Tracking a SPF

[Seymour Snerd]

Not sure where you’re coming from there Alan. There was no reference whatsoever in this post to aluminum blocks being made in the image of iron blocks of course until you raised it.

I'm coming from the same place as Larry: repeating some advice given by "pro-shops" with respect to 60's-based Ford pushrod engines that were originally designed for iron blocks using aluminum blocks instead.

This is, after all, a thread on tracking a GT40 with a Ford 302 engine (see the original post.)

Nobody in his right mind would argue that aluminum blocks in general are a bad idea. I think you're correctly and eloquently arguing against a proposition nobody made.

 

[Jack Houpe]

I do open road racing, at least 65% of the entrants are late model corvettes, to me they are the best car and motor on the road today for performance bang for the buck, little to any have had motor problems as I can recall and all have aluminum engines.

In the sixties, GM had the small aluminum motor in one of their cars that was not successful here in the states and sold the rights to Rover, I think that little aluminum motor is still in some late model British cars today.

 

[Jack Houpe]

I'm coming from the same place as Larry: repeating some advice given by "pro-shops" with respect to 60's-based Ford pushrod engines that were originally designed for iron blocks using aluminum blocks instead.

This is, after all, a thread on tracking a GT40 with a Ford 302 engine (see the original post.)

Nobody in his right mind would argue that aluminum blocks in general are a bad idea. I think you're correctly and eloquently arguing against a proposition nobody made.

I have been told by 3-4 'big name' pro shops that after market alum blocks (not factory blocks) are really a no-no for the street. Reasons: (1) the constant heat, cool, heat, cool, partial heat, completely cool, hot to partial cool and back to hot again, etc., etc. over time (they all said that means within 5K miles or so) will cause the cyl bores to 'go oval on ya'...and the mill will start blowing oil past the rings. Why? Because after market blocks don't have the extra 'webbing'/'stiffening' that the factory blocks do, they're just made thicker...and they tend to twist/warp/distort because of it; (2) Alum blocks create more engine compartment heat than an iron block due to more rapid heat dissipation...& therefore more heat transfer to the pass. compt (and wherever else!), and, (3) an all alum engine will make and 'broadcast' more internal engine noise when running. An iron block doesn't let as much internal noise 'escape', if you will.

I have an dart aluminum block with AFR aluminum heads, just clicked over 12k miles in CA for which some of them where 3 open road races with average speed of 110 MPH for 118 miles, 2 track events and at least 100 BONZI runs under my belt. So you mean to tell me that this race motor driven on the streets is not going to last? How many miles on your car?

This is going to start a pissing contest so you do what you want, but use common sense and not rumor has it. Have a great day over and out.

 

[Sean]

I have been told by 3-4 'big name' pro shops that after market alum blocks (not factory blocks) are really a no-no for the street. Reasons: (1) the constant heat, cool, heat, cool, partial heat, completely cool, hot to partial cool and back to hot again, etc., etc. over time (they all said that means within 5K miles or so) will cause the cyl bores to 'go oval on ya'...and the mill will start blowing oil past the rings. Why? Because after market blocks don't have the extra 'webbing'/'stiffening' that the factory blocks do, they're just made thicker...and they tend to twist/warp/distort because of it; (2) Alum blocks create more engine compartment heat than an iron block due to more rapid heat dissipation...& therefore more heat transfer to the pass. compt (and wherever else!), and, (3) an all alum engine will make and 'broadcast' more internal engine noise when running. An iron block doesn't let as much internal noise 'escape', if you will.

I have an dart aluminum block with AFR aluminum heads, just clicked over 12k miles in CA for which some of them where 3 open road races with average speed of 110 MPH for 118 miles, 2 track events and at least 100 BONZI runs under my belt. So you mean to tell me that this race motor driven on the streets is not going to last? How many miles on your car?

This is going to start a pissing contest so you do what you want, but use common sense and not rumor has it. Have a great day over and out.

Out of interest, what spec motor do you have, and who built it, sounds along the lines of what I seek..

 

[Jack Houpe]

Motor was built by a company thats gone under, T and L out of North Carolina, they use to build nas truck motors for the teams till factories took over and gave the teams motors so they tried to build motors for hot rodders. They had a bad rap and I was truly worried about the motor, what was to take 2 months took 6 months but they produced a good motor for me, it originally had webers but I couldn't get it to fit safely without breaking the rear window out so I converted it to TWM throttle body injection. Its dart aluminum 351W block bored to 427 with 225 AFR heads, and solid roller cam. If I had to do it all over again I would go with dart aluminum 302W block bored to 331 which would make a more pleasant driving car with no surprises, but if your a HP junky do what you want. My personal choice of engine builders would be Keith Craft which is close by and has an excellent tract record from what I've heard.

