347 Build With Mechanical Roller Camshaft

[TRQ]

Hello,

I just finished re-building my 347 engine (ESP-B14003030)+(AFR-1450) and I’m not getting the engine to run as I excepted… So I’m looking around for some answers and what might went wrong.


During the rebuild, I have switched my camshaft from hydraulic roller to solid mechanical roller (CRN-448031),

but still using the same distributor steel gear that came with it originally (MSD-8598), according to Crane Cam catalog the new cam would works fine with bronze or steel gears…

Does the distributor gear ratio play a major role in making power? And if doesn’t should I stick to the ratio recommended by Crane cam.


Also, for the head gasket, I used a Cometic (C5512-030) but noticing some water leak by the headers after starting the engine, I just found out that Cometic make different head gasket for the engines with AFR heads, gasket # (C5910-051).

What is the different between those head gasket and is that a possible reason why engine not making the power it should!!!



As you can see from the gasket part numbers, I’m planning to go for a higher gasket thickness because some people suggested that I have too much compression for this engine and that’s the reason I can’t increase timing to achieve more power.

Please share your thoughts as I’m really lost as this point and not sure where to start.

Thanks

 

[CarMichael Angelo]

Soooo,...many things here.

What exactly does "Not making the power it should!!!" mean?

There is no "ratio" difference between cam gears on the distributor. It is an alloy difference. Mech roller cams are typically made of billet steel and the gear on the cam is way more "hard" than one on a conventional camshaft. The hardness of a billet cam gear requires a "softer" (in the case of the bronze gear) or a compatible one (steel) that wont be destroyed by the cam shaft as a standard cast iron distributor gear would.

As for the HG leak,...if there is a Cometic PN specific to your head, that's what you shoulda got. It's more than likely a leaking water passage that the gasket you are using did not cover adequately. Regardless, Cometic MLS gaskets are notorious for leaking even when they are correct.

Running bad is one thing, not make the power it should is relative.

The cam could be too big, installed incorrectly, or just totally wrong for your combination,.....All are contributing factors as to why it isn't running right. (If that's the case) I'm assuming that you changed lifters, and are using solid roller lifters with your solid roller cam, and not the hyd roller lifters that were in the motor before?

** Just looked at your cam specs,.....that is a "motor" cam, and is one the big side for a street car....what are you doing with this engine again?

 

[RangerJoe]

Good advice. What about valve springs? Did those get changed too?

Joe

 

[TRQ]

Thanks for the detailed advice,

When I said "it is not making the power it should" I meant it is only making 390-420 hp, whereas I was making 430 with my hydraulic camshaft... Yet I would say engine working fine.
My main goal when switching to mechanical roller was to gain more power.

Springs and lifters were changed to work with the mechanical cam, and it does have an eagle stroker.

I can't tell if the cam is installed correctly or not, but it was not checked with degree wheel, not sure if that could be another reason.

Answering your question about the build, I'm trying to end with weekend street / strip car...

 

[TOOLOW91]

Thats alot of cam. What rear end gear ? What trans ? What tire size? Just trying to get a better feel for the characteristics of the car and what rpm it lives at.

 

[CarMichael Angelo]

Thanks for the detailed advice,

When I said "it is not making the power it should" I meant it is only making 390-420 hp, whereas I was making 430 with my hydraulic camshaft... Yet I would say engine working fine.
My main goal when switching to mechanical roller was to gain more power.

Springs and lifters were changed to work with the mechanical cam, and it does have an eagle stroker.

I can't tell if the cam is installed correctly or not, but it was not checked with degree wheel, not sure if that could be another reason.

Answering your question about the build, I'm trying to end with weekend street / strip car...

Ok then, and to verify...the power you said it was making was determined on a dyno?...and the new power figure has been determined on the same dyno?
Typically, the mech roller would/should make more power. If the grind specs are close to the one it replaced there may not be that much power left on the table. Other than stating that you have AFR heads, you didn't say which pair.

The only thing I can say is that if the car wasn't compared on the same dyno, in the same air quality, things could change significantly just by that fact.

