SLC 24 Howard Jones

[Howard Jones]

When I built my GT40 I didn't do a build log. So this time I will begin at the very beginning. I Ordered the car on Sept 19th when I was there. I asked Fran to hold off shipping until after the 1st of the year and that fits right into his 16 week delivery schedule. So in the mean time I'm collecting parts.

Here I am at RCR trying one on. And as you can see I have begun collecting parts. I visited California Motorsports last September and spent a couple of hours there. We went over what I wanted to do and came up with a G50 XX with a 2.4 1st,1.75 2nd and a 3.44 final. It also has a Quaife TBD in it along with steel syncros, steel shift forks and, billet side plates.

I also found these Brodix heads IK 200's on their web site. They were in the overstock section and I got them for $900 including shipping. As you can see I am going to use Pro Magnum Comp rockers on them also. And yes I have gone to the dark side. It's gonna be a Chevy.

The plan is a 4 bolt 355 at 10.3 to 1 compression, Scat forged crank, rods, pistons and a retro fit hyd roller cam/lifters are all on order. Target power is 425-450HP.

This car is going to built from the outset as a track car. Ought to be interesting

As more stuff arrives I continue posting pictures.

 

[Rick S.]

if you need help unpacking the slc let me know. I live right up the street.

 

[Howard Jones]

Some more parts arrived. Sometimes I think that this is half of the fun of building a car. I really enjoy the research part of a build. It's really amazing how much there is to learn as you go through the process of selecting parts and matching them together to achieve a goal.

So here is the cam and lifters. The block I am using is a 1985 4 bolt truck block and as such it isn't designed to use hyd rollers. Comp Cam and others such as Crain do however make a retro fit roller lifter kit. This is what you see. The advantage is it's not necessary to install a spider in the lifter valley and the lifters are "dog boned" together. This technique is used in most racing solid roller systems to maintain roller alignment on the cam lobes and not add the additional preload to the lifters other than the valve springs that the spider system does.

There is also the added reliability of not being concerned with the spider legs breaking due to fatigue.

The cam is a XR294HR Comp Xtreme. The specs are, duration/lift intake 294/.540 and exhaust 300/.562 and 110 lobe sep. angle. This is next to the hottest cam that they make for a hyd lifters. The engine machine shop guy and I went over the Comp catalog for some time talking about cam choice. What it really comes down to is octane numbers and engine RPM range.

I want to run this motor from 3000-6500 on track and on pump gas. In order to run the biggest cam (I 300/.562 E 306/.580) in the catalog he believes we would have needed to go up to 11 to 1 static compression. This would result in about 10.6 to 1 dynamic compression with that cam. It also would have pushed the rev range up another 300-400 RPMs. Any lower compression and the added duration would be wasted.

So we went with the 294 cam. The resulting dynamic compression will be right at 10.2 to 1 and with aluminum heads, right at the limit of 91 octane California gas. We both expect to see good power and and a nice flat torque curve starting at 2800 and extending to 5500-5700. The rest of the engine parts have been selected to give very good reliability and long life up to the planned rev limit of 6500 where we are hoping for 425HP.

I will post again as more parts arrive. Scat rotating assembly next. Then I get the block back from the machine shop and start putting it together.

 

[Howard Jones]

The pile of engine parts is getting larger. Intake in a Weiand X-Celerator single plane. I called them and they believe that this intake will be just right for the power-band and cam/valvetrain package that I am going to run. The rotating assembly is in the big Scat box. It is the forged crank/pistons/rods package. The rods are their I beam type. Pretty sure they will be fine at the rev limit I will be using.

Plain alum valve covers. They will be getting bungs welded into them for a oil fill and crank case vent system so nothing special here. The MSD disturbutor is a billet type meant to be used with a 6AL box that I already have. The crank dampener is a BHJ. Very good part and I got a very good price. Lots of these on circle track cars around here. Lastly is a aluminum timing cover from Summit. Cheap and functional with a thrust plate in it.

So I waiting for the flywheel and clutch to arrive and then it all goes to the machine shop to get balanced.

 

[Scott Calabro]

"The cam is a XR294HR Comp Xtreme. The specs are, duration/lift intake 294/.540 and exhaust 300/.562 and 110 lobe sep. angle. This is next to the hottest cam that they make for a hyd lifters."


Hi Howard,

With that camshaft, this is a really good idea, along with a regular lifter inspection interval due to those required heavy valve springs.

Especially with track work.

Ti retainers would help too.

AFR Cylinder Heads Inc: Aluminum cylinder head manufacturing and flow dynamics

Regards,
Scott

 

[Lukas Matzinger]

Howard,

Definitely an interesting build - modern looks with an old school carbed engine. Should sound bad ass too with that cam!

I am guessing that the SBC has the ports in a different location that the LSx. Does Fran have different headers available or will you be supplying your own?

