6Time's Stroker build.... Round 1

[6TIME]

Hey guys, I've been lurking for quite some time but haven't found the time till now to post some pics up. Here's my build list for Round one of my 87 octane budget stroker....

93 HO block thermal cleaned, shot peened, 0 decked, bored and honed on Rottler CNC.
4cw Short shout Crank turned 20/20
707 Rods, polished beams, shot peened, and Arp bolts.
Sealed Power 677ACP .030 pistons Dished to 26cc.
Clevite 77 Main and rod bearings
Ported 7120 head with LS1 beehive springs, LS valves/hardware, bronze guide liners, 3 angle Serdi grind. 65cc chambers
Rocker pedestals cut .350 for screw in Comp 4504 studs with Comp 4842 pushrod guideplates
Ford 240/300 ductile rockers 1.6 ratio 3/8 stud.
Lunati 63500 Voodoo cam with a set of Mopar lifters.
Rollmaster double roller timing set.
Hardened 5/16 9.625"ish pushrods.
Mopar Perf/Victor Reniz 54249 .043" MLS head gasket

My Compression (8.6:1)came up a bit lower than I expected The LS valves offer some extra chamber volume due to their tuliped underhead shape. I had a hard time estimating how much volume I'd gain after the grind was complete ...Oh well I ran it.... here's some pics.



4Cw Crank all prettied up


Side view


677's hangin on the 707 Rods.


Crank and rods all torqued up.


I wasn't planning on the Main girdle, but found one along with the Main bolts at the local pick and pull for 5 bucks


Top view. I didn't take closeups of the notches/bevel in put on the top of the cylinders, but you can kinda see them in this pic. They match up with the chamber walls adjacent to the valves providing a smooth flow transition from the side of the valve to the cylinder wall. I bolted up the head to the bare block and scribed the mismatch then used a carbide burr to correct it. I did this in every cylinder until i could feel a smooth transition between the chamber and the cylinder.


26cc Piston dish...Thanks Oletshot.


Lunati 63500 installed straight up. Had some issues with the Rollmaster timing set giving me the right phasing. So I had to jockey keyway positions around until I got it at zero....wierd. I also degreed a replacement timing set I had laying around and it had about 12 deg retard. Note to self if you run a aftermarket cam with a stock replacement timing set......



Carbide treatment....


LS valves have a 8mm stem so minimal work is required to adapt.
Intakes were 2.00 I had them cut down to 1.95" and kept the exhausts at the stock 1.55" diameter.


Similarities between 4.0 and LS valves...


Valvetrain hardware going together...


Bottom view shows the extra volume that the LS valves add to the chamber...


Valvetrain geometry check! Dinky spring installed for running a tip pattern. Lucky! Came up really close on the first guess at pushrod length.


Had some 1.75 ratio Crane roller rockers for a GM 250 I-6 they would also work but needed different pushrod length...
I'll stay with 1.6 till The motor is dialed....



Head bolted up, Valvetrain put together! Polylocks set the lash at 1/2 turn past zero lash. The Ford pieces fit nicely.




A fresh coat of black and silver urethane, and it's Goin in! A BBC damper bolt works perfect for this motor and it has an extra tall head to make turning the motor over easier:)
I probably forgot something somewhere... but at least I finally got some pics up! More to come

[GoMopar440]

Very nice play by play with the pics. How much longer till you get it fired up?

I hope my build goes this smooth when I'm able to start on it (probably not till after the spring semester is over ).

[6TIME]

This motor was put together a while ago. Cam break in went good and valvetrain was nice and quiet too. The motor ran excellent! It pulled pretty good but seemed a bit soggy under 2500rpm. I wasn't quite sure if it was the nature of the cam or the lower than ideal compression that I was running (8.6SCR/7.4DCR)? Cranking psi 155 -+5psi. I also encountered some interesting vibration issues that were pointing towards the bottom end harmonics, balance job, or clutch issues. The shaking wasn't violent by any means, but it was definitely noticeable at anything above 3200rpm. The motor ran very smooth under the 3200 rpm mark. I drove it daily and towed with it frequently. I racked up about 26k miles on it in about a year and a few months of driving. I had the tranny out a few times to check flywheel runout and had it and the pressure plate rechecked for balance. Everything came out fine. It was definitely a harmonic or bottom end imbalance. I also swapped dampers with no change. It bothered me enough that I didn't like running it past that 3200 mark...so I finally took the Jeep back out of service and yanked the motor out of curiosity to see what was going on. Turned out to be good timing anyways, because my cam bearings were almost wore down through the lead which was odd because my oil pressure was not noticeably low The cam looked great, the lobes were nice and smooth with no pitting visible anywhere. Pistons looked normal with minimal skirt wear. Mains looked barely used and the rods looked fine. So I tore the motor down inspecting everything and found no issues except for the dead cam bearings. The bottom end parts all got sent back to the machine shop for evaluation on the balancing machine. Everything was re-weighed, re-balanced and or spin balanced and the crank got magged again looking for a crack...... Nothing. I began to question my setup with the 4cw crank because I was running out of options. I did many searches finding no support on 4cw cranks having vibe problems at all. I did know that a fully counterweighted crank would run smoother than a crank with less counterweights. But could this be the source of my vibration? I have no idea. I did have a 12cw crank so my machinist and I both agreed to run it and find out. Since nothing else would change in the bottom end except the crankshaft I would know for sure, the differences between the light and heavy cranks. Anybody had any experiences with running both crankshafts?