 

[RangerJoe]

I have never ran a mech. in my car, but from most of what I have seen, it looks like most mech. rollers need to be turned more rpm to take advantage of their design. hydraulic cams have come a long way and make great power these days. may be hard to top it using the button dyno.

Joe

 

[TOOLOW91]

I have never ran a mech. in my car, but from most of what I have seen, it looks like most mech. rollers need to be turned more rpm to take advantage of their design. hydraulic cams have come a long way and make great power these days. may be hard to top it using the button dyno.

Joe

This is why I asked about rear end gear, transmission etc to get an idea of how high he's actually turning the motor .




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[CarMichael Angelo]

Brand:Crane Cams

Manufacturer's Part Number:448031

Part Type:Camshafts

Product Line:Crane Mechanical Roller Camshafts

Summit Racing Part Number:CRN-448031


UPC:021174047127

Cam Style:Mechanical roller tappet

Basic Operating RPM Range:3,200-7,000

Intake Duration at 050 inch Lift:244

Exhaust Duration at 050 inch Lift:252

Duration at 050 inch Lift:244 int./252 exh.

Advertised Intake Duration:284

Advertised Exhaust Duration:292

Advertised Duration:284 int./292 exh.

Intake Valve Lift with Factory Rocker Arm Ratio:0.619 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio:0.640 in.

Valve Lift with Factory Rocker Arm Ratio:0.619 int./0.640 exh.

Lobe Separation (degrees):110

Intake Valve Lash:0.022 in.

Exhaust Valve Lash:0.022 in.

Computer-Controlled Compatible:No

Grind Number:TR-244/3867-2S-10

Valve Springs Required:Yes

Quantity:Sold individually.

Notes:Requires a steel or aluminum-bronze distributor drive gear, 7/16-20 x 1-1/4 in. grade 8 cam gear bolt, and hardened washer. Also for use with 302 and 351 SVO engines. 10.5 to 12.0 compression ratio advised.

In-Store Pickup:Choose In-store pick-up (OH, GA, NV) on our web site

Yeah,....That too. I'll bet the power band is significantly above where the previous camshaft was making it's power.

 

[TOOLOW91]

Brand:Crane Cams

Manufacturer's Part Number:448031

Part Type:Camshafts

Product Line:Crane Mechanical Roller Camshafts

Summit Racing Part Number:CRN-448031


UPC:021174047127

Cam Style:Mechanical roller tappet

Basic Operating RPM Range:3,200-7,000

Intake Duration at 050 inch Lift:244

Exhaust Duration at 050 inch Lift:252

Duration at 050 inch Lift:244 int./252 exh.

Advertised Intake Duration:284

Advertised Exhaust Duration:292

Advertised Duration:284 int./292 exh.

Intake Valve Lift with Factory Rocker Arm Ratio:0.619 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio:0.640 in.

Valve Lift with Factory Rocker Arm Ratio:0.619 int./0.640 exh.

Lobe Separation (degrees):110

Intake Valve Lash:0.022 in.

Exhaust Valve Lash:0.022 in.

Computer-Controlled Compatible:No

Grind Number:TR-244/3867-2S-10

Valve Springs Required:Yes

Quantity:Sold individually.

Notes:Requires a steel or aluminum-bronze distributor drive gear, 7/16-20 x 1-1/4 in. grade 8 cam gear bolt, and hardened washer. Also for use with 302 and 351 SVO engines. 10.5 to 12.0 compression ratio advised.

In-Store Pickup:Choose In-store pick-up (OH, GA, NV) on our web site

Yeah,....That too. I'll bet the power band is significantly above where the previous camshaft was making it's power.

My thoughts exactly


Sent from my iPhone using Tapatalk

 

[mikestang63]

Holy where did my bottom end go Batman

 

[TRQ]

Yep, That’s the cam I’m running…

And yes the car was tested on the same Dyno, relatively same conditions.

