Any guesses?

[mike_starling]

Talked to the engine builder yesterday. I think we had a miscommunication of intent.

Engine specs:

351 SVO 4 bolt main block
Lunati untwisted billet crank w Cleveland journals; internally balanced
Oliver billet rods
Wiseco forged pistons
T&D Machine roller bearing rockers on tubes
Cam Motion cam [email protected] And .540" Lift w solid lifters
Pro Action heads done right
CR 9.75:1
Edelbrock Performer Airgap intake (says works as well as the Victor Jr.) with single 4 barrel. Max rpm at 7200 or so.

Is a semi-dry sump set up. Transaxle will be G50/52 with spray bars and the gawd-awful Sachs clutch and pressure plate.

The miscommunication was that I suggested I wanted to limit the torgue to 500 lb-ft and he thought I wanted to limit HP somewhat.

He's low estimating at 450 hp/425 torque. He's always a bit low.

Any guesses as to what this combination will actually make?

Next question is the obvious one ... If it makes only his estimate on the dyno, this would be a right sporty combination. A change to the cam and lifters could brighten it into the hairy range. The tranny be happy with >500 hp and about 500 lb-ft of torque?

Thanks,

 

[Ron Earp]

Never heard much about those heads. They look very similar to a World Products casting, very similar. I think if it was my dime I'd go a small bit more cash and do some AFRs.

 

[Kevin M]

Mike,

Are you staying with a 3.50” stroke (351) or going longer? (3.75”, 3.85”, 4.00”)

The SVO is not a bad block but I would suggest looking at the DART block in either Iron or Aluminum. Consider the 4.125” Bore option.

I am not familiar with Pro Action. Are they a porting company? Are the heads actually a Yates head, SC-1, etc? (I noticed that you are using T&D shaft rockers, which suggests a Yates type head). If not, take a good look at a properly ported Yates SC-1 head. Check http://www.chapmanracingheads.com/p_home.asp , they are very good people.

If the Yates are a little too much for you, then I would agree with Ron, get AFR 205s.

Unless those heads are Iron (Seems unlikely) the compression is low. For aluminum heads with that kind of cam 10.5 would be much better.

The RPM Airgap is a great manifold up to about 6,200 rpm. If you are going to 7,000 get a Victor Jr. (This will also help with keeping the torque down at lower RPMs). (If those are Yates heads they take a special manifold and neither the RPM or Vic. Jr. will fit _ Edelbrock makes several Yates manifolds).

Last: If I were spending that kind of money on those bottom end components, I would look very seriously at a Mechanical Roller Cam. (The Yates heads require a mechanical roller). Look at something like Comp Cams street roller series, they are not as radical as a race cam, use lighter spring pressures and the extra lift will give you much better power with a good set of heads.

Use Crower roller lifters with the “High Pressure Pin Oiling” option. (Yes it is fine to mix brands with the Comp Cam in this case). There is a problem with pin oiling in the lifters on engines that see a lot of low RPM usage (Street) and these lifters solve it.

You will probably need a cam in the 250 deg @ .050 range, or a little higher. Lift should be over .600. Don’t go crazy on lift, stay away from anything over .650. You want a cam where the spring pressures are well below 200 lbs on the seat. Racing cams with 225 to 250 lb springs will break valvetrain components on a regular basis. Call the tech people at Comp or Crower, tell them this is a street engine and you don’t want anything that is not reliable.

If you decide not to use Yates heads, use Comp Cams Hi-Tech Stainless Steel Rocker arms.

If built properly with the Yates or AFR heads, that engine should make over 550 hp at 7,000 rpm. (The Yates will obviously make more than the AFRs).

As for the transaxle, you might want to check with Ultima Cars in England. http://www.ultimasports.co.uk/ They use that transaxle, and a lot of their owner run very high HP engines, so they should be able to tell you how it holds up.

Kevin

 

[Lynn Larsen]

Mike,

The engine I am building is a short stroke 347ci (3.25 stroke X 4.125 bore.) I am using AFR 205s w/~10.5:1CR. Keep in mind that this is an EFI engine and that I am using the big Roush intake. The target is for the engine to make ~500-550HP and be able to turn up to 7500RPM. The cam that was recommended to me for this set up was a duration of 232-238 @.050 range, on a 110-112 center with .600” lift.

I also gave the same admonition that I wanted to be gentle to the tranny, relatively speaking anyway

Lynn
Keep the greasy side down.

 

isnt the pro action a very nice australian made head

 

[mike_starling]

I really don't know where the heads are made. They are certainly Finished in the US. They are not widely known for sure.

Some comparable (I think) flow data on CNC ported versions of the heads:

.500 lift .550 lift
AFR 205 intake 305 314
exhaust 223 231


Pro Action intake 325 337
exhaust 241 250


Their experience has been that the Performer Airgap and the Victor Jr intakes perform about the same on the dyno. The rpm range was not specified on this little tid bit of information, but after 30 years of knowing me, the builder knows that I like to run'm up.

 

[Kevin M]

Mike,

That’s a significant difference in flow on those heads. Are those numbers for the stock heads or after special porting? Do you know what the intake port volume is? If it is close to the AFRs (IE 205 to 215cc) definitely go with the Pro Action.

I would love to hear your final numbers when you get that thing built and have it dynoed.

By the way, do you have a web link for Pro Action? These sound like they justify further investigation.

Kevin

 

[Brian Kissel]

Hello Kevin !!!

Pro Action can be found here ::
Pro Action

There is a lot of information on their site. Enjoy!
Regards Brian

 

[flatchat(Chris)]

Yeah thats the ones, Ive just fitted a pair of f1208000180 with the 58cc chamber, should be 10.5:1 compression ratio and they are IRON--there's enough weight in them that we don't need bolts to hold 'em on ,but they look real good staight out of the box.The ports and flow characteristics are better than the heavily worked over 1970's ones that I have disgarded. With fingers crossed should be all fired up this w,end then I'm off to Germany for a few days and back in time for the first race of the season /ubbthreads/images/graemlins/cool.gif

DRB#17
Fresh mill

 

[flatchat(Chris)]

They're made in New Zealand (of all places?)and come in fleecey lined boxes. Probably a good thing as some of worlds best drivers come from their ,You know -Chris Amon,McLaren etc
Cheers Chris /ubbthreads/images/graemlins/cool.gif

 

[mike_starling]

Engine has finally gotten to the dyno ... initial results are nudging 500 hp with a flat torque curve ... 445 lb-ft peak with 400 still at 6000 rpm.

May have more complete numbers tomorrow, but it sounds like this one will work!

 

[John]

I'm running the 180cc "pro lightning" aluminum heads from that company on a 355 small block Chevy in my old Camaro. I'm extremely pleased with them. Great off-idle torque even with a somewhat big cam, but keeps pulling great up top.

John