All Small Six Cam for early block?

[ShaneB]

Hey folks... I am pretty new to these motors and just trying to learn and pull a plan together. The motor I have is a newly rebuilt 170 4 bearing motor.

Question is... does anyone make a cam for those? I see the Clay Smith cams say 144-170-200-250... but my understanding is that the cam is NOT the same in the early block and the later block. Is that correct?

Yes..... I have the book.... no... there is not much information at all about the early motors in it.

 

[aussie7mains]

Hey folks... I am pretty new to these motors and just trying to learn and pull a plan together. The motor I have is a newly rebuilt 170 4 bearing motor.

Question is... does anyone make a cam for those? I see the Clay Smith cams say 144-170-200-250... but my understanding is that the cam is NOT the same in the early block and the later block. Is that correct?

Yes..... I have the book.... no... there is not much information at all about the early motors in it.

From my recollection the only difference was in the cutouts to clear the con rods. The aftermarket cams seem to be all made on the same casting, which is setup for 250ci engines. The 250, having the longest stroke has the largest cutouts, so it should be OK in any of the smaller engines. I would however give carefull consideration on your cam choice, as the 170 doesnt have a lot of toque, you wouldnt want to loose too much going to a long duration cam profile, especially when constrained by the "log head'. And, this is especaily true if you have a slushie!

 

[awasson]

Also, make sure the 170 has the oil passages for hydraulic lifters. If not, you'll definitely need to go with solid lifters. If it was running fine with hydraulics, you can just ignore this.

 

[ShaneB]

Also, make sure the 170 has the oil passages for hydraulic lifters. If not, you'll definitely need to go with solid lifters. If it was running fine with hydraulics, you can just ignore this.

Thanks! I appreciate that. It’s a little cobbled together, but it’s a C1 block so I assume it’s solid lifter. Haven’t checked it yet. For sure adjustable rockers. But when I pull the head I’ll fish one out and check!

As for cam selection…. That’s yet to come. I am going to go to 2bbl EFI pretty quick with an adapter. And then probably modify a large log head to direct mount.

In the end what I’d really like is to put a Paxton SN60 setup on it blown through the 2bbl sniper.

Disclaimer…. No…. It won’t be all that fast. Ha! But it’ll sound awesome. ha! And if I wear the 170 out or break it… I’ll build a 200 or a 250 instead.

 

[aussie7mains]

Thanks! I appreciate that. It’s a little cobbled together, but it’s a C1 block so I assume it’s solid lifter. Haven’t checked it yet. For sure adjustable rockers. But when I pull the head I’ll fish one out and check!

As for cam selection…. That’s yet to come. I am going to go to 2bbl EFI pretty quick with an adapter. And then probably modify a large log head to direct mount.

In the end what I’d really like is to put a Paxton SN60 setup on it blown through the 2bbl sniper.

Disclaimer…. No…. It won’t be all that fast. Ha! But it’ll sound awesome. ha! And if I wear the 170 out or break it… I’ll build a 200 or a 250 instead.

One of the small toyota sc14 blowers would be better than a paxton type of thing. Far better response right of idle, would turn the 170 into a 250! You could do a single throat EFI as a draw through. If you draw through you get the benefit of the fuel vaporising upstream of the blower, this also seals the rotors better.

 

[awasson]

Thanks! I appreciate that. It’s a little cobbled together, but it’s a C1 block so I assume it’s solid lifter. Haven’t checked it yet. For sure adjustable rockers. But when I pull the head I’ll fish one out and check!

As for cam selection…. That’s yet to come. I am going to go to 2bbl EFI pretty quick with an adapter. And then probably modify a large log head to direct mount.

In the end what I’d really like is to put a Paxton SN60 setup on it blown through the 2bbl sniper.

Disclaimer…. No…. It won’t be all that fast. Ha! But it’ll sound awesome. ha! And if I wear the 170 out or break it… I’ll build a 200 or a 250 instead.

Cool! Give the guys at Clay Smith a call. They're good at answering the phone and you can tell them about the engine and your plans and they will steer you in the right direction. Last time I called, I talked to the guy who designed the H-6474-0-B camshaft I'm running and we covered a lot of ground on tuning carburetion and timing.

I'm running a 2V Weber on the small log 200 and it is surprising how well it pulls considering the performance obstacles a small log head, valves and valve springs presents. It does sound pretty awesome too.

View media item 329

 

[Frank]

You could do a single throat EFI as a draw through.

I am going to go to 2bbl EFI pretty quick with an adapter.

The 2V sniper will run but it's far too big for the engine. There will be no power gain over the 1 barrel Sniper in NA form on the log intake.
A 170 CID engine must turn 14,740 rpms to breathe all of the 2V Sniper. At 5000 rpm WOT the 2V will be at 28% of it's capacity.

 

[ShaneB]

Yup. The nice thing about EFI is that they adjust to that much better than a carb.the 2bbl should offer some better distribution to all6 (though not perfect) and it will be substantially cheaper. You can find them used at a good savings and the 1100 hardly ever comes up used. It also has some other limitations that I don’t love. Great solution if all you want is to clean up the fuel side with EFI. But doesn’t leave much room to grow.

The sc14s are pretty cheap… but… they are terribly ugly and of course not anywhere close to period correct.

 

[ShaneB]

Cool! Give the guys at Clay Smith a call. They're good at answering the phone and you can tell them about the engine and your plans and they will steer you in the right direction. Last time I called, I talked to the guy who designed the H-6474-0-B camshaft I'm running and we covered a lot of ground on tuning carburetion and timing.

I'm running a 2V Weber on the small log 200 and it is surprising how well it pulls considering the performance obstacles a small log head, valves and valve springs presents. It does sound pretty awesome too.

View media item 329

Sounds great!