 

[Sean]

Motor was built by a company thats gone under, T and L out of North Carolina, they use to build nas truck motors for the teams till factories took over and gave the teams motors so they tried to build motors for hot rodders. They had a bad rap and I was truly worried about the motor, what was to take 2 months took 6 months but they produced a good motor for me, it originally had webers but I couldn't get it to fit safely without breaking the rear window out so I converted it to TWM throttle body injection. Its dart aluminum 351W block bored to 427 with 225 AFR heads, and solid roller cam. If I had to do it all over again I would go with dart aluminum 302W block bored to 331 which would make a more pleasant driving car with no surprises, but if your a HP junky do what you want. My personal choice of engine builders would be Keith Craft which is close by and has an excellent tract record from what I've heard. On indiction most people recoment a 4 barrel although itlacks eye candy appeal

Thanks, I am thinking of a KC motor 302 based. The 3.25 stroke with a 4.125 bore. that would be the same stroke as a 331 but bigger bore yeilding 347. Most 347 motors have a 3.4 crank, but hen why not just go for a 363 with hydraulics.

So a big bore 347 seems like a sweet spot of a smooth reving motor with great power.

How often do you have to adjust the valve lash on your motor, do you have shaft rockers?.

Interesting that you say dont overdo the power, that is what I belive too, esp if you want to go to a race track, plus a lighter motor should pay dividends in braking and cornering..

 

[Jac Mac]

The vettes though are not DOHC. They are however hydraulics and the z06 have a 7100 redline. Which is interesting because a SBF is limited to 6500 with hydraulics.
The z06 also have Titanium conrods and valves and a 1.51 to rod ratio.
Was at the track last week and two vettes dropped valves.

The ford GT is of course a completly different story as it a modern non pushrod motor.

Anyone with a reasonable lateral thought process should be able to come to a sensible conclusion about that 7100 redline after witnessing the two dropped valve incidents

 

[Sean]

Anyone with a reasonable lateral thought process should be able to come to a sensible conclusion about that 7100 redline after witnessing the two dropped valve incidents

To me a dropped valve should have little to do with hydralics? more like the valve material(titanium) weaking with use. Maybe light titanium valves are how they get to 7k with hydraulics.

Or are you saying that no pusrod v8 hydralic or solid is going to be rliable over 6500k for too long?

 

[Jack Houpe]

I have my rev limit set at 6500 and hit it pretty quick with the aluminum flywheel and low weight, they tell me 7500 would be fine but I don't see any reason for it. At 6500 the 180 degree headers sound like a bee in your ear anyway.

I've checked my valve lash before every race just for piece of mind, they have never been off much it any at all. I also check my bronze distributor drive gear even though I don't have a distributor before every race to make sure the oil pump will continue to do its job.

My point is there are many good motors out there cast iron and aluminum, I personally wouldn't rule out one for the other, its a matter of cost and personal taste.

 

[Keith]

So 2k per year, say 1500 of which is on track with soilds and shaft rockers should last the year between adjustments then?

There is always a time at the beginning ont he season and end when I have the day to mess witht he car, in between its gotta be as simple as fuids and pad changes.

Good Lord...... :stunned:

 

[Mike]

Good Lord...... :stunned:

This one time you actually make sense lol.

So 1500 miles of track time with just fluid and pad changes? Now I'm just a ricky racer doof with a street car but I can tell you that my days on the MX/SX circuit suggest that desire has no connection with reality whatsoever. We would disassemble and rebuild drivetrain and suspension components after each weekend with maybe 2 hours of track time max.

 

[Sean]

Maybe its not for me then. I do about 2k per year on track with my lotus elise. Other than oil every two days and pads as needed it goes for 12-15 track days per year no problem. Each spring I change out the brake fluid and tranny fuid. Other than that and an alignment here or there and of course tires its needed nothing for the past 3 years,

Of course we check bearings bolts etc, but that is about it.

I know someone with 40k miles on his porche Gt3 15k of which are on track, other than fluids rotors and pads his car is fine.

Maybe moderns are just that much tougher.

None of the racers I know rebuild suspensions every race, maybe thats an MX thing.

I see vettes at the track that have been running for years without major rebuild.

Other loti have close on 20k miles before suspension bushings and the like go. Ohlins shocks seem to be good for 5-7k on track.

Now maybe a GT40 is old tech, maybe a SBF cant go 1500 track miles without major work or checking, which is whatseems to be said here..

Back to my origional question, does anyone here actualy track or race their Gt40 and what is required to keep the car running well.

