Rebuilding/upgrading engine - feedback on buildsheet please

[Red Shift]

I am rebuilding my engine because one cylinder was low on compression (80 psi vs 160 psi on other 9). The machine shop did not find a smoking gun to cause this loss of compression, possible causes are lack of ring tension and out of round cylinder wall (small amount) (both of these were noticed during disassembly). This is my first rebuild and wanted to check that I have everything covered. I would appreciate feedback.

Objective: Rebuild motor to fresh condition while making upgrades that are cost conscious & beneficial to performance and/or reliability. These upgrades include pistons & camshaft (existing camshaft was worn and need replacement).

Current specs:
96 GTS (60,000 miles)
2.4L Roe with 5psi pulley (will change to 8psi pulley during downtime)
VEC 3
B&B headers, high flow cats, Bellanger exhaust
Roe water/**** system – will ONLY be used for the drag strip/races and car will mainly be used without

Build sheet:
Bottom end
• Bore .010” over
• Diamond Racing FI pistons, will keep factory 9.5 CR unless compelled otherwise
• Total Seal stainless chrome top (for high heat) – napier 2nd – 3mm HT oil ring
• Heavy wall tool steel wrist pins
• Factory connection rods
• Federal Mogal 156M main bearings
• Clevite CB1808H rod bearings
• Comp cam for twin screw blower (machine shop to spec unless I provide)
• Cometic MLS head gaskets
• ARP head studs
• Gaskets/Seals: Rear main seal, rear gasket, front cover gasket, oil pan gasket, thermostat housing gasket, intake manifold gasket, thermostat gasket
• Balanced, blueprint and assemble
• Machine crank for improved oiling
• Key crank/balancer

Heads
• Valve seals
• Roe valve spring upgrade (not sure on this one, but will go with these if they’re acceptable. Want to avoid $500 dual valve springs if $200 ones will work - Valve Spring Upgrade Package, 1992-02 - Camshaft and Valvetrain - Roe Racing)
• Manley 1 piece chromoly push rods 5/16 x .080” wall
• Mopar lifters (Sean Roe told me the 92-99 ones are slow bleed and preferred, currently quoted simply Mopar lifters and not sure if that’s what will arrive)

Other upgrades outside of engine:
• Factory clutch (needs replacing)
• Aluminum flywheel (probably Fidanza, needs replacing too)
• Upgrade fuel system – probably 2 Walbros in the tank (the fuel delivery was limited and would hit 100% DC @ 5500RPM on only the 5 psi pulley)
• 170F thermostat (think factory thermostat is currently installed)

Let me know if I missed anything and I appreciate your feedback.

 

[EllowViper]

Very similar to my current set-up.
-Diamond Forged (stock bore) w/total seal ring set (the $390.00 set)
-Stock Rods
-Same main/Rod bearings as you
-Comp Cam Blower Cam w/modified stock rollers (Solid roller w/3/8 Trend pushrods/T&D RR)
-Stock heads with ROE upgraded springs (mildly ported)
-Factory clutch w/Findaza flywheel
-Upgraded fuel system (stock + Walbro -an6 to fuel rails)
-170f T-stat

And so on. Seems to work OK...LOL

 

[coupe]

You mentioned the machine shop spec'ing the cam unless otherwise provided... Not sure who your machine shop is, but I recommend you use a reputable engine guy, specifically a cylinder head and camshaft guy, to spec a camshaft for the build.

 

[speedracervr4]

I would go with the 3/8" dia push rods over the 5/16"

 

[SquadX]

Head work will yield great results and nows the time to do it. Besides that, everything looks good. If your not concerned with more power, which I believe you are since you mentioned moving to an 8lb pulley in the future, dont bother with head work.

Might want to look into replacing waterpump, not sure what year was the issue with the pumps. Also good time to do Abs wires.

I'd call Greg Good to discuss cam/head to compare with what your builder is mentioning. Always nice to have a second opinion and no one better then greg.

whos tuning? Get in touch with DC for a SCT or reflash.

 

[SquadX]

I would go with the 3/8" dia push rods over the 5/16"

I second that. Do it right once and be done.

 

[Red Shift]

Very similar to my current set-up.