To have a better idea, here the numbers with comparison to the old hydraulic cam,

Hydr cam: 450 HP & 390 TQ (timing 30) pump gas

Mech. Cam: 429 HP & 438 TQ (timing 20) with pump gas

We weren’t able to increase the timing more, and it was actually making less power with the more timing so some guys suggested that we have high compression and we need to run it with race fuel… so we tried it with the C-16 (might not be the right choice, but is only available option at that time), same results as the pump gas, no change in numbers except getting richer.


Here are some more details and answers.

AFR heads: part# 1450

58 CC chamber

Intake runners: 205

Exhaust runners: 70


347 Eagle stoker: part# B14003030

Bore: 3.040 in

Internal balance


Rear ratio is 3.73

Stock Mustang 16” wheels and tires

RPM: 6000

Quick Fuel Q-Series 4-Barrel Carburetors BDQ-750, part# BDQ-750

Intake: Edelbrock Victor Jr. part# 2921

 

[CarMichael Angelo]

Yep, That’s the cam I’m running…

And yes the car was tested on the same Dyno, relatively same conditions.

To have a better idea, here the numbers with comparison to the old hydraulic cam,

Hydr cam: 450 HP & 390 TQ (timing 30) pump gas

Mech. Cam: 429 HP & 438 TQ (timing 20) with pump gas

We weren’t able to increase the timing more, and it was actually making less power with the more timing so some guys suggested that we have high compression and we need to run it with race fuel… so we tried it with the C-16 (might not be the right choice, but is only available option at that time), same results as the pump gas, no change in numbers except getting richer.


Here are some more details and answers.

AFR heads: part# 1450

58 CC chamber

Intake runners: 205

Exhaust runners: 70


347 Eagle stoker: part# B14003030

Bore: 3.040 in

Internal balance


Rear ratio is 3.73

Stock Mustang 16” wheels and tires

RPM: 6000

Quick Fuel Q-Series 4-Barrel Carburetors BDQ-750, part# BDQ-750

Intake: Edelbrock Victor Jr. part# 2921

Ok then, this is getting easier.

Firstly, C-16 is a nitrous fuel. Unless your "high compression" is in excess of 12:1 it is partly to blame, especially if the other set of pulls were made on pump gas.
That is a fact. C-16 is a slower burning fuel. It's used to control detonation on really high cylinder pressures that are typical when guys have a buttload of nitrous (500+ hp) being pounded in on top of that compression.Not only does C16 burn slower, it burns cooler as well. Using it was just WRONG.

Now take ten degrees total timing out of the combination, even when the total timing before was typically what most consider here not enough, and I'd say those two things make up 80%-90% of your problem.

The other 10-20% is your RPM limit with that cam. You can see from the specs listed that the mfg shows a power band to 7200 RPM and you are shutting the engine down at 6,000. It is a 347,...piston speeds are already raging,...so maybe the engine only likes 6k RPM,...but until you get all things equal.....

By your own choices, (or that of your Dyno guy) you stopping the motor from making power that it probably could have made by setting a street friendly shift point, restricting the timing to 20 degrees total and using a 17:1 CR rated race gas. (It's a wonder it even ran)

Your Dyno guy sounds like he needs to spend more time w/ racers, and take some remedial engine tuning classes.

How exactly is it that you couldn't get more timing than 20 degrees? All you have to do is turn the distributor clockwise. The only way for you not to be able get more timing is if the distributor was reinstalled after the cam swap at a point where it hits the water neck that prevents it from turning.

Dyno dude also shoulda known that C-16 wasn't gonna help your numbers as well.. The fact that you were able to get away w/ pump gas before on the old combo and this new one w/o detonation tells me that you don't have "high compression". You've seen your assembled short block w/o heads right? You'd have to have a significant domes on the pistons hanging out of the deck to have any compression more than 10-10.5:1 CR. If they were flat tops,..........On a 347, even w/ a stroker crank, and a 58 cc chamber, a flat top piston yields a 10.7:1 CR
At the most, you shoulda been using 100 octane (Again unless you have 12.5:1 + compression already) and even then, something slighty higher than that, NOT C-16. There are actually instances where guys use the fuel to SLOW THEIR CARS DOWN at the track.

Lastly,....Dude! Look at the TQ difference between the two engine combos!!!!