Additionaly even if you dont have a GT40 but acar with a SBF that you track road race etc, what is required for the motor.

Yes I understand a Nascar motor lives at 9k rpm and needs redoing often, but a solid lifter sbf running to 7200 what is required there.

From what I hear a hydralic motor should be fine for 15- 30k depending on use, solids more like 15k, but maybe engine builders are blowing smoke.

Figure if a GT40 raced at lemans, 24 hours must have gone 3k miles before the race ended.

 

[Sean]

I have my rev limit set at 6500 and hit it pretty quick with the aluminum flywheel and low weight, they tell me 7500 would be fine but I don't see any reason for it. At 6500 the 180 degree headers sound like a bee in your ear anyway.

I've checked my valve lash before every race just for piece of mind, they have never been off much it any at all. I also check my bronze distributor drive gear even though I don't have a distributor before every race to make sure the oil pump will continue to do its job.

My point is there are many good motors out there cast iron and aluminum, I personally wouldn't rule out one for the other, its a matter of cost and personal taste.

Thanks for the practical feedback.
I understand the 6500 rev limit, but you have a 351 based motor. A 302 based motor needs to spin a but more and on a road course a broad powerband may well mean a few less shifts.

BTW how long does it take you to check your valve lash, do you have shaft rockers?

 

[Howard Jones]

It's not reasonable to expect that a car, any car, or a skateboard for that mater can be safely taken to the track even once without a "preflight" preparation and inspection.

I bet if we all start talking about the stuff that went wrong at the track this thread will really get going but I leave it to at least check all the suspension bolts, half shafts, fluid levels, seatbelt and safety equipment hardware, wheels and tires, belts and engine accessory mounts and hardware, body latches and mounts, shifter mechanism, and just about every thing on the car that can fall off.

I call these things "it el kill ya parts" I got that from a pair of handlebars that broke on a motocross bike 40 years or so ago. I'll never forget that again!

Please rethink that once a year thing. You are our mutual friend and we care about you.

 

[Jack Houpe]

It's not reasonable to expect that a car, any car, or a skateboard for that mater can be safely taken to the track even once without a "preflight" preparation and inspection.

I bet if we all start talking about the stuff that went wrong at the track this thread will really get going but I leave it to at least check all the suspension bolts, half shafts, fluid levels, seatbelt and safety equipment hardware, wheels and tires, belts and engine accessory mounts and hardware, body latches and mounts, shifter mechanism, and just about every thing on the car that can fall off.

I call these things "it el kill ya parts" I got that from a pair of handlebars that broke on a motocross bike 40 years or so ago. I'll never forget that again!

Please rethink that once a year thing. You are our mutual friend and we care about you.

:thumbsup:

 

[Jac Mac]

To me a dropped valve should have little to do with hydralics? more like the valve material(titanium) weaking with use. Maybe light titanium valves are how they get to 7k with hydraulics.

Or are you saying that no pusrod v8 hydralic or solid is going to be rliable over 6500k for too long?

No easy way to say this & I am not trying to offend you, but your understanding of hydraulic lifters & how they operate seems to be a bit light! As soon as you reach the lifters limit of ability to keep the valve train under control it will 'pump up' in order to take up the slack, that 'slack' can occur at any point in the valve train-[ between lifter & cam lobe- lifter & pushrod-pushrod & rocker-rocker & valve stem tip-keepers & retainers-retainer &valve spring-valve spring & spring seat/head ] depending on the components being used....once the lifter is pumped up the valve will not be able to 'seat' until the RPM or whatever has caused the problem (your right foot ) is removed. During that 'unseated' phase the valve heads may contact the pistons, coil bind of the springs occur, retainers contact stem seal or valve guide & in the case of an inlet valve they stuff up the induction signal in the runner of the manifold which can cause further issues if your running close to the limit for an extended time... there is an interesting thread by Brent Lykins on Club Cobra at the moment which may be of interest to you on the buildup of an alloy 331 for Cliff Rosson that Brent Dynoed prior to delivery & the stuff we are discussing here happened to Brent on the Dyno- roller hyd cam pumped the lifters up @ 6200- so they are now going to a flat tappet cam. The problems I see with Hydralics is there are so many variables outside of the cam that can affect them, cold oil, different start techniques for different drivers, ignition timing & carb issues causing spit back etc...the list goes on..Engine builders remember two types of engine, those that win & hopefully to a lesser degree those that break, they also remember two types of owner, those that respect the engine & those that dont...pick one!

 

[Howard Jones]

I'm not going to tell you anything about who, what or where but he did walk away. The details are not really important as to what type of car, what he did or did not check or how often or whatever but something DID BREAK and/or COME APART in the rear suspension, not the steering by the way.