Good to know! We've talked on the phone a year back or so about setups. How did you decide on the cam specs? How much power are you making? boost level? water/****?

You mentioned the machine shop spec'ing the cam unless otherwise provided... Not sure who your machine shop is, but I recommend you use a reputable engine guy, specifically a cylinder head and camshaft guy, to spec a camshaft for the build.

That's one thing I've been wondering about. They are a speed shop that builds fast cars. They have set up roots/twin screw cars and know what makes power for them, albeit, they do not work on as many Viper motors of this sort.

I would go with the 3/8" dia push rods over the 5/16"

Why is this? Less deflection to allow more lift?

Head work will yield great results and nows the time to do it. Besides that, everything looks good. If your not concerned with more power, which I believe you are since you mentioned moving to an 8lb pulley in the future, dont bother with head work.

Might want to look into replacing waterpump, not sure what year was the issue with the pumps. Also good time to do Abs wires.

I'd call Greg Good to discuss cam/head to compare with what your builder is mentioning. Always nice to have a second opinion and no one better then greg.

whos tuning? Get in touch with DC for a SCT or reflash.

What is ballpark to get headwork done to make power? It seems to me in $3000+, is that right? I know it will open up the top end, but that's a large incremental cost I may not choose to do. I thought about head work, the cost is the only thing that's making me shy away.

I'll check on the water pump and wires. I've been considering converting to SCT as well. I have some locals in mind for the tuning, might want to learn a bit from them even though I tuned the 5psi myself thanks to the help of the community.



Thank you everyone for the feedback and keep it coming!

 

[EllowViper]

Discussed cam stuff with GG and he gave me some guidelines and a link to the various cam lobes available on the Comp Cams catalogue. Called Comp Cams and discussed lobe options with their tech support and developed a custom grind that could be used with either solid rollers or stock lifters. I have no actual idea as to my "numbers" but am pushing 13+ PSI with a lot of W/M (2 x .063ml nozzles and 2 x .325ml nozzles) Yeah baby.

 

[SquadX]

What is ballpark to get headwork done to make power? It seems to me in $3000+, is that right? I know it will open up the top end, but that's a large incremental cost I may not choose to do. I thought about head work, the cost is the only thing that's making me shy away.

I'll check on the water pump and wires. I've been considering converting to SCT as well. I have some locals in mind for the tuning, might want to learn a bit from them even though I tuned the 5psi myself thanks to the help of the community.



Thank you everyone for the feedback and keep it coming!

Headwork, depending how aggressive, can range from $1400 to way over 3k. I had headwork done to the bowl only in my first viper and it made good power with just that but I had a nice cam by Greg good to match. Pulled like **** with good low end tq as well. Again, just depends on how much power you wanna make. Headwork will allow you to run a larger pulley to make equal power as to running a smaller pulley and no headwork.

 

[plumcrazy]

why is it being bored ? was there an issue ? what is the cause of this rebuild ? if the crank is pinned and you are going to key it, do some homework on that. as far as placement of the key and size of the key. the crank snouts are not billet and anytime you weaken it, it cant be good. just a thought.

good info on talking to greg good about heads and cam.

seems like a lot of work to go thru not to replace the rods as well. you will definitely want to install a real fuel system at this point. are you doing billet mains ?

i wouldn't let any old engine builder do this work on my viper. i want viper specific knowledge and experience

 

[Red Shift]

why is it being bored ? was there an issue ? what is the cause of this rebuild ? if the crank is pinned and you are going to key it, do some homework on that. as far as placement of the key and size of the key. the crank snouts are not billet and anytime you weaken it, it cant be good. just a thought.

good info on talking to greg good about heads and cam.

seems like a lot of work to go thru not to replace the rods as well. you will definitely want to install a real fuel system at this point. are you doing billet mains ?

i wouldn't let any old engine builder do this work on my viper. i want viper specific knowledge and experience

Being bored to correct minor bore distortion noticed by machine shop iirc.

Crank was pinned during Roe install. Machine shop said they want to pin it because it is the correct way to do it, the pinning is just the best way without removing the crank. Thoughts?

Left a message with GG, waiting for return call.

I'm keeping factory rods because it seems others use them fine at Roe power levels. Not planning to go with billet mains. Both of these add a big chunk of cost that may not be necessary, disagree?

