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1.4L race motor needs more ...


TimGreen

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And I hate to sound all old man on you, but if he's learning, spend your money on brakes and suspension. Don't add speed until he is better than the car, and the car is capable of using it well. 

He is already going past the 200' marker so the brakes are working pretty good, but the car is not accelerating all the way down the two long straightaway's.  I think the taller diff will help for the next race and hopefully we will have solved the overheating with the radiator professionally cleaned and a new water pump (with cast impeller). 

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He is already going past the 200' marker so the brakes are working pretty good, but the car is not accelerating all the way down the two long

straightaway's. I think the taller diff will help for the next race and hopefully we will have solved the overheating with the radiator professionally cleaned and a new water pump (with cast impeller).

I think youve got the right idea here, it's a tough crowd here but they know there stuff. Get it in top shape then do the power upgrades.
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we will have solved the overheating with the radiator professionally cleaned and a new water pump (with cast impeller)

\

this is the correct direction to start with 

especially the cast impeller

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He is already going past the 200' marker so the brakes are working pretty good, but the car is not accelerating all the way down the two long straightaway's.

 

 

Then...

 

 

you really need to do this to the head. They respond best to a lot of porting work...

 

gallery_102_398_1483044659_33140.jpg

 

 

With good porting work they keep pulling and pulling until you pop a piston. Ask me how I know...   :rofl:

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You haven't said what experience level your son is at, so I assume he is new at it.

Speaking from a lifetime of racing experience, Don't get carried away with blaming the car ( not to say it cant be improved).

Let your driver get experience.

Driving an under powered car makes much better drivers in the long run, compared to drivers who just use mass power to make up for their lack of skill ( in my humble  opinion).

Patience! Have fun!

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You haven't said what experience level your son is at, so I assume he is new at it.

Speaking from a lifetime of racing experience, Don't get carried away with blaming the car ( not to say it cant be improved).

Let your driver get experience.

Driving an under powered car makes much better drivers in the long run, compared to drivers who just use mass power to make up for their lack of skill ( in my humble  opinion).

Patience! Have fun!

My grandson raced go-karts when he was young but had never raced cars.  He did his first drivers school and race 2 weeks ago, unfortunately we had over heating issues all weekend so he never got a chance to do multiple laps at max but we could hear as he went past on the main straight shifting from 3rd to 4th very little increase in engine RPM.  I agree we don't want to build a killer engine at this time but I would like one that revs above 5,500RPM.  I have been instructing wheel-to-wheel for years and totally agree, learning with limited power teaches car control and momentum driving.  Can't wait till 5/26-27.

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Your A series can't get over 5.5k? Is it getting enough fuel? I think they should review higher than that with just factory parts.

Please remember this is a RACE CAR, when I mention it doesn't rev over 5,500 RPM I am referring to its ability to accelerate FAST.  We shift up when the engine is out of its power band and this engine's power band is over at 5,500.  It was chassis dyno'ed in March 2011 with 50HP and 68.61 ft-lb torque.  It has an electric fuel pump at the fuel cell and is regulated down to 3.25 pounds very near the Weber carburetor.

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Those engines or cars were not meant to be a race car even if you have a 32.36 weber. They were design for saving gas. My mom had a wagon w a similar engine back in the days. Very slow....you will need to do a lot w the head to get more hp.

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The A motor I built for my 320 pickup was a lot of fun, and very powerful for an A12. The bottom end was basically stock, and the round port head was very minimally modified, but it did have a large cam and good valve springs, performance valve job, etc. It made about 100hp and revved as much as 32/36 allowed. I also lightened the flywheel a bit.

 

One of the biggest increases in power came from the intake manifold. I took a stock intake and cut the whole bowl out, well, about 3/4 of it actually. I then machined a bowl section out of a DGV conversion manifold for a 240Z (which had the DGV mounting pattern in it much more volume) to fit in the area I machined out of the stock intake. With about an hour of TIG welding and 20 minutes with a porting tool, I had the bowl smoothed out. The resulting manifold had about double the intake bowl volume. That made a huge difference in its ability to rev.