[Muad'Dib]

This motor was put together a while ago. Cam break in went good and valvetrain was nice and quiet too. The motor ran excellent! It pulled pretty good but seemed a bit soggy under 2500rpm. I wasn't quite sure if it was the nature of the cam or the lower than ideal compression that I was running (8.6SCR/7.4DCR)? Cranking psi 155 -+5psi. I also encountered some interesting vibration issues that were pointing towards the bottom end harmonics, balance job, or clutch issues. The shaking wasn't violent by any means, but it was definitely noticeable at anything above 3200rpm. The motor ran very smooth under the 3200 rpm mark. I drove it daily and towed with it frequently. I racked up about 26k miles on it in about a year and a few months of driving. I had the tranny out a few times to check flywheel runout and had it and the pressure plate rechecked for balance. Everything came out fine. It was definitely a harmonic or bottom end imbalance. I also swapped dampers with no change. It bothered me enough that I didn't like running it past that 3200 mark...so I finally took the Jeep back out of service and yanked the motor out of curiosity to see what was going on. Turned out to be good timing anyways, because my cam bearings were almost wore down through the lead which was odd because my oil pressure was not noticeably low The cam looked great, the lobes were nice and smooth with no pitting visible anywhere. Pistons looked normal with minimal skirt wear. Mains looked barely used and the rods looked fine. So I tore the motor down inspecting everything and found no issues except for the dead cam bearings. The bottom end parts all got sent back to the machine shop for evaluation on the balancing machine. Everything was re-weighed, re-balanced and or spin balanced and the crank got magged again looking for a crack...... Nothing. I began to question my setup with the 4cw crank because I was running out of options. I did many searches finding no support on 4cw cranks having vibe problems at all. I did know that a fully counterweighted crank would run smoother than a crank with less counterweights. But could this be the source of my vibration? I have no idea. I did have a 12cw crank so my machinist and I both agreed to run it and find out. Since nothing else would change in the bottom end except the crankshaft I would know for sure, the differences between the light and heavy cranks. Anybody had any experiences with running both crankshafts?

I know i have a 4cw in mine right now with no vibes at all except at idle... but this is because of the HD Motor Mounts im using.

[SilverXJ]

I have ran both the 12 and 4 and vibe wise I would not tell the difference. Sucks about your bearings, I know how that goes. Were yo using the stock cam retention method? Were the cam bearings just damaged at the bottom or all around?

Maybe check cam run out?

[6TIME]

I posted about my cam bearing failure a while ago. The bearings were toast in the bottom portion. I checked the oiling hole alignment and every other option I could think of. The front was the worst and it got better as you work towards the rear of the block. The last bearing at the rear showed no wear at all I'm using the stock pin and spring setup.

[dwg86]

What was your spring pressure? How much camshaft endplay? I'm still thinking excessive camshaft endplay could be playing a part in cam bearing wear.

[6TIME]

Spring pressures with the LS springs were 90 seat and 245 open. Are you thinking that the cam is sliding forward and back? How would I measure cam endplay since there's no retainer plate? I was under the impression that the way the distributor gears are cut, combined with the load from the oil pump will pull the cam sprocket snug against the block.

[dwg86]

I think excessive camshaft end play could cause bearing wear. There is a lot of pressure on those bearings and the edge of the bearing journal could peel the bearing surface, as the cam is moving forwrd and aft. Also if your cam is walking back and forth, the lifters can't develop a consistant wear patern.

Take the cam plug out from the back of the block, put a dail indicator on the back of the cam, and force the cam front and backwards to measure the end play.

I'm not a stroker expert engine builder, nor do I claim to be. We will never know the longevity of my stroker since my jeep got totalled with 18,000 miles on the stroker, but I used a solid pin in place of the spring and pin to keep the cam from walking. I just ran across the machine shop paperwork last week and it said my installed spring pressure was 130# (which I think is too high. I would like to see 110# to 120#). So that would make my open spring psi 265#(seat pressure plus .501 cam lift x 270# spring rate. 130+135=265).

Silverxj (a meber on this forum) had problems with cam bearing wear. The last time he tore his engine down he used a solid pin to keep the cam from walking as well as a couple other mods that I can't remember. But since then he hasn't had cam bearing problems...knock on wood! So was it the solid pin that fixed it???? don't know.

I don't know if that could be part of your problem, but it is something to look at.

[jsawduste]

Going to throw my hat in the ring. Have to bounce between this post and your other on cam bearing failure.

From your other post you mentioned #1 was the worse and they gotten "better" down the line.

If the cam was walking would`nt it make sense that the bearings would wear somewhat evenly ? Plus the pictures indicate a radial wear pattern rather then a longitudinal.

Combine these observations with the strange harmonics over 3200 I am betting you have a cam that is bent on the front half or journals that are out of round.

Doubting the crank as your post tells of mains that look pretty good and rods that are like new. If the crank was bent you would have seen it. Doubt a balance issue as you seem to have taken a lot of care in part prep and after build checking with no improvement.

Just seems logical to me at least. I`d put the cam in a set of V blocks and measure the run-out

Comments ?

[6TIME]

Cam was within .001" runout at the two middle journals.