Engine re-build

[Steve Mid]

I need the expertise of the forum to re-build the engine of my GTD Ford 302.
There is a rumble down below, altough the oil pressurs is fine, but I would like to upgrade the engine.
The present output is 280bhp with cast iron heads and I would like some ideas on how to increase the output to say 350bhp.
There are several companies in the USA selling aluminium heads at very reasonable rates and does anyone have any experience of them.
Some advice would be appreciated, thanks, Steve.

 

[Robert May Eng.]

I think the first thing you need to do is strip the engine down to find the cause of the noises. As far a tuning goes the 350hp is relatively easy to achieve and there are lots of ways to achieve it. If the crank is u/s it might pay to look at the balanced ready to go stroker kits. As far as heads go you need to remember you get what you pay for so too avoid disappointment go with a brand name. Just one of many suggestions you may get

Bob

 

[Andy Green]

Hi Steve,
I’ve used Edelbrock ‘Performer RPM’m heads & a matching cam (which is very mild and expect to achieve around 330Hp with good driveability. Have a look at my build log (Norfolk Tornado, page5) for further details

PM also sent

Regards,
Andy

 

[Robert C]

Steve,

With the 302 SBF, the possibilities are endless. The first thing you need to ask yourself is how will the car be driven. Street car or track car? These are two separate paths. Also, keep in mind that anything you change out will force you to address other aspects of the motor if you wan it to run right. For example, changing over to aluminum heads with bigger valves, combustion chambers, and ports is easy. However, this will force you to address the intake set up as well to make the motor breaths correctly. Same thing with a cam. I know a lot of folks that got a bigger cam, but did not pay attention to the heads. Next came an epic fail!

Edelbrock and a few others sell complete kits that sort this out for you up front. They already did the matching and homework, so every thing works together well. Comp Cams also has a downloadable tool that helps match things up and gives you potential out puts. You input the data, and it tells you what to generally expect HP and torque wise. If you play with it, it gives you some ideas to consider if you want to mix and match different suppliers of parts.

Finally, use caution if you decide to get a stroker kit. If you go past a certain stroke, you need to make sure there is clearance at the bottom of your bores for the connecting rods. Tell your machine shop the set up, and they can notch the bottoms out so you don't have collision.

Hope that helps you out a little.

Robert

 

[Dave Garner]

I changed from cast iron heads to Edelbrock RPM Performers heads, inlet, hydraulic roller cam and roller rockers this winter. Went from 267bhp to 320bhp on the same rolling road (so numbers are relatively comparable).

Stayed fairly conservative on the cam and have got superb flexibility AND a real 'kick' above 4500rpm. Just done 3 track days in France and much more powerful (on the paper) cars were not catching me.

Very pleased with the outcome!

I am running on a quad barrel 600cfm Holley carb. for info

 

[Andrew Robertson]

If you are contemplating an upgrade to heads, intake/carb, cam and valvetrain, and stroking it, it may be more cost effective to do this low deck package as a swap out and then flick your current mill for an offset in cost once you address the bottom end noise.

Shafiroff Racing 363 Small Block Ford Crate Engine

I have sourced an engine from them and was happy with the service, freight, and end product.

Cheers, Andrew

 

[Keith Stafford]

Steve, have a look at this article, Ford 302 V8 Engine Buildup- Car Craft Magazine

What gearbox do you have, will it cope with 350? K

 

[Robert May Eng.]

You really need to take some of the dyno figures quoted by the mags with a pinch of salt. Quite a few of these are "happy dyno" results as are many rolling road figures being punted about.

Bob

edit. Look at Dave Garner`s dyno results , that is a more realistic power hike for just bolting on heads.

 

[Robert May Eng.]

Some gumph from AFR

Bob

http://www.airflowresearch.com/ford_dyno.php

​

 

[Howard Jones]

First decide on what gas you will be using. Then what kind if lifters, and lastly round figure total HP.