Cheers,
Lukas

 

[Howard Jones]

One reason I'm using a early version of a small block Chevy is cost and complexity. The other is I have a very knowledgeable source for advice very close by and he has taken a interest in this car. And I really don't like computers and excessive electronics on a track car. I have seen a lot of time wasted at the track trying to get one thing or the other working, all the while all the other Holley car just go around and around. I also am trained in electronics and while there is some really cool stuff out there, I don't believe that I need any of it to achieve my goal.

425-450HP
Near perfect gearbox setup including Quiafe LSD and gear ratios.
Total car weight dry without driver less than 2300Lbs.
10" wide front and 12" wide rear slicks
Near perfect brakes.
Modern aero, good down-force. No lift.
Fully tunable suspension geometry.

I will be able to build this motor for quite a bit less than $5K including labor. What I get is a 4 bolt 355 with very good CNC ported alum heads, full hyd roller valve train including Comp CM roller rockers, forged rotating assembly with the compression ratio and cam timing specs of my choice. I'm gonna put a 750 Holley on top of a single plane intake that is just about perfect for a 6400-6600 RPM motor. The machine shop/racer friend of mine say "don't be surprised if you get quite a lot more HP than your target of 425-450" So we'll see. Outta go pretty good in a stripped down track version on slicks.

The machine shop and balance work is being done by someone who I have experience with and I have full confidence in.

All that for about $4800. Why would I do otherwise. With the saving I can put a lot of money into the rest of the power-train and follow my golden rule. "The central and most important aspect of a mid engine car is the trans-axle, its gear ratios, limited slip, and durability". So I have spent about about 3/4 of my power-train budget on the stuff that comes after the engine.

As far as the headers go I believe that Fran makes up a set of headers with each car. I do know he wanted to know what heads I was using.

Scott, That Hydra Spring thing is pretty interesting. I did choose the valve springs and retainers that Comp recommended with the cam and other parts. They said that I should set rev limiter to 6500 Max and shift between 6000-6300ish. HUmmmmmmmm. Those HP numbers look pretty good @ 6K rpms. I may need to dial it back a little.

 

[Craig Gillingham]

i am a bit narrow minded sometimes and think a modern design needs a modern engine...but thats just me....bit like colour choice and art...nobody is right and nobody is wrong....

keep us informed of your progress

just wish i had some of you guys skills to have the confidence of doing my own build...

 

[Howard Jones]

Craig, I know what you mean, and I agree.....to a point. The point where I begin to put together a budget. I had originally considered doing a 13B 425Hp turbo. It would have cost 4 times the SBC, just to get it into the car. God knows how much it would have cost to develop it. Frankly I think that the torque from the Chevy would make that package faster on the lap. After all the inter-cooler plumbing and stuff I not sure the Mazda would be much lighter either. I talked to several rotary people about this and in the end I couldn't see why I would do it.

The LS series is certainly a more advanced motor. Its probably the best V8 available. I just have to build this car so it will work without a lot of costly trial and error, meet my performance goals for me, and within a budget that I can justify. I could have certainly spent more. But again the question is why.

Life is a series of compromises I guess. "Sometimes you just gotta know your limitations".

The same thing is what pushed the 917 out of the picture for me. The flat 6 Porsche is at least 12-$20K to do it right at 425HP. Too much custom stuff. Just think about how much it would cost to put a horizontal fan on it for example. $140 water-pump looks pretty good and it will work the first time it turns over.

I do like unique cars. The SLC is surely unique.

 

[Howard Jones]

Here's the last shipment from California Motor Sports. Now that I have the clutch and flywheel I can get the rotating assembly balanced and put together the short block. I want to have the motor more or less in one piece when the car arrives so that I can mate up the gearbox and try them on for size.

The one thing I will need to do first, is put the pulleys on the front of the motor and mount the alternator. I intend to make all of my own brackets like I did on my GT40. I think it's just easier some times to start with a clean slate and make things yourself. At the least you don't end up with brackets you paid for that don't fit. I will need to put the motor into the chassis first so that I can have a look at clearances. Then I can make up a alternator mount. I want the alternator as low down in the chassis as I can put it, more or less along side the crank pulley .

Here's the picture of the clutch parts, Kennedy Flywheel, TO bearing, pilot bearing/ adapter, and starter.

Merry Christmas all, more next year.

 

[David Briggs]

Looks like a fun project Howard and should be very quick as well.
Dave

 

[Jack]

I had a new ZZ-383 crate engine, still on the pallet. Sold it & got the LS engine for my SL-C because I believed that a new design deserves this set-up. The reality is that it cost about 4 times as much as anticipated to do it right! If I had to do it over, I would have built a fresh SBC with a 6000 RPM capability and around 400HP max (street car). The LS engines are really great but the harness, ECU & reprogramming, TAC module as well as the mod's (heads, cam, springs, lifters, pushrods, etc.) to bring my LS-1 to 430 HP almost busted my budget. But it's done and I'm a very happy camper with the LS engine. It really looks like it belongs in the SL-C.

