TBSS installed and torqued down. What a PITA to get the back three driver side bolts installed and torqued down. I'm taking a little break before I continue all the connections. I'm getting old.....
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I've been doing some compression calculations on my own and other research, and I agree with your thoughts/suggestions. Thank you.
I just finished up conversations with an engine builder I have utilized in the past and with Tech Support from Texas Speed. Both have stated that the engine I want to build utilizing the rotating assembly I purchased (with flathead pistons) utilizing either the 862 or 243 heads should not be a problem (using premium fuel). As I stated in an earlier thread - I already burn Premium. Texas Speed recommends the 243 heads because they breath better at higher RPMs but said 862 should not be a problem. My engine builder also stated yes 243 heads breath better but since I'm looking at lower RPMs that should not be a problem. Even Roger from Vinci Hi-Performance, who I received my upgraded camshaft from, had no issue with my build. Not sure why BBP has such a concern. The type of heads I end up using is not critical at this point - I may even use after market heads (highly unlikely (cost) but possible). Both conversations included their computation of CR and were similar to what I computed. Texas Speed recommended and computed compression ratio based on the standard head gasket thickness of .051". @iamdub - based on the rotating assembly I ordered there should not be pistons out of the hole. More research to follow.
Thank you for all the input. I'm pretty much leaning towards the 243 heads. After a lot of research and talking to several companies, I'm purchasing a fully balanced rotating assembly from Texas Speed. It will be standard crankshaft, rods, bearings and upgraded piston rings and flat head pistons. Should receive the assembly mid-December. Still researching and quite frankly determining the type/size of the head gasket.I'd decide the heads that best compliment the chosen cam. You won't lose any low-end with the 243s so why risk choking (however minimal) at the top end? There's a reason GM switched to them as the standard on the GenIV 5.3. Have you considered pricing out having the 862s CNC'ed? Maybe with larger intake valves (like 2.00" or 2.02") ?
What's the rotating assembly you ordered?
Nice work, looks clean.Completed the TBSS install. Not quite as simple as the multiple you tube posts out there but not that difficult. After install, I needed to reroute some wires and get creative on how I mounted some of the cable brackets on top of the TBSS manifold. I also needed to fix a minor fuel leak but she started right up. Idle was off for about 30-90 seconds but the computer corrected that issue. Disappointed that I was not able to use the Vortec cover, but I haven't given up on that just yet. I can be pretty creative. I still need to record some data for BBP to get the final tune but she runs great. My initial opinion is that I feel that I don't need to step on it as much to get the same result - but when I do really step on it "WOW". Definitely worth the upgrade.
It was more work than i would have thought - thanks.Nice work, looks clean.
Thank you for all the input. I'm pretty much leaning towards the 243 heads. After a lot of research and talking to several companies, I purchasing a fully balance rotating assembly from Texas Speed. It will be standard crankshaft, rods, bearings and upgraded piston rings and flat head pistons. Should receive the assemble mid December. Still researching and quite frankly determining the type/size of the head gasket.
Continue to learn something new everyday. Thanks for the information. I always say if you learn something new in the day then it is a good day. Today has already started off as a good day.If the rotating assembly is all stock specs, then the pistons should be out of the hole a few thou, like .004" - .008" at TDC. This always varies between builds (even from the factory) and even seems to always vary between cylinders. Typically, the corner cylinders (numbers 1, 2, 7 and 8) will be more out of the hole than the center ones (numbers 3, 4, 5 and 6). Always measure your assembled one. You'll need a head gasket at least about .037" more than the highest piston, just to give you rough figures.
Spent a good portion of the day watching football and sitting by the fire (it was chilly here today) but I may have a solution to installing my Vortec engine cover, I will post a picture if it works out. Still running great and no signs of my initial fuel leak.Disappointed that I was not able to use the Vortec cover, but I haven't given up on that just yet.
I have faith in you that you’ll figure something out.I was able to move a few wire bundles slightly and trim my back cable bracket (plastic piece) slightly so it fits better on the TBSS throttle body and now my Vortec engine cover fits in the two back slots and lays nicely on the throttle body. Looks nice. The next problem to overcome is to come up with a way to secure it from the top. The 10mm bolt that normally holds it down is right over the new MAP sensor location. Although the cover fits nicely, I want to find a way to secure it at the top. Back to the drawing board - but I'm closer.
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That’s great news, they must be getting caught up. Maybe they hired on additional staff. My last update took well over a month, that’s when I bought my own tuning software.On Friday, I received my update to the TBSS tune BBP provided for this project. Just minor tweaks. Received this update less than a week after I provided my run data to BBP. I also installed the belt tensioner which I also received on Friday.
I’ve heard that about the Holleys too. Somebody else here I believe was experiencing the whistle and Holley wasn’t being much help to him.I called Texas Speed this morning for basically two reasons.
1. To check the status of my rotating assembly. All parts are in house and the kit is in the queue for balancing. They expect shipping in 5-10 days.
2. To discuss an issue I'm having with the Holley throttle body. I have what I would describe as a "whistle" when I first start up the Tahoe. When it warms up it goes away to the point I can't hear it from the driver's seat. However, open the hood and you can hear it. It gets more pronounced under slight throttle. But under mid to full throttle - nothing. My first thought was vacuum leak, but i confirmed it was not (plus BBP saw my data and there is no vacuum leak that the data shows. Plus I ran a scan and all is good). I took the cold air intake off - wow you can hear it. It is coming from the IAC ports. Put your finger slightly over the hole and it goes away. Did some research, wished I did it before I bought it, and this seems to be a known issue with this throttle body. So I talked to Jared from Texas Speed and he confirmed that this was an issue with this throttle body. I ended up going with his recommendation and buying a FAST throttle body.