First pump gas will work well at 10 to 1 compression ratio. You can get away with a bit higher with Alum Heads or better gas so a I think a 10.5/1 alum head motor would be fine with some margin to spare.

Then the lifters will determine the rest of the valve train and to an extent the rev range/limit. Hyd lifters will go to 6500-6600 and still be trouble free. Flat tappet or solid rollers will run up to the mechanical strength of the lower end or block and or the breathing limit of the heads depending which you reach first.

So I will assume pump gas and 400 HP. It is my believe that about 1.25 to 1.3 HP per cubic inch is about the limit for a street driven pump gas motor that will live for 50,000 miles without much maintenance beyond oil changes and valve train clearance checks from time to time.

So we are at 302 X 1.25 = 377HP, @ 1.3 = 392. If you are using new lower end pieces then we can bore to 30 over and stroke to 3.25 you get 332CI. 332 X 1.25 = 415HP Now you see why I like a 3.25 stroke. Good/safe rod angle, pistons will use normal ring configuration, you can still use a stock block and only clean it up with a 30 over bore, Plenty of crank kits available for this rod length and at 10.5 to 1 it will make 400HP for a long time without protest.

Now you need to support it with airflow. Edelbrock RPM performer head/cam/valvetrain kits will do just fine and I like the 2.02 intake 180cc intake port volume heads they offer. Good price and run well at street rev ranges of 2500 -6000.

IMHO this is the perfect combination to use with roller Hyd lifters/cam valve train. Check with Eidenbock for their recommendation of pieces at 400HP/331ci.

If you already have the block and assorted pieces just add ARP main cap bolts and you will be able to come in at around 6K$ here in the US with a few hundred into machine work and balancing.

Plop a 700 Holley DP on a RPM performer intake and you are good to go for years.

 

[Neville]

Hi Steve, one fellow Brit living in New York to another, one of the biggest considerations in building hi Hp cars is the gearbox, unless you have a ZF trans or something very similar keep the hp on the conservative side , 300 plus hp for a street car is very adequate, engines are easy and cheap, all the best for now, let us know how you make out, Neville Nesbitt.

 

[Mike Pass]

Hi Stephen,
Sorry to hear about your rumbles. What is your oil pressure? How does the noise change with revs? If your block is screwed there are quite a few 302 cut out motors on Ebay UK. I paid £200 for a good roller block. Check the bore with a digital caliper which should be 4.000" if it has not had a rebore. Usual rebore size is +30thou.
If you do need a rebuild then alloy heads are a good idea. By all accounts the AFR are the best (esp the CNC versions) but quite expensive. The Edelbrock RPM heads are good and maybe the best value on performance per £/$. I have had the Edelbrocks with the 2.02' inlets on my car for 10 years now and they are good. A point to note is that in addition to more power you lose 44 lbs per pair over the iron heads and this weight is high up. On the inlet side use a dual plane manifold for road use. The Edelbrock RPM AirGap gives about 15 - 20 bhp more than the standard Performer RPM and should fit OK under the rear clip with a 4brl Holley and a drop base air cleaner. Use a road type cam so you get good torque and drivability.
You don't say what power you want but my 302 with the Edelbrock RPM top end, roller rockers, road cam, performance Holley 650cfm double pumper and stainless c/over exhaust did 335bhp and 340ft lbs torque and has been thrashed for 10 years or more.
If you need more then go up in capacity. You will probably end up with a 30th bore on the rebuild and you can fit a stroker kit to take it up to 331ci (revs better) or 347ci(more torque).
A 347ci with the Edelbrock top end will do 400 - 450 bhp and 400 - 450 lbs ft torque if your gearbox will take it.
I am currently building up a 347 motor and have just had the block prepped with a mains line hone, decks trued up to crank line, deck plate bored and honed 30thou, new cam bearings, screw in oil gallery plugs and new brass core plugs, notching for the stoker kit and a very serious scrubbing and cleaning. It will have a steel stroker kit with a neutral balance steel flywheel, Edelbrock heads and an RPM air gap inlet.
There are lots of books on rebuilding and tuning SBFs. There are lots of people on here with a wealth of knowledge and experience for you to tap into.