Ya gotta check things between sessions.............. let alone weekends.

[ame=http://www.youtube.com/watch?v=e-9XSOM5eIo]Cobra Crash Willow Springs, Short version 130 mph - YouTube[/ame]

 

[Sean]

It's not reasonable to expect that a car, any car, or a skateboard for that mater can be safely taken to the track even once without a "preflight" preparation and inspection.

I bet if we all start talking about the stuff that went wrong at the track this thread will really get going but I leave it to at least check all the suspension bolts, half shafts, fluid levels, seatbelt and safety equipment hardware, wheels and tires, belts and engine accessory mounts and hardware, body latches and mounts, shifter mechanism, and just about every thing on the car that can fall off.

I call these things "it el kill ya parts" I got that from a pair of handlebars that broke on a motocross bike 40 years or so ago. I'll never forget that again!

Please rethink that once a year thing. You are our mutual friend and we care about you.

I dont disagree with what you are saying. Its one thing to put acar on a lift and check bolts. BTW I check my wheel nut torque(when cool) every time I go out, which can be several times in a day. My oil is changed every two days on track, I use motul single ester oil, synthetics in the tranny etc..


The question more specificaly is what needs doing on a regular basis, and can a sbf with solids go 1500 miles between lash checks. The engine builders say definitly, others say more like 500 miles. The question is because I have never done valve lash before, and I am pretty sure its a n hour or more. Since it takes me 3-4 hours to check a car anyway, load it on the trailer spare wheels etc I am not sure its worth going with soilds and not just go for a larger motor with hydraulics.

Now if a SPF always has bits comming losse, like some shed built race car, its something I want to think about.

Oltroff told me his clients race cars go 2 seansons of races every other weekend before redo.

But maybe there is a lot of bolt tightening along the way?

 

[Sean]

No easy way to say this & I am not trying to offend you, but your understanding of hydraulic lifters & how they operate seems to be a bit light! As soon as you reach the lifters limit of ability to keep the valve train under control it will 'pump up' in order to take up the slack, that 'slack' can occur at any point in the valve train-[ between lifter & cam lobe- lifter & pushrod-pushrod & rocker-rocker & valve stem tip-keepers & retainers-retainer &valve spring-valve spring & spring seat/head ] depending on the components being used....once the lifter is pumped up the valve will not be able to 'seat' until the RPM or whatever has caused the problem (your right foot ) is removed. During that 'unseated' phase the valve heads may contact the pistons, coil bind of the springs occur, retainers contact stem seal or valve guide & in the case of an inlet valve they stuff up the induction signal in the runner of the manifold which can cause further issues if your running close to the limit for an extended time... there is an interesting thread by Brent Lykins on Club Cobra at the moment which may be of interest to you on the buildup of an alloy 331 for Cliff Rosson that Brent Dynoed prior to delivery & the stuff we are discussing here happened to Brent on the Dyno- roller hyd cam pumped the lifters up @ 6200- so they are now going to a flat tappet cam. The problems I see with Hydralics is there are so many variables outside of the cam that can affect them, cold oil, different start techniques for different drivers, ignition timing & carb issues causing spit back etc...the list goes on..

Hey I am here to learn and talk, as much knowledge and experience as you are willing to share I would appreciate learning.

From what you said above I can see how on a z06 the valve could contact the pistoon and break. I had assumes that titanium valves are more fragile and prone to stress cracks so had a higher failure rate.

BTW on a solid roller cam motor, what would you use for valves, soild stainless, hollow stainless of titanium?

 

[Howard Jones]

It's hard for me to really think of anything that you don't have to check. I did tech a couple of times and I can't tell you how many loose wheel bearings I found. I'm talking about a eighth inch of free play for god sake. People just don't know because they have never run a car hard for a couple of hundred miles in a week end before and they just don't realize how much stress it puts on things.

My advice is to talk to some other guys at the track and start to make a check list. Pre weekend, beginning of second day, between sessions, and return to garage. Then a maintenance schedule such as oil changes, brake fluid change out, brake pads, belts, repack bearings, etc.

Make this a living document that gets more refined as you progress. After a couple of years you will have a pretty good idea what you cars needs.

I am one of the, easy on the HP, people around here. 5500-6000RPM 351 SBF with hyd lifters @ 400Hp is all that is needed for a very fun open track car. Save the rest for good brakes and tires. Start slow and on street tires, and when you feel that the tires are the limiting factor of your lap times then think about another set of wheels and Hoosiers.

A word on driving schools here is also in order.

If you can get a 400hp GT40 lapping as fast it can on slicks then you're there baby!