your intake. That will let you run bigger volume ports without hurting your torque. You also can use bigger valves so that the ports can flow even more. It's a win-win situation.

I imagine that this engine will cost more than $8,000. If so, the $400 extra for custom pistons will give you a six percent increase in displacement and power for a 5% increase in cost. The big bore will also shift your power band down so that you won't have to turn as many rpm, so your engine will be less stressed and your parts will last longer.

I'm planning a similar engine with an iron block. I'll show you the simulations that I have run. Expect Email in a few days.

 

[Bill D]

Re: Here\'s My Engine Plan. Comments

Thanks Built2rev

I have looked into the custom pistons further and they are not as expensive as I first imagined. The plan is to go with a 4.125 bore and 3.250 stroke. That yields 347.5 ci. Crane Cams can grind a custom mechanical roller to match whatever heads I choose. Speaking of heads, I have looked at the DART CNC'd heads with 225 cfm intakes, 62cc chambers, and 2.08/1.60 valves. What is your opinion on these?

Thanks
Bill

 

Re: Here\'s My Engine Plan. Comments

Bill:

As long as you’re going to spend the money on aluminum block, you might consider the block with the 8.7 inch deck height. That would allow you to run a 6 inch rod, for a much better rod/stroke ratio. If you intend to run 8000 rpm, you might need a better rod ratio.
If it is of any help, I built a 302 with a very long rod (5.665). We have run the engine on the dyno, and the long rod did not hurt the power at any point. My engine produced 453 hp @ 6800 rpm. My engine builder said it was not experiencing any valve float, and he could of twisted it higher. Since I don’t intend to compete with the car, he didn’t see any reason to do so. However, the power had not yet peaked.
Good luck in your project

 

Re: Here\'s My Engine Plan. Comments

If you go for a 8.7" deck, I would not use a rod longer than 5.7". That would have a very good rod ratio, and the compression height of the pistons would be tall enough that there won't be any crowding of the ring package.

On the other hand, the 8.2" deck big bore 347 has a rod ratio almost as good as a stock 302 which has no problem reving high. And the big bore 347 will have no problem making 500+ hp below 7,000 rpm.

I'm lucky, I can't use a tall deck block, so I know I have to go 8.2". It's a whole can of worms that I can avoid.

 

[Bill D]

Re: Here\'s My Engine Plan. Comments

Is there a problem with using the taller 8.7 block and fitting an intake manifold? Seems that raising the deck .500 would require a special manifold to fit.

Bill