The L92 that was swapped into my 67 Tempest broke the #7 piston with less than 2000 miles and while it is apart I might as well stroke it. That said, the engine was already bored to 4.070 and had a TSP 229/236 .629"/615" 112 LS cam. Since I am already out the money initially spent on the engine, I would like to reuse as much as I can and I have searched for hours and can't seem to find the answers to my questions.

So my first question is what kind of power should I expect out of the TSP cam in a 416 with stock heads that have had some mild porting or is it way too small for this displacement? For the short period of time the stock stroke engine stayed together, it had good driveability and plenty of power and I have seen similar combos making around 440 HP/420 TQ at the wheels. Mine made 368/400 but the fuel pump was going out when it was on the dyno and then it let go the day I got the fuel pump replaced so I don't know what it would have made. The car weighs about 3200 lbs and is a 6M with a 9" geared 3.70.

My next question is have there been any documented longevity issues with a 4.080 or larger bore in a 6.2? It already has a 4.070 bore and #7 looks pretty bad and we aren't sure .010 will clean up the damage.

Thanks in advance for any help.

 

First of all you do not want to use that camshaft with that displacement.
It is too small and certainly not suitable.
What are you doing with the vehicle?
I would fit something like a 236/244 114LSA +2 (my old LS 408 camshaft) This will drive quite nice on the street but will fall a bit flat after 6000rpm (12 degrees overlap)
If you want something healthy, a 242/250 113 LSA +4 would certainly get you moving and pull good up top also. (20 degrees overlap)

I don't know about the bore size but I do know builders usually only go 4.070 bore.
Anything over that doesn't leave enough meat in the bore on that block.
There are others who know about this subject more than me.
Hopefully they chime in for you.

 

The BTR 239/254 cam is the best yet I've seen proven on the dyno and at the track.

You'll be okay going 4.080 over on the bore.

It's a 418ci motor on board that has that bore and its proven as well.

 

If you have one hole worse than the others, just sleeve that hole. If you have to buy a set of pistons, it won’t matter anyway. Have your machine shop finish it where it cleans up and then have your pistons made.

 

No….the cam is NOT TOO SMALL to use in that engine.

It's not the best cam, in that it will leave a lot of power on the table....but it will run just fine!

That said....getting the intake duration in the mid-230's with the exhaust in the mid-240 degree range and keeping overlap in the in the 12 degree range give you another 40 (or so) HP to the wheels and will still have excellent drivability. So if you can pony up the bucks for a custom grind cam....do it!

I get my cams through Cam Motion....you might want to give them a call to see what they can do for ya.

BTW....that cam with the proper bolt-ons should easily get you in the 475hp/440tq range.....to the wheels.

KW

 

I made 468/450whp SAE with a 402, stock ls3 heads, stock intake and hooker exhaust manifolds.

226/242 on 117 cam. 0* overlap.

Stealthy.

 

Thanks everyone for all the feedback! The car is just meant to be a healthy resto-mod/pro-touring car that may someday see a strip or an autoX course, but will mainly be ripped around back roads and taken on the local cruise in circuit.

I will be reusing the stock LS3 intake until money allows for something better. I went with 1-3/4 to 1-7/8 stepped long-time headers with a full 3" exhaust with X-pipe and Spintech 6000 mufflers. Wish I had of gone with full 1-7/8 headers but I guess it is one in a long line of mistakes I have made with this car.

My NEW engine builder told me that a new sleeve was always an option but I like knowing if I have good options to build a solid reliable engine that will get flogged on occasion but not be abused.

I will call Cam Motion next week to see what they say since they come highly recommended.

 

It's not too small?
Have you checked the valve events in the calculator?
That camshaft would need to be on a 116LSA (at a minimum) to have half decent valve events for that engine size.
Otherwise power will just drop off in the top end.
You need to aim for a 48-50 IVC and a 60 EVO in a 416.
That camshaft is way off.

The 236/244 114LSA+2 has suitable valve events and with 12 degrees of overlap, it will drive well.
You could even put it on a 115 LSA for a bit more carry in the top end.
A 238/246 114LSA +3 is another good option with 14 degrees of overlap.
242/250 113LSA +4 is also good if you want it a bit more aggressive.

 

That's right.
Your valve events are good.
If you are using smaller durations on big engines you need a wider LSA to compensate to ensure you hit the right targets.

 

If you're into an engine build for the cost of a stroker, why not spend the extra $289 to $450 for a new cam ideally matched to your new 416? I'm sure the TSP cam mentioned is a nice cam and will make power but its going to leave power on the table compared to a more ideal roughly 236/244 on a 114 etc. My 416 has a 237/245 on a 114 and I think most view that as something of a peanut cam for a 416. I like to slightly under cam in general - tends to make for a better driver in my experience. I explained to Darin Morgan of Reher-Morrison my set up and what I wanted. He spec'd exactly what i was looking for. I'd call Darin or other guru for a custom cam.

I definitely wouldn't go smaller than about 236/244 unless forced by budget. 242/25x would be getting near the biggest cam I'd be willing to run in a 416 with a good tune.

 

I agree.
The 236/244 would be the minimum i would use.
a 238/246 is a good compromise
242/250 would still drive good with a proper tune.

 

[QUOTE=99 Black Bird T/A;20242105]If you're into an engine build for the cost of a stroker, why not spend the extra $289 to $450 for a new cam ideally matched to your new 416? I'm sure the TSP cam mentioned is a nice cam and will make power but its going to leave power on the table compared to a more ideal roughly 236/244 on a 114 etc.

I originally wanted to try to get away without a new cam because the crank has already been ground down once, has some damage that polishing might not fix and has some questionable repairs already done at the reluctor ring, so a new crank was in order for peace of mind. Based off the information here, a new cam is in order. I have some people interested in the heads that I'm replacing and the rods. I'm sure the cam will get some interest too to help offset some of the cost.

 

Excellent point! Yes, I would image you'll get some good interest in the TSP cam and that will help offset the cost of a custom spec'd new cam.

 

Like I said.....NOT TOO SMALL.

I also said it wasn't optimal.

Damn dude....you sound like that cam is gonna break his engine or something. LOLOL!

KW

 

Damn dude, you sure know how to give the OP good advice by encouraging him to use a cam that is clearly not optimal for the setup. LOL

 

I made that with a stock heads cam LS3 M6 in 2 different set ups. Its all in the combo.

 

M6 or auto trans? With an M6 a 12 deg. overlap camshaft will require a good tune to eliminate bucking and have good driveability. With 20 deg. overlap you'll need a Superman tune.

 

GrmSierra, thinking about this some more and want to add this. With drifting and hold high rpm in the 7,000 rpm or so range for a good while compared to drag racing, I would definitely go with a custom cam grind.

Key reason the cam guru can pick an ideal cam lobe that will be stable at that rpm with your valve train and not excessively hard on the valve springs. That should help with reliability.

A lot of the off the shelf cams have harsher cam lobes that are very fast and make excellent power but are probably a little more drag race oriented.

Best wishes with the project.

 

HP on 416’s seem to drop like a rock after 6000 with a stock ls3 intake btw

 

I will go with a better intake later once more cash is available. This all happened while I'm in the middle of selling my house, buying another one and doing some updates to the new home. To make matters worse, the shady mechanic that sold me the engine and put it in also damaged my car while it was at his shop so I am also in the middle of an insurance battle.