For a cam to make 50 more ft lbs TQ and the tune still be wrong.........somethin' ain't right.

If the numbers are right, then the advice is wrong.

Fix the timing. (Probably a distributor problem) Drain the gas, and get some fresh pump premium.
and when you get the timing figured out........Take it to a different dyno guy (Cause the one you've been using will be in training at UTI)

 

[HotFox]

For comparison I'm running a 331, FTI solid roller, AFR 205, 10.5:1, long tubes x pipe 3", super victor, 780cfm, pump gas with splash of 110 racing I strive for 95-97octane. it likes 38 degrees of timing. Making 470 rwhp 380 ftlbs, but as the dyno guy said that is the most stout 331 he has seen. Beat and 347 any many 408 he has seen come through his shop.

 

[A5literMan]

Would be even better if we saw a dyno graph. Are you 100% positive you don't have a vacuum leak? No reason that motor should be running only 20* of timing. Also if your stated numbers are from a chassis dyno that's a stout little motor. Something is off if you picked up 50 ft lbs torque and dropped 20hp. I would guess timing,fuel,and not enough rpms. Usually between a Hyd roller vs a mechanical you won't see much difference in the lower to mid rpms. The mechanical should really shine in that 6-7k range especially that particular setup. If you're shutting it down at 6k...why? The only other thing I can think of is you have fairly low compression and the cam is just the wrong choice and/or the valve springs aren't good enough. Who picked the cam? And how did they choice it?

 

[mikestang63]

FWIW, I ran in the 90's a 347 with 11.5 to 1 compresson and made 455rwhp on PUMP GAS with a splash of VP 110- that was with a .655 solid lifter cam. I could and have driven that car over 40 miles each way to Moroso ( now PBIR) with no overheating, or hiccups. As Mike said, you have a combination of misatched parts and a questionable tuner

 

[TRQ]

Thanks Mike for all the detailed info… I guess I should’ve discuused this build with you long time ago J

You giving more sense than the guys who have their hands on it.


I totally agree with you that we can’t blame the C-16 alone for this since we tried it with pump gas before.

For the timing, we caould actually increase the timing to 30, but the power drops about 30 HP/30 TQ… it made the most power at 20 timing.

You mentioned that ditributor might be installed wrong… I’m using the same distributor gear from the hydr camshaft, could that be a reason? Is there any ratio or different degrees to those gears!!

I used the same gear because Crane Cam notes says that it can be used with bronze or steel gear.


The car is set for 7000 RPM, but the guy only run to 6000 on the dyno, I guess he was afraid to hurt the eninge since it wasn’t giving the number he expected.


Speaking about engine compression again, as many people bring this to the table, the compression I have is calculated to be about 11:1 which is good for the camshaft.

But sharing little history about this engine that might mess my whole calculation…

The reason of me taking this engine apart, other than swapping the to the new cam combo, is that I had a head gasket issue… water was leaking and did some damage to the head facing, made some kinda cavities on the surface (CC is ok no damage)

So I had to send the heads to a machine shop to fix, they fixed the heads and all good… but now me thinking of it, I guess I might be getting a wrong calculation unless machine shops normally work on keeping things, especially CC, in the original dimensions.

My pistons are +5, again some people suggested that I might have over compression and suggested to go with Q-16 this time… not sure how accurate is that.
and how about having low compression, any posssiblity!!

I'll try to get a picture of the dyno sheet so you guys have better idea of how it acted...

 

[cleanLX]

anyone else think .022 lash is a little loose?
it's making 50tq more... tq is usually really hard to come by.
i may have missed it but is this and EFI car or a carb car? spout out when setting timing?

 

[CarMichael Angelo]

anyone else think .022 lash is a little loose?
it's making 50tq more... tq is usually really hard to come by.
i may have missed it but is this and EFI car or a carb car? spout out when setting timing?

It's a car'b car and yes, he could probably tighten it up a little ( like .002-.005) and I'd say there's no such thing as a spout.

 

[HotFox]

Yes I agree on the torque. Love to see the dyno sheet. but there is something really wrong with only 20 degree of timing.