Cheers
Mike

 

[Dave Garner]

The configuration that Mike describes above (302 with Edelbrock RPM head, Airgap inlet hydraulic roller cam Holley 650cfm carbs etc) is the same configuration I went to over winter (other than I stayed with the 1.90" valves) which on the same rolling road went from 267 to 320 bhp.
I am limited by my UN1 gearbox internals but the car seems to perform on track way above the 'quoted hp' I suspect because of its wide power band - and the 'optimistic' nature of quoted output from some rolling roads - hence my quoting the comparable figures on THE SAME rolling road.

Dave

 

[Howard Jones]

Dave and Mike. It's good to see some real HP numbers from your two engines. This could really help a lot of people who are asking "what do I do for a good street motor".
If you guys could state some basic cam data. At least total lift and duration or even just the eldenbrock part number we could figure out the rest.

My 302 with a B303 FMS cam and home ported alum X heads @ 10 to 1 CR with 750DP on top of a RPM perf intake made 297HP at the wheels on a chassis dyno that I trust (private tool of a race shop). The owner told me he believed the losses for everthing was about 50-60HP. So I was about 350HP and pretty much what I thought.

So our three motors taken in context make a lot of sence as good pumpgas baseline builds.

 

[Mike Pass]

Sorry but I don't have the specs of my cam as I didn't build this motor. However it is definitely a soft road cam as it pulls well from 1,000rpm and starts to run out at 5,5000 rpm.
Cheers
Mike

 

[Dave Garner]

Currently:
Power 320bhp, drives nicely from 1000rpm, pulls HARD from 2500rpm, step change at 4500rpm thru to 6000rpm as everything realy starts working together!!
Increase of 53bhp ON THE SAME ROLLING ROAD. Engine has retained a VERY WIDE and flexible power band.

The Holley is NOT correctly tuned yet, coupling that with the new Pertronics Distributor (with its more 'appropriate' ignition advance curve) may realease a few more horses .

So The Current Configuration:-
302 block with standard pistons

Edelbrock RPM Performer heads with 1.90" valves
Edelbrock RPM Performer Airgap Inlet manifold
Edelbrock Hydraulic Roller Lifters
Edelbrock Roller Rockers
Comp Cams Racing Pushrods

Comp Cams 282XR Hydraulic Roller Cam
Originally I went for an Edelbrock 2221 RPM Performer cam but I was not happy with the quality when it arrived hence the move to the Comp Cams 282XR which is a similar (but not identical) specification.

Windage tray
Canton 15-644 baffled sump (and pickup) - allowed engine to be lowered by 20mm

Standard oil pump but with uprated drive

Holley 650cfm Quad Barrel Carb

Pertronics 'Flamethrower' Coil
Pertronics 'Ignitor' module - replacing the points
Prestolite 'Marine' Distributor - Pertronics unit on order following the second rotor arm failure in 6 months - and this time the failure did a LOT of engine damage so the Prestolite is heading for the bin!

Previously: Power 267bhp, power then 'fell off a cliff' at 5250rpm.

The configuration was:
Standard (iron) heads
Edellbrock Performer inlet manifold
Rail type rockers
Standard cam shaft with hydraulic lifters
Standard rear sump

Hopefully the above provides a 'realistic' indication of what you achieve (as opposed to some of the 'fantasy land' claims the manufacturers make!)

Lowering the engine (even by only 20mm) and getting the top weight down with the Aluminium heads made a VERY BIG difference to agility on track.

Dave

 

[Dwight]

Call Keith Craft and ask about his CNC's Brodix heads with a Keith Craft spec'ed cam to match.



Keith Craft Performance Engines