 

[Howard Jones]

Molleur, After the car is done, someday I may upgrade the carb to a 8 stack F.I. But for now I just want to get the car completed to a performance level that I believe I can run with the fast guys at track days and not be in the way. That means about 20 secs a lap faster that I am going now in my GT40. Granted I am on street tires and I think I can take a big chunk of time out a lap with tires, but in the end I am going to need a deadicated track car like the SLC with about 450HP, very good brake performance and really good grip.

My friend agreed with me that I didn't need to add CI's with a 383 stoker but what I needed was a carefully built 350 with the proper valve timing. So that's what I gonna do. Remember I need to run this car on California 91 octane pump gas with maybe a splash of 100 octane unleaded race gas to bump it up to 93 or so.

My complete power-train budget is about $22K with about 4500ish in the motor. I did trade a big Costco bottle of Jack for the block but that really only saved me a couple of hundred or so. I intend to save some money on assembly other than the machine work so really those dollars represent the sum of the parts plus 400 buck worth of balance, bore, and weight matching the pistons.

I wouldn't have been able to do this car now if I had to spend 20K on a motor.

 

[Jack]

Howard,
I would have sold the 383 anyway and did as you are doing. A reliable 400-450HP SBC with the right parts. Still cheaper that way. I have a bit more than 7K in the LS engine & associated electronics. You can build a 'bitchin-high 'revvin SBC for much less than that! The SL-C really handles well and with the "track" suspension & sway bars it will really stick. 20 seconds a lap is a lot! Where are you running the GT40?
Jack Molleur...

 

[Howard Jones]

Thunderhill in Northern California. Trackmap It is 3 miles in lenght and I use 3rd and 4th gear all the way around. I am doing about 2.25s without sliding the car around or much drama now and a 2.10 - 2.05 would put me right up with the front of the fast group. Now the other thing is the driver of course. I'm pretty comfortable with the high/middle of the middle group and I believe I can go a little faster. Maybe a sec or two with my GT40, but it's a duel use car and I want to keep it in one piece so I can participate in the road meets and club events.

Now whether I can go that fast is to be seen but I would like to have a car that CAN go that fast. Then we will just have to work up to it.

Just so you know. The track record is held by a Formula Atlantic 1:39 and the GT1 record is 1:47.8.

 

[Jack]

Howard,
Just watch the seconds melt away with the SL-C! I am not aware of any real road course lap times with the SL-C as yet, but I did get Ernie's time (675HP) around Palm Beach Int'l Raceway. He wasn't really pushing and easily kept pace with some very fast cars. Very respectable. The acceleration was incredable.

 

[Howard Jones]

All the talk in the engine and power train page got me started on the vent system on the SBC going into my SLC. Here's some pictures of the valve covers. They are a standard cast tall no-name but should do the job.

I changed the baffle internally because the ones that come with the covers are a screw in type. I don't like the idea of loose parts inside a valve cover so I made my own and welded it in place. The big bungs on top will be drilled and taped for AN-10's per Jac Mac.

The fitting shown in a AN-8 just to show the idea.

 

[Jim Nielsen]

Howard,
A couple thoughts, When you rally start pushing your car on the slicks you will be generating higher cornering g's. The carb if not a road race setup may cause fuel starvation issues. Another thing is keeping the oil pickup in oil unless you go to a dry sump.
Had you considered a used vette LS engine? You can buy these older LS's complete with wire harness and computer in the 3 grand range. This would eliminate the carb problem and drop weight off the car. Don't these put out 400 hp stock? Going to free flowing headers and a cam change should put you near your hp goal. You could in the future add heads when you wanted more HP but you would always have the lighter weight benefits. It is also much easier to learn to drive the corners with less hp. Something I would recomment is a lightweight flywheel and clutch, multiplate if you can afford it. Makes the engine much more responsive.
Good luck
Jim N

 

[Jac Mac]

Howard,
Sorry I didnt pickup n this earlier, but you have slightly misread my reccomendation for placement of the breather/s. I mount them on the 'wall' of the cover nearest to the carb, as high as possible & in between any pair of pushrods. In the case of your chevy & due to the position of the rocker cover bolts the placement would be between cyl# 3-5 and 4-6. These are the two areas within the covers that are least likely to get splash oil during cornering etc.

 

[Howard Jones]

Jac, I did my SBF just like this one and ran the hoses to a catch tank. I have yet to find any oil in the can other than vapor residue. The other thing is these valve covers have 1 1/8 holes in them that need to be covered one way or the other. Thus my choice of position of the breather bungs. If I had some valve cover without any holes in them then I would have tried you way.

J, I am using a Canton road race pan with correct baffles and trap doors etc. They really make a good well designed pan and I have one on my GT40. I have never had a oil issue yet. I will also install a remote oil cooler plumbed from a filter adapter. This system holds about 8 quarts of oil total. As far as the carb issue. I have pretty much solved the corner starvation problem with the Holley on my GT40 with jet extensions, careful float adjustment, different floats and playing with fuel pressure. As far as the LS series goes, I have shared my view above. Great package but a guy's gotta do what a guy's gotta do.