Cam regrind information

[cpearce]

I recently cam across an almost brand new Bullet solid roller cam for sale for $150. I would not have considered used under other circumstances, however cam looks to be like new and is similar in spec to what I was thinking of using in next engine. The application is race only, 372ci, w2 or Indy 360-2 heads, r3 block, compression around 12.5, and solid roller cam, pro dominator tunnel ram, 2 Quick Fuel 750's.

I have attached cam card to show grind. My concern lies with the longer duration on exhaust, I would prefer a single pattern or much smaller split on duration while using heads with a very good exhaust port. Could the exhaust duration be reduced much with regrind? Today I will be calling Bullet and Oregon cams for info, just looking to get info and experiences from FABO friends as well. Thanks everyone.

 

[RustyRatRod]

I would run a good used hydraulic or solid roller in a minute! They don't wear specific like flat tappets and if everything was right with them, they hardly wear at all. Plus, you can have them reground. Oregon cam grinders has done a couple for me and I like the quality.

 

[cpearce]

I would run a good used hydraulic or solid roller in a minute! They don't wear specific like flat tappets and if everything was right with them, they hardly wear at all. Plus, you can have them reground. Oregon cam grinders has done a couple for me and I like the quality.

Yeah, I thought it looked pretty good.

 

[rumblefish360]

The longer exhaust is primarily used for poorer flowing exhaust ports. Gains have been found with split cams even with good exhaust.

In other words, I would t worry about is. Unless there is a need to scientificly make this as perfect as possible?

IMO, I think a phone call to bullet with exactly what you plan to use would be a good move and ask them if they have a better cam for this application and the pros and cons of the split duration on there cam.

 

[rumblefish360]

Oh! PS...

I’d run it in a second flat if it met the rpm range of what I was trying to do. I’ll assume you already have the fully max ported W2’s with the Pro Dominator tunnel ram. As well as all the rest of the matching gear from stem to stern.

Does [email protected] in a 372 cube engine meet the rpm range requirements? The extra exhaust duration helps extend the rpm range up top a little bit. This could have some real top end pop!

 

[cpearce]

Oh! PS...

I’d run it in a second flat if it met the rpm range of what I was trying to do. I’ll assume you already have the fully max ported W2’s with the Pro Dominator tunnel ram. As well as all the rest of the matching gear from stem to stern.

Does [email protected] in a 372 cube engine meet the rpm range requirements? The extra exhaust duration helps extend the rpm range up top a little bit. This could have some real top end pop!

Hello Rumble,

I have the block, heads, tunnel ram, carbs, crank, pan, bunch of small parts so far. My engines take me a couple years to do as I can afford it. I believe in buying good parts the first time so it takes me a little longer. The heads are bare w2 castings not yet ported. Not sure, I might use the Indy 360-2 this time to save weight and keep W2 heads as spares for my 408.

 

[rumblefish360]

Hey my Garden State brother! How’s the other side of the river today?

I also have to take (way to much) time in building my stuff. I have a goal! And it will be a little pricey vs. the regular hp mills I put together. I feel your pain! Where is my winning lotto ticket?!?!?!

You have some good parts on hand. Sounds like my stash.

Make that plan and stick to it. You know not sticking to it will cost a lot of money.
Make that call to ultra dyne!

 

[yellow rose]

I recently cam across an almost brand new Bullet solid roller cam for sale for $150. I would not have considered used under other circumstances, however cam looks to be like new and is similar in spec to what I was thinking of using in next engine. The application is race only, 372ci, w2 or Indy 360-2 heads, r3 block, compression around 12.5, and solid roller cam, pro dominator tunnel ram, 2 Quick Fuel 750's.

I have attached cam card to show grind. My concern lies with the longer duration on exhaust, I would prefer a single pattern or much smaller split on duration while using heads with a very good exhaust port. Could the exhaust duration be reduced much with regrind? Today I will be calling Bullet and Oregon cams for info, just looking to get info and experiences from FABO friends as well. Thanks everyone.

View attachment 1715142268

Cam grinders LOVE dual pattern cams because they are easier to sell. On speedtalk.com there was a discussion and one cam grinder admitted why he did it. They add exhaust duration so they can use less intake duration, and the extra exhaust will make the cam over rev, or hold on past peak HP longer. They think that's tricky but I don't care for it. With that head there is no reason why you can't run [email protected] on the intake and [email protected] on the exhaust. It will make the engine fall off past peak HP much quicker, but it will out more area under the power curve.


All that said... I'd run it since you have it. Depending on the core, you have no idea how deep the heat treat is. A regrind of the same lobe, or a very minor change of the lobe and you probably won't break through the heat treat. But a big LSA change or anything else the probability is you will grind through the heat treat. Then you will see the lobe track up.

 

[cpearce]

Cam grinders LOVE dual pattern cams because they are easier to sell. On speedtalk.com there was a discussion and one cam grinder admitted why he did it. They add exhaust duration so they can use less intake duration, and the extra exhaust will make the cam over rev, or hold on past peak HP longer. They think that's tricky but I don't care for it. With that head there is no reason why you can't run [email protected] on the intake and [email protected] on the exhaust. It will make the engine fall off past peak HP much quicker, but it will out more area under the power curve.


All that said... I'd run it since you have it. Depending on the core, you have no idea how deep the heat treat is. A regrind of the same lobe, or a very minor change of the lobe and you probably won't break through the heat treat. But a big LSA change or anything else the probability is you will grind through the heat treat. Then you will see the lobe track up.

I actually have not purchased it yet, doing research first. Just spoke with Mark at Bullet, he doesn't feel it will overscavenge the exhaust with that extra exhaust duration. He feels this should work well in that combo at 4500-7500 plus with proper valve springs and pressure over the nose at about 700lbs. He recommnds 1.6 rockers and a tall intalled height to get proper spring compression to keep harmonics out of springs. Small changes could be made on either or both lobes to get split closer.

 

[MOPAROFFICIAL]

That sucka gonna sing.
Run it.

 

[cpearce]

Thanks for input fellas, I finished the deal. The cam is on its way! Should make for a lively little package.

 

[rumblefish360]

Excellent! Looking forward to it all.