My Proposed Spec.

[Andy(UK)]

What do you guys think to my proposed 302 re build spec?

Ford 302 pre 1986 block (for UK SVA emissions).
TFS twisted wedge or Edelbrock performer rpm heads.
Edelbrock performer rpm intake.
Edelbrock 600 cfm manual carb.
Keith Black hypereutectic pistons. (Or similar to work with above heads.)
Eagle I-beam Rods (already got these).
Comp Cams 268H, lifters, timing chain set and push rods.
New cast crank (rated at 500hp. already got this)
Crane energizer or similar roller tip rockers.
Melling HV oil pump.

Does anyone have opinions on the twsited wedge heads? Are the performer rpms better or worse? And will I need to do any piston work or will they be OK with stock length rods with the twisted wedge heads?

Also is it easy to fit a windage tray to a block that normally didnt have one?

Thanks in advance.

Andy

[trularin]

Balance and blue print.

[Andy(UK)]

Thanks will definitely do that.

Has anyone else got any other thoughts? Especially with regard to performance & reliability?

Cheers

Andy

[Frank Gleason]

Andy,

An understanding of how you plan to use your Cobra would help.

fg

[wilf leek]

Andy - couple of questions:

1/ Why a 302? 351 might be a better place to start, more options to increase bhp in the future for pretty much the same base costs now. Remember that you WILL get used to whatever power you have and want more at some stage.

2/ Why a HV oil pump? Unless you are building to race bearing clearances (unlikely for a street car) a std vol + pressure oil pump will do perfectly well, and reduce the chances of distributor drive gear breakage.

As per the question already asked - what is the car for? What kind of rpm limit do you want? Some of your choices are already limiting your safe rpms to the 5500-6000 mark.
Do you intend ever to go the blower or NOS route?
Have you properly worked out your CR with the heads/pistons you propose?

Do you have desktop dyno? If so, you can plug in some options, not so much to get absolute power figures, but to see what shape of torque curve comes out, hence drivability.

HTH

[Andy(UK)]

Wilf, good lord, the very person whos passing from the UK clobra club has left a hole in the Ford knowledge base! I trust you are well?

The aim is to use the car as a daily drive/weekend use, maybe with the odd track day.

302 chosen:

a) I liked the sound of it.
b) only 5l not 5.8l
c) slightly shorter deck height = no bonnet clearance issues (may be putting a trick air intake arrangement in for a remote air filter. Also not so wide.
d) Most imporantly its Ford!
e) I scared myself in a Type R that weighs more and has less power/torque!!

Not intending to blow it or use NOS, rev limit not too high as you say 5500 to 6000 rpm. (will be limited by the MSD ignition to 6000) HV oil pump becasue Ive got a new one in a box upstairs!

Now decided on the Performer rpm heads not the TW's, aiming for 9.5:1 CR. Dyno2000 shows the setup I listed putting out 344BHP and 328 ft/llb torque. (at flywheel) peak power at 5500 rpm.

Im not after a screamer, or a stock motor. Something in between. Ive been told the 268H is a good cam with a slight lope and good top end. Again the dyno curve looks nicer than the rpm cam, not so much top end.

BTW Ive just purchased a brand new rpm intake on Ebay for $127.50, thats £50 cheaper than UK prices by the time youve added import and the dredded!

What do you/people think of Speed pro hypereutectic pistons? Are they any good and can Keith black Silv-o-lites work with press fit rods?

What do you think now? Any advice.

Cheers

Andy

[Tom Kirkham]

I am not a big fan of hypereutectic pistons. Since you have said that you will track the car I would reccomend forged pistons. I would also not skimp on the oil pan. I think you would be happier with a Holley carb.

[rdorman]

I recently had a engine builder of excellent reputation tell me that he does not like hypereutectic pistons. When asked why he reached under the bench and pulled up a zip-lock bag of small metal pieces. He said that this is why looking at the bag. He went on to say that if you experience detonation then this is what will happen. They appairently don't melt down or crack, they just plain explode!