I'm considering using Late Model Engine (LME) in Houston. They do build about 1 Viper motor a month, but are mainly a LSX shop.

I appreciate your feedback Plumcrazy.

 

[plumcrazy]

keying the crank can be done in the car. not many have the capability to do it though. if youre gonna pin it, id use the exact same pins to not weaken the crank any more. search and ask around about that.

as long as you stick to those power levels, im sure you will be fine.

was it a nitrous car previously ? mine was and had distorted cylinder walls, thats why i ask.

make sure to keep after GG, he is worth the chase and especially since you are kinda local to him

 

[speedracervr4]

Why is this? Less deflection to allow more lift?

I was told by GG that the 5/16" dia will flex and cause problems...Approx $90 more to go with the 3/8"...

 

[Viperguynick]

I had LME build me a fully forged and blue-printed LS6 for my previous Formula. Top notch work, expensive, but definitely a great build. Car made great power, and I had no worries about durability.

Nick

 

[Red Shift]

keying the crank can be done in the car. not many have the capability to do it though. if youre gonna pin it, id use the exact same pins to not weaken the crank any more. search and ask around about that.

as long as you stick to those power levels, im sure you will be fine.

was it a nitrous car previously ? mine was and had distorted cylinder walls, thats why i ask.

make sure to keep after GG, he is worth the chase and especially since you are kinda local to him

I'll check into the crank more. Thanks.
It was never said to be a nitrous car, then again, that's not usually highly advertised. I am not the 1st owner so who knows... I wonder why nitrous would cause that. Any ideas?
Thanks for the GG recommendation.

I was told by GG that the 5/16" dia will flex and cause problems...Approx $90 more to go with the 3/8"...

Cool! I'll ask about it when I speak with him. I've heard mixed reviews on going 3/8" that it is not always necessary unless using a more aggressive valve train.

I had LME build me a fully forged and blue-printed LS6 for my previous Formula. Top notch work, expensive, but definitely a great build. Car made great power, and I had no worries about durability.

Nick

Good to hear Nick! I see you're not in Houston now. Did you used to live here are did you order the motor from them?

 

[EllowViper]

Greg told me the beefier push rods tend to settle the drive train down a bit as well. These aren't hi-revving engines anyways so focusing on lightening the valvetrain isn't that big of an issue. Beehive springs, titanium retainers & locks as well as SS valves seem to be the most logical areas folks focus on when seeking weight savings. To overcome the increase seat pressure replacement spring will introduce along with higher cylinder (opening) pressures that the exhuast valves will be physically experiencing (i.e.pushing against combustion gasses when they try to open) you can quickly see the need for some stout pushrods. Aggressive cam profiles where opening/closing velocities are extreme also introduce additive stresses on the pushrods. The list goes on...

 

[Red Shift]

Greg told me the beefier push rods tend to settle the drive train down a bit as well. These aren't hi-revving engines anyways so focusing on lightening the valvetrain isn't that big of an issue. Beehive springs, titanium retainers & locks as well as SS valves seem to be the most logical areas folks focus on when seeking weight savings. To overcome the increase seat pressure replacement spring will introduce along with higher cylinder (opening) pressures that the exhuast valves will be physically experiencing (i.e.pushing against combustion gasses when they try to open) you can quickly see the need for some stout pushrods. Aggressive cam profiles where opening/closing velocities are extreme also introduce additive stresses on the pushrods. The list goes on...

Thanks for the info Ellow. Just got off the phone with Greg. Damn he knows his stuff!

 

[plumcrazy]

another option: ViperAlley Classifieds - Proline Racing Stroker engine w Greg Good heads - Powered by PhotoPost Classifieds

tony can be trusted and you might wanna see what kind of deal he can make. be trade in your engine on it ?

 

[Red Shift]

another option: ViperAlley Classifieds - Proline Racing Stroker engine w Greg Good heads - Powered by PhotoPost Classifieds

tony can be trusted and you might wanna see what kind of deal he can make. be trade in your engine on it ?

Thanks for the tip Plum. Tony just shipped it out yesterday!

Thanks to Tony, Greg Good, Nick Arevalo, Sean Roe and the board members for helping with questions during the engine replacement.