 

I wish I had pics of that intake.

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Take the head apart and port the fuck out of it. Get harbour freight grinder. Then buy a cam and valve springs.. should make a big difference. 15 more hp in a gutted 1500 pound car is signifigant. If the car is properly caged skin all inner metal out if the car. Weight is ur enemy

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So as someone who has been racing an A-series powered car since 1989 I'll chime in.

 

First off 50whp is 10 more than stock so pretty good for an ITC car.

 

$700 is more than enough to get some more out of the car. You can as mentioned above probably get 15-20 more horsepower out of the current motor.

 

You can port the existing head (I did mine using a dremel), the valve seats protrude into the port 1-2mm, just getting them flush with the port wall makes a big difference. Additionally you can smooth the area around the valve guide, after that just gasket match the intake.

 

Delta cams does regrinds for something silly like $75-$100. Their 278 grind is 278 duration with .420 valve lift, you won't have to notch the pistons with this cam. Lifters are around $50 from Rockauto. You'll need valves springs, Isky has them. I have a used set I'd let go cheap.

 

Order a GX .8mm head gasket off eBay, $75 and it will up the compression a bit compared to the standard 1.2mm gasket.

 

You can use a Sentra radiator, I use one in my 1200 coupe.

 

3.90 rear gear is waaaay tall, also get rid of the rancid welded diff, it's slowing the car down. You end up with less than optimal alignment settings to get the thing to turn. Get a 4.11 diff.

 

I use Hoosier Vintage TD-R tires 20.5 x 6 x 13, they are only 11lbs per tire and lower the gearing quite a bit over the normal 185/60-13s. John Berget tire sometimes has them. They are bias ply but it's not an issue. As your grandson is a kart driver he's got plenty of experience on bias ply tires.

 

The website Datsuncherry.ch has downloadable Nissan tuning manuals, click on brochures and scroll towards the bottom.

 

If you want PM me and I'll give you my phone number and we can talk more. I'm in Vegas. I also have some used parts that might work for you.

 

Here are some numbers just as an FYI

 

My A12GX motor that was stock other than Keihin 39mm flat slide carbs (came off a D-Sports Racer) made 73whp at 7800 rpm and lasted 8 seasons and cost me $800 to build. The same motor with a more aggressive cam that made 80whp lasted all 6 races as it was revved to 8600 rpm.

My A15 with 11.86 comp, Keihin carbs, Delta 278 cam, ported head, 37/30mm SI tapered valves made 99whp at 8200rpm and lasted 5 seasons before the head gasket went (it got way hot) I spent $2,809 on it. I'm building a new one and it will have around 100whp. I learned a bunch building the first one so I'll only have around $1,200 in it.

 

A-series cars can made to go well. On my local track car, 3.4 mile 22 turns, I'm something like 8-9 seconds slower than the Spec Miata lap record (national level car) as bad as that sounds I'm still run with mid pack local Spec Miatas. Granted I'm driving the car like an animal. Check the post on here "I'm thinking the handling still needs work" and you see what I mean. I'm in the red 1200 coupe just ahead of the camera car. You can also check a coupe of videos on YouTube search Scuderia Pokey, there are two videos and these are with the 80hp motor. As he has Karting experience I'd expect your grandson to be able to get the most out of the car.

 

Tom.

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Scooter if you reverse the words in the first part of the sentence it's really funny and even less appropriate for family hour.

 

When you own a car for 34 years and race it for 29 years you pick up a few things.

 

I forgot to mention that you can check with Peter Zekert as he may have some goodies. Check his website for contact info.

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Porting the "fuck" out of anything rarely yields beneficial results. Infact, oftebs times when you add material to intake runners you can produce more power by increasing the air velocity. I've seen this true at least once in real life, with my own customer.

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Porting the "fuck" out of anything rarely yields beneficial results. Infact, oftebs times when you add material to intake runners you can produce more power by increasing the air velocity. I've seen this true at least once in real life, with my own customer.

I have never heard this before, Dyno numbers?

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