My next set will be forged.

Rick

[wilf leek]

Hyper pistons have their place IMHO, in engines that won't see forced aspiration or NOS. True, they won't stand up to detonation well, but an engine should not do that anyway if it is set up right, surely detonation is a symptom of an incorrect build/set up.

Hyper pistons do run much tighter bore clearances than forged - no piston slap at cold. And let's face it, there are millions of production vehicles out there quite happy with hyper pistons, many with far higher specific power outputs per liter than these dinosaurs.

Andy - thanks for asking, I'm fine thanks, annoying these good (and some very bad) American folks on a regular basis these days.

Your spec is fine for what you want out of your car, but...... I still would advise against that oil pump - you are asking for distributor drive gear problems if you go with it, do a search here for similar tales of woe. A street engine, built to street bearing clearances, and with the kind of rev limit you propose will be more than happy with the std pump. Make sure that you check the clearance between the pick up and the bottom of the sump - stick to manufacturer's recommendations.

You may be too far down the road to change, now that you have some parts on hand, but I still think you should consider the 351 as a base. Overall engine dimensions should not be a problem in the GD - if a Cleveland will fit, so will a 351W. And how many GD's are there in the UK with Chevy 350s? D*mn their eyes.

Your performance expectations WILL change as you get used to your car - you WILL want more power!!

However - always remember that is is YOUR car, you build it just how you want. Putting a Ford engine in a GD is a fine thing to do!

[Andy(UK)]

Wilf,

Thanks for the insight, I will think about the oil pump issue, it didnt cost a great deal and I can always sell it on as its brand new.

tell me more about the differences between H.V and standard pumps, I thought it just pumped faster I didnt consider any other system knock on.

Thanks again, logging off for tonight but will check back tommorrow PM.

Cheers

Andy

[wilf leek]

Andy - pure race engines are built with far larger bearing clearances than street engines. This is because they are seeking to minimise friction, and don't care about the trade-off in longevity.
In that situation, a pump capable of moving higher volumes of oil than std is needed to maintain pressure in the system, and hence maintain the oil film at high rpm in critical bearing areas like mains and rods.

In a street engine, the bearing clearances are smaller. Less oil volume is needed. The std oil pump has more than enough "volume" capacity to cope. (You would probably find that even with a std oil pump, more oil escapes through the pressure relief valve than goes through the bearings anyway).

The power required to drive the oil pump comes through the distributor drive gear from the cam and down through the oil pump drive shaft (buy an uprated one incidentally) via the hexagonal hole in the bottom of the distributor drive shaft. This is one area of potential failure on the Ford SB, and putting a HV pump on increases the power needed to drive the pump, hence increases the chances of distributor drive gear failure.

Since a broken dizzy drive gear means an engine strip down to get rid of metallic debris, it is worth taking steps to minimise the potential for failure in this area.

IMHO, HV oil pumps in street engines fall into the "bragging rights" area.

Phew. HTH.

[Turk]

So, Wlf got kicked out of English Cobra Site. That's understable.
Why must we get stuck with him?

Can we send one of our discarded members over there as an exchange?

Andy. We don't like him either..

It was those damn cats, wasn''t it?

TURK

[Frank Gleason]

Goodbye Turk, hope you enjoy the isle

[Excaliber]

The fact that many manufactured engines come with hyper pistons does not sway my opinion of them, I don't like them.

Manufacturers like them because their quiet, cheap and will the job "good enough" for the design of that engine.

Detonation can and will happen at some point. While "dialing the engine in", playing with different settings, etc. Most likely the hyper pistons will still be "OK" with some limited detonation (limited in time and severity).

NOS? Turbo? Super charger? Don't even think about hyper!

,,,,dump the high volume oil pump, it was cause more trouble than it's worth.

Ernie

[Andy(UK)]

Thanks for the information, you tell a good tale that Im inclined to believe. Hence the HV pump is now up for sale in the UK!! (not lost alot if it dont go!)

One standard pump with hardned shaft to be ordered.

Thanks